108OAG81

Gen. 81] 81

TRANSPORTATION

LOCAL GOVERNMENT – PREEMPTION – TRAFFIC STOPS –

WHETHER A LOCAL ORDINANCE PROHIBITING LOCAL

POLICE OFFICERS FROM STOPPING DRIVERS SOLELY FOR

CERTAIN TRAFFIC OFFENSES WOULD BE PREEMPTED BY

THE MARYLAND VEHICLE LAW

September 15, 2023

The Honorable Evan Glass

President, Montgomery County Council

The Maryland Vehicle Law—the State statute regulating the

use of motor vehicles—defines numerous offenses for which police

officers may issue traffic citations. Motor vehicle offenses can be

categorized as either “primary” or “secondary.” If a police officer

observes a primary offense, they may ordinarily stop and cite the

driver for that offense, without more. But an officer cannot stop a

driver for a secondary offense standing alone. Instead, an officer

may issue a citation for a secondary offense only after stopping the

driver for a separate primary offense. A bill pending before the

Montgomery County Council—the Safety and Traffic Equity in

Policing Act, or “STEP Act”—would require Montgomery County

police officers to treat certain traffic offenses as secondary, even

though the Maryland Vehicle Law has not defined them as such.

The STEP Act would also limit Montgomery County officers’

ability to ask for consent to search a vehicle, or its occupants,

during a traffic stop.

On behalf of the Montgomery County Council, you requested

an opinion of the Attorney General on whether the Maryland

Vehicle Law would preempt the STEP Act. In accordance with our

policy on opinion requests, you provided a memo from the County

Attorney concluding that the Vehicle Law would preempt the

provisions of the STEP Act relating to secondary offenses but that

the STEP Act’s remaining provisions would be valid. You also

provided a memo from a Legislative Attorney for the Council,

concluding that the Vehicle Law would not preempt any portion of

the STEP Act.

In our view, the Vehicle Law would expressly preempt the

STEP Act’s provision designating certain traffic offenses as

secondary. Under the Vehicle Law, no local government may

make or enforce a “local law, ordinance, or regulation on any

subject covered by the Maryland Vehicle Law.” Md. Code Ann.,

82 [108 Op. Att’y

Transp. (“TR”) § 25-101.1(b)(3). As we will explain, the Maryland

Vehicle Law covers the subject of which motor vehicle offenses

are subject to primary enforcement and which are subject to

secondary enforcement. More specifically, the Vehicle Law

establishes a general rule that all motor vehicle offenses are subject

to primary enforcement. It then exempts certain specific offenses

from that rule, explicitly providing secondary enforcement for

those specific offenses. Because the Vehicle Law addresses the

subject of primary versus secondary enforcement, and because the

General Assembly has chosen to designate certain offenses as

secondary while leaving the rest as primary, a local law designating

further offenses as secondary would address a subject that the

Vehicle Law covers and would thus be preempted.

Although the Vehicle Law reserves certain powers to local

governments, none of those reserved powers would authorize the

secondary-offense provisions of the STEP Act. To be clear, we do

not question a local government’s general authority to establish

rules for its own police department. Nor do we address a local

legislative body’s ability to set enforcement priorities for its local

police department in areas not subject to express preemption. We

conclude only that, whatever legislative authority a local

government otherwise has, the General Assembly has overridden

that authority for subjects the Vehicle Law addresses, including the

subject of which motor vehicle offenses are secondary.

On the other hand, the Vehicle Law would not preempt the

STEP Act’s remaining provisions. In particular, the Vehicle Law

would not preempt the STEP Act’s limitation on consent searches.

That provision would preclude an officer from requesting consent

to search a vehicle or its occupants during a traffic stop, unless

there is at least reasonable suspicion to believe a crime has been

committed. The Maryland Vehicle Law does not address the

subject of searches during traffic stops. The consent-search

provision also would not tread on an impliedly preempted field.

Nor would it conflict with any provision of the Vehicle Law,

because, again, the Vehicle Law does not address searches. There

is thus no basis to say that the Vehicle Law would preempt the

consent-search provision.1

1

We received three sets of comments on this opinion request,

generally supporting the STEP Act on legal or policy grounds. Angela

J. Davis et al., Testimony in Support of the Safety and Traffic Equity in

Policing (STEP) Act—Bill 12-23 (July 5, 2023) (“Davis Comments”);

Robert Landau, Comments of Robert Landau on the Legality of the

Montgomery County Bill 12-23 (July 25, 2023); Letter from Chelsea J.

Gen. 81] 83

I

Background

A. Traffic Stops

Traffic stops are the most common interaction between police

officers and members of the public in the United States.

Montgomery County Office of Legislative Oversight, OLO Report

No. 2021-10, A Study on Reassigning Traffic Enforcement from the

Montgomery County Police Department to the Montgomery

County Department of Transportation 5 (2021) (“OLO Report”).

Maryland law empowers police officers to order a driver to stop by

means of a “visual or audible signal.” TR § 21-904. Because the

driver, once pulled over, is not free to leave at will, a traffic stop is

a “seizure” governed by the Fourth Amendment and Article 26 of

the Maryland Declaration of Rights.2 See, e.g., Byndloss v. State,

391 Md. 462, 465 & n.1, 480 (2006). Ordinarily, though, an officer

can conduct a traffic stop without a warrant if they have reasonable

suspicion—usually through direct observation—that the driver is

violating the motor vehicle laws. State v. Williams, 401 Md. 676,

690-91 (2007). Indeed, the Maryland Vehicle Law affirmatively

authorizes officers to issue citations for motor vehicle offenses,

which in turn implies the power to stop the driver. See TR

§ 26-201. For some specific offenses, though, the authority to

conduct a stop is limited by statute, as we discuss further below.3

Crawford, Esq., to Hon. Anthony G. Brown, Attorney General (Aug. 10,

2023). We thank the commenters for their views, and we have

considered their comments in developing the analysis below.

2

Article 26 provides: “That all warrants, without oath or affirmation,

to search suspected places, or to seize any person or property, are

grievous and oppressive; and all general warrants to search suspected

places, or to apprehend suspected persons, without naming or describing

the place, or the person in special, are illegal, and ought not to be

granted.” Md. Decl. Rights Art. 26. The scope of Article 26’s protection

against searches and seizures is generally the same as the Fourth

Amendment’s. See, e.g., King v. State, 434 Md. 472, 482-83 (2013).

3

While the default rule is that motor vehicle offenses in Maryland are

misdemeanors, see TR § 27-101, some are felonies, e.g., TR

§ 20-102(c)(3) (leaving the scene of an accident when the defendant

knew or reasonably should have known that the accident resulted in

serious bodily injury or death), and others are subject only to civil

penalties, e.g., TR § 21-1414(c) (failing to pay a toll assessed by a video

monitoring system). We do not consider the question of when an officer

can stop a driver who has committed only a civil offense.

84 [108 Op. Att’y

Constitutional limits also control what the officer can do once

the driver has been stopped. A stop generally cannot last longer

than necessary to accomplish its original purpose, which is

normally to investigate the traffic violation and issue a warning or

citation if appropriate. See, e.g., Ferris v. State, 355 Md. 356, 372

(1999). But an officer may continue to detain the vehicle if the

officer has reasonable suspicion that some other criminal activity

is afoot. Id. And an officer may also request consent to search the

vehicle or its occupants. See id.; Scott v. State, 247 Md. App. 114,

132, 150-52 (2020). A warrantless search based on consent is

ordinarily valid with or without reasonable suspicion or probable

cause, even in the context of a traffic stop. See State v. Green, 375

Md. 595, 609-10 (2003); Gamble v. State, 318 Md. 120, 123-24

(1989). But see Md. Code Ann., Crim. Proc. (“CP”) § 1-211(c)

(providing that evidence obtained through certain cannabis-related

searches is inadmissible even if obtained with consent).4

Traffic stops serve an important public safety function. They

enable officers to deter and stop dangerous driving, which in turn

helps reduce crashes and injuries. OLO Report at i, 5. But

advocates and researchers have raised concerns about racial

disparities in the frequency of traffic stops, especially in the

frequency of traffic stops where the officer’s primary motivation is

to search for evidence of other crimes. Id. at 76-77. Such

“investigatory” stops have been upheld against Fourth Amendment

challenge by the United States Supreme Court, see Whren v. United

States, 517 U.S. 806, 813 (1996), but are often criticized as

“pretextual,” see, e.g., Wayne R. LaFave, The “Routine Traffic

Stop” from Start to Finish: Too Much “Routine,” Not Enough

Fourth Amendment, 102 Mich. L. Rev. 1843, 1852-61, 1902-03

(2004); Snyder v. State, No. 1127, Sept. Term, 2021, 2023 WL

1497289, *8-*10 (Md. App. Ct. Feb. 3, 2023) (unreported)

(Friedman, J., concurring) (criticizing Whren and arguing that the

Supreme Court of Maryland should adopt a rule against

“pretextual” stops under Article 26 of the Declaration of Rights).5

4

Other exceptions to the warrant requirement, such as the “plain

view” exception or the “automobile exception,” may apply in the context

of a traffic stop. See Livingston v. State, 317 Md. 408, 412-13 (1989);

107 Opinions of the Attorney General 153, 162-63, 166 n.20 (2022).

However, because the STEP Act does not address these exceptions, we

need not discuss them here.

5

As the law professors’ comments to our Office put it, “some police

officers use traffic stops to racially profile black and brown drivers.

They use traffic stops as a pretext for stopping these drivers so they can

look inside their cars and ask for consent to search, even though they

Gen. 81] 85

Research indicates that Black and Latino drivers are stopped at

higher rates than white drivers for “minor” or “technical” offenses

(i.e., those that do not directly threaten a crash or injury). OLO

Report at 76-77 & nn.4-6 (citing social science literature). And

such “technical” violations are the most common basis for

“investigatory” stops. See id. The concern, then, is that police

freedom to conduct traffic stops for “technical” violations is a

major source of racial disparity in traffic enforcement.

In Maryland, 125 law enforcement agencies conducted more

than 482,000 traffic stops in 2021. See Governor’s Office of Crime

Prevention, Youth, and Victim Services, Race-Based Traffic Stop

Data Dashboard, https://goccp.maryland.gov/data-dashboards/traffic-

stop-data-dashboard/ (enter “2021” for “Year”) (last visited Sept.

12, 2023) (“Data Dashboard”). There are several law enforcement

agencies with the power to make traffic stops in Montgomery

County (or at least parts of the County), including the Montgomery

County Police Department (“MCPD”), the Maryland State Police,

the Montgomery County Sheriff’s Office, and municipal police

departments. See id.; OLO Report at 13 n.17. Because some of

these agencies are created by local law as arms of local

government, the question arises whether local governments can

regulate the ability of their police departments to make traffic stops.

The answer to that question depends on the preemptive scope of

the Maryland Vehicle Law.

B. The Maryland Vehicle Law

The Maryland Vehicle Law (Titles 11 through 27 of the

Transportation Article, Maryland Code) regulates motor vehicle

ownership and operation in the State. Its purpose is to ensure “that

traffic shall move smoothly, expeditiously and safely [and] that no

legitimate user of the highway . . . shall be killed, injured or

frustrated in such use by the improper behavior of others.”

Uniform Vehicle Code vii (National Comm. on Unif. Traffic Laws

& Ordinances 1968 rev.); see also Committee to Study Revision of

the Motor Vehicle Laws, Proposed Revision of the Motor Vehicle

Laws of the State of Maryland iii (1968) (explaining that most

recent substantive revision of the Vehicle Law was based on the

Uniform Vehicle Code).

The Vehicle Law expressly limits the lawmaking authority of

local governments. “Except as otherwise expressly authorized . . .

have no legal grounds to suspect them of criminal behavior.” Davis

Comments at 2.

86 [108 Op. Att’y

no local authority or political subdivision of this State may . . .

make or enforce any local law, ordinance, or regulation on any

subject covered by the Maryland Vehicle Law.” TR § 25-101.1(b)(3).

The statute then reiterates that “[t]he provisions of the Maryland

Vehicle Law prevail over all local legislation and regulation on any

subject with which the Maryland Vehicle Law deals.” TR

§ 25-101.1(c)(1). At the same time, the Vehicle Law grants certain

express powers to local governments, including the power of

“[r]egulating traffic by means of police officers or traffic control

devices,” TR § 25-102(a)(2), and of “regulating or prohibiting the

stopping, standing, or parking of vehicles,” TR § 25-102(a)(1).

The General Assembly enacted the earliest precursor of the

Vehicle Law in 1904, just a few years after the first automobiles

appeared in Maryland. 1904 Md. Laws, ch. 518; see also Carriage

Without Horses, Balt. Sun, Dec. 20, 1898, at 10 (announcing the

expected arrival in February 1899 of the first “horseless carriage”

in Baltimore). As cars proliferated, the rules governing them grew

more complex, and legislators became more interested in ensuring

statewide uniformity. In 1916, the General Assembly prohibited

local governments from establishing their own speed limits,

licensing or registration requirements, or motor vehicle taxes. 1916

Md. Laws, ch. 687. But State authorities soon decided stronger

preemption was needed. In 1927, the General Assembly expressly

preempted local lawmaking on any subject covered by the State

vehicle law.6 That preemption provision remains in effect, with

6

As originally enacted, the preemption provision read:

Except to the extent that they may be specifically

authorized by other provisions of this sub-title

[Article 56, Subtitle “Motor Vehicles”], no city,

county or other political sub-division of this State

shall have the right to make or enforce any

ordinance or regulation upon any subject for

which provision is made in this sub-title. The

provisions of this sub-title (except as herein

otherwise specifically provided), are intended to

be exclusive of all local and municipal legislation

or regulations, upon the various subjects with

which this sub-title purports to deal, and all public

local laws, ordinances and regulations,

inconsistent or identical therewith, or similar or

equivalent thereto, are hereby repealed; and the

charters of all municipal corporations of this State

are hereby modified so as to prohibit such

corporations from making or enforcing any

Gen. 81] 87

only limited changes, as today’s TR § 25-101.1. Former Attorney

General Thomas H. Robinson, who drafted the preemption statute,

explained that it was intended to “remove all doubt . . . and to make

it clear that the provisions of the general motor vehicle law were

exclusive of all public local laws and municipal ordinances and

regulations, covering the same subject matter.” 14 Opinions of the

Attorney General 210, 214 (1929).

The General Assembly apparently had second thoughts about

the preemption provision’s breadth. In 1929, it amended the

preemption language to recognize local governments’ authority to

adopt “reasonable traffic regulations” notwithstanding the State

law. 1929 Md. Laws, ch. 319. But in 1943, as part of a general

substantive revision of the Vehicle Law, the General Assembly

repealed that exception, restoring the preemption provision to its

1927 scope. 1943 Md. Laws, ch. 1007.

There have been two comprehensive revisions of the Vehicle

Law. Each has drawn on the Uniform Vehicle Code developed by

the National Committee on Uniform Traffic Laws and Ordinances.

The first revision, in 1943, aimed at “promoting greater uniformity

and thereby achieving greater safety.” Report of the Commission

on the Revision of the State Motor Vehicle Laws 8 (1942) (“1942

Report”). As mentioned, this revision (among other changes)

repealed the authority of local governments to adopt “reasonable

traffic regulations.” At the same time, the General Assembly

codified a list of express powers of local governments, drawn from

the Uniform Code. These included the power of “[r]egulating

traffic by means of peace officers or traffic control devices” and

“[r]egulating the standing or parking of vehicles.” Compare 1943

Md. Laws, ch. 1007 (enacting Art. 66 ½, § 135), with Uniform

Vehicle Code, Uniform Act Regulating Traffic on Highways § 28,

at 5 (Nat’l Conference on Street & Highway Safety 1938 rev.); see

also 1942 Report at 2.

The second revision, in 1970, made no substantive changes

either to the preemption provision or to the two express powers

mentioned above. 1970 Md. Laws, ch. 534 (enacting Art. 66 ½,

§§ 15-101, 15-102); see also Maryland Dep’t of Motor Vehicles,

Motor Vehicle Laws Revision 495-98 (1969) (comparing newly

ordinance or regulations in violation of this

section.

1927 Md. Laws, ch. 520, § 3 (codified as Art. 56, § 171-A).

88 [108 Op. Att’y

revised sections to prior law).7 Finally, a non-substantive code

revision in 1977 adopted the current section numbering, codifying

the preemption provision at TR § 25-101.1 and the list of local

powers at TR § 25-102. 1977 Md. Laws, ch. 14.

C. Primary and Secondary Offenses

As discussed above, officers ordinarily have broad authority

to stop drivers for motor vehicle violations. Williams, 401 Md. at

690-91. And a driver’s consent to a search can be voluntary even

if obtained during a traffic stop. Green, 375 Md. at 614-15. But

legislators can impose stricter limits on searches and seizures—

including traffic stops—than the Constitution (State or federal)

requires. See 107 Opinions of the Attorney General 153, 189-90

(2022) (concluding that, even if vehicle searches based on the odor

of cannabis would be constitutional, the General Assembly could

prohibit such searches); see also CP § 1-211 (limiting law

enforcement officers’ authority to conduct stops and searches

based solely on the odor of cannabis).

One potential statutory limit on officers’ authority to stop

vehicles is the designation of certain motor vehicle offenses as

“secondary.” A secondary violation is conduct that, although

unlawful, does not—by itself—allow an officer to initiate a traffic

stop or issue a citation. See, e.g., Christi Schofield, Comment,

Texas, Are We There Yet?, 15 Tex. Tech Admin. L.J. 399, 410

(2014) (discussing status of texting while driving as a primary or

secondary offense). The officer may only issue a citation for a

secondary offense if they have already stopped the driver for a

“primary offense” (meaning any offense that has not been

designated as secondary). Id.

The Maryland Vehicle Law expressly designates certain

traffic offenses as secondary offenses. For example, the Vehicle

Law prohibits driving “with any object, material, or obstruction

hanging from the rearview mirror that interferes with the clear view

of the driver through the windshield.” TR § 21-1104(c)(3). But a

7

The 1970 version retained prior language providing local

governments power to “[r]egulat[e] the standing or parking of vehicles”

even though the most recent Uniform Vehicle Code revision referred to

“[r]egulating or prohibiting stopping, standing or parking.” Uniform

Vehicle Code § 15-102(a)(1) (1968 rev.) (emphasis added). The word

“stopping” was later added to the Maryland provision as part of non-

substantive code revision in 1977; the Revisor’s Note stated that its

omission had been an “oversight.” 1977 Md. Laws, ch. 14 (Revisor’s

Note to TR § 25-102).

Gen. 81] 89

“police officer may enforce this [prohibition] only as a secondary

action when the police officer detains a driver of a motor vehicle

for a suspected violation of another provision of the Code.” TR

§ 21-1104(c)(3)(ii). The Vehicle Law also establishes secondary-

offense status for driving with a partly obscured license plate, TR

§ 13-411(c), violating passenger restrictions on provisional license

holders, TR § 21-1123, driving without headlights in rainy

conditions, TR § 22-201.2, and failure to wear a seatbelt by a

passenger over 16 in the back seat, TR § 22-412.3(c)(3). All of

these remain traffic violations, but they do not, standing alone,

provide a basis for an officer to stop a vehicle or cite a driver.

D. The STEP Act

The STEP Act is a bill pending before the Montgomery

County Council. The bill seeks to reduce racial disparities in traffic

enforcement while promoting traffic safety. Bill No. 12-23,

Montgomery County Council (Feb. 28, 2023) (“STEP Act”)

(proposed Montgomery County Code § 35-27(a)). The STEP Act

would make two major changes to MCPD officers’ traffic

enforcement authority. First, it would designate several offenses

under the Motor Vehicle Law as secondary offenses, beyond those

already identified as secondary by the Vehicle Law itself. Id.

(proposed § 35-27(c), (d)). Second, it would limit the ability of

MCPD officers to request consent to search during traffic stops. Id.

(proposed § 35-27(e)). The bill would also impose reporting

requirements and prohibit collective bargaining over the subjects it

covers. Id. (proposed §§ 33-80, 35-28). There is an express

severability clause. Id. (proposed § 35-29).

The secondary-offense provisions are found in proposed new

sections § 35-27(c) and (d) of the Montgomery County Code. The

STEP Act would designate as a secondary offense: Any offense

under Title 13 of the Transportation Article, relating to vehicle

titles, registration, and license plates; any offense under Title 16,

relating to driver’s licenses; any offense under Title 17, relating to

required insurance; fourteen enumerated provisions of Title 22,

relating to vehicle equipment;8 and §§ 21-203(c) and 21-503,

8

Specifically: driving a vehicle in an unsafe condition or with

improper equipment (§ 22-101(a)); driving without headlights in low-

visibility conditions (§ 22-201.1); driving without headlights while

operating windshield wipers due to low visibility (§ 22-201.2) (which is

already a secondary offense under State law); driving a vehicle that does

not have at least two headlamps (§§ 22-203(b) and 22-226(a)); driving a

vehicle that does not have the rear license plate illuminated

90 [108 Op. Att’y

which prohibit jaywalking (collectively, the “covered provisions”).

STEP Act (proposed § 35-27(c)). The covered provisions together

accounted for around 10–20% of all traffic stops by the MCPD in

2021.9 If the STEP Act were enacted, an MCPD officer could not

“stop or detain a person operating a motor vehicle, solely for a

suspected violation of” one of the covered provisions. Id.

Under the STEP Act, an officer could still issue a citation for

a secondary offense (under one of the covered provisions) after

stopping a driver for a primary offense. Even then, however, an

officer could not cite a driver for a first violation of one of the

covered provisions but rather would be required to give a verbal or

written warning. STEP Act (proposed § 35-27(d)).

The second major topic of the STEP Act is searches during

traffic stops—specifically, officers’ ability to request consent to

search. Under the bill, an officer conducting a traffic stop could

“only ask for permission to conduct a consent search of a person or

vehicle if reasonable suspicion or probable cause for a criminal

offense arises during the stop.”10 STEP Act (proposed § 35-27(e)).

(§ 22-204(f)); driving a vehicle with inadequate stop lamps or turn signal

lamps (§§ 22-206 and 22-219(a)); driving a vehicle that does not have

lamps of the required colors (§ 22-209); driving a vehicle that does not

have required rear reflectors (§ 22-210(c)); driving a vehicle with lamps

that project “glaring or dazzling light” (§ 22-219(g)); using high beams

when approaching another vehicle (§ 22-223); driving a vehicle with

window obstructions (§ 22-404(a)); and driving a vehicle without safety

glass or with window tints that are too dark (§ 22-406). The bill clarifies

that notwithstanding the bill’s designation of various headlight-related

offenses as secondary, an officer would still be able to stop a vehicle that

does not have at least one front and rear light illuminated. STEP Act

(proposed § 35-27(c)(2)(O)).

9

In 2021, violations of Title 13 (registration and license plates)

accounted for 9.08% of all traffic stops by the MCPD; violations of Title

16 (driver’s licenses) for 1.72%; and equipment violations under Title 22

for 10.19% (although the data lump all equipment violations together, so

there is no data on the number of traffic stops for the specific Title 22

provisions covered by the STEP Act). See Data Dashboard (enter

“Montgomery County Police Department” for “Agency” and “2021” for

“Year”). There was no data on traffic stops under Title 17.

10

The STEP Act would also provide that an officer may not extend a

traffic stop beyond its original purpose unless there is reasonable

suspicion of another crime. STEP Act (proposed § 35-27(e)(1)). Other

than eliminating consent as a basis for extending a stop, this is consistent

with what the Fourth Amendment and Article 26 already require. See

Ferris, 355 Md. at 372.

Gen. 81] 91

The STEP Act would thus eliminate “investigatory” traffic stops in

which an officer requests consent to search for evidence of crimes

beyond the motor vehicle offense that authorized the stop, without

particularized suspicion of the driver or vehicle at issue. See OLO

Report at 77. This rule would apply to all MCPD traffic stops, not

just traffic stops where a secondary offense is involved. See STEP

Act (proposed § 35-27(e)).

The STEP Act limits its coverage to the MCPD. It would not

affect traffic stops by the State Police, municipal police, and other

law enforcement agencies. STEP Act (proposed § 35-26(a))

(defining “police officer” as “a sworn officer employed by the

County”). An officer conducting a traffic stop or search in

violation of the STEP Act would be subject to discipline. Id.

(proposed § 35-27(f)).

II

Analysis

You have asked whether the Maryland Vehicle Law would

preempt the proposed STEP Act. Preemption occurs when State

law precludes a local government from enacting a measure that

would otherwise be within the local government’s power.

Preemption may result from the express terms of a State statute,

may be implicit in the comprehensiveness of a State statute’s

coverage, or may occur when a local law directly conflicts with

State law. See, e.g., 101 Opinions of the Attorney General 35, 55

(2016). As we will explain, the Maryland Vehicle Law expressly

preempts local governments from making law on any subject the

Vehicle Law covers. And the Vehicle Law covers the subject of

primary versus secondary offenses: it establishes a default rule of

primary enforcement by empowering officers to issue a citation for

any Vehicle Law offense, while mandating secondary enforcement

for some specific offenses. Because the General Assembly has

addressed the issue, local legislation cannot make different

determinations on which traffic offenses should be primary and

which secondary. But because the Vehicle Law says nothing about

searches during traffic stops, it would not preempt the STEP Act’s

limitations on consent searches. Nor would those limitations on

searches conflict with any provision of the Vehicle Law.

A. General Principles of Preemption

Montgomery County has adopted the charter home rule form

of government. See generally Md. Const., Art. XI-A. This status

grants the county broad authority to enact local laws. See, e.g.,

92 [108 Op. Att’y

Montgomery Citizens League v. Greenhalgh, 253 Md. 151, 160-62

(1969). But a charter county’s power has limits. Even a local law

that is otherwise within the county’s power must yield if State law

preempts it. See, e.g., Edwards Sys. Tech. v. Corbin, 379 Md. 278,

296-97 (2004).

State law can preempt local law in one of three ways. E.g.,

Worton Creek Marina, LLC v. Claggett, 381 Md. 499, 512 (2004).

First, express preemption occurs when a State statute explicitly

precludes local governments from making law in a certain area. 98

Opinions of the Attorney General 60, 88 (2013). We interpret

express preemption provisions under the normal rules of statutory

construction. See, e.g., 75 Opinions of the Attorney General 308,

311-12 (1990). Under those rules, our primary objective is to

determine and effectuate the intent of the General Assembly,

beginning with the ordinary meaning of the language used,

considered in context, and considering other sources of meaning,

such as legislative history and the statute’s general purpose. E.g.,

107 Opinions of the Attorney General 196, 203 (2022).

The second form of preemption is implied preemption. “State

law can preempt local ordinances by implication when ‘the

ordinance deals with an area in which the General Assembly has

acted with such force that an intent to occupy the entire field must

be implied.’” Board of County Comm’rs v. Perennial Solar, LLC,

464 Md. 610, 619 (2019) (quoting Howard County v. Potomac

Elec. Power Co., 319 Md. 511, 522 (1990)). But a statute with an

express preemption provision is unlikely to implicitly preempt, in

this way, more than it expressly preempts. See Browning-Ferris,

Inc. v. Anne Arundel County, 292 Md. 136, 153 (1981); see also

107 Opinions of the Attorney General 74, 83-84 (2022) (discussing

this point in the context of federal-state preemption).

Third, conflict preemption occurs when a local law directly

conflicts with State law. Maryland courts have recognized two

sub-types of conflict preemption. First, a “verbal” conflict, also

known as “prohibit-permit” conflict, exists when the local law

would authorize something State law prohibits or would prohibit

something State law expressly authorizes. 98 Opinions of the

Attorney General at 91; Worton Creek, 381 Md. at 513. Second, a

“functional” conflict exists when the impact of the local law

Gen. 81] 93

interferes with the State law’s function. 96 Opinions of the

Attorney General 139, 144 (2011).11

B. The STEP Act’s Secondary-Offense Provisions

We first consider whether the Vehicle Law would preempt the

STEP Act’s secondary-offense provisions. Under the Vehicle

Law, a local government may not “make or enforce any local law,

ordinance, or regulation on any subject covered by the Maryland

Vehicle Law” except as expressly authorized. TR § 25-101.1(b)(3);

accord TR § 25-101.1(c)(1). Our Office has described this

provision as representing “some of the most far-reaching

preemption in State law.” Letter from Kathryn M. Rowe, Assistant

Attorney General, to Del. Brooke E. Lierman, at 1 (Oct. 10, 2018);

see also 93 Opinions of the Attorney General 126, 134 (2008)

(characterizing the Vehicle Law’s express preemption provision as

especially “open-ended”).

To determine whether the Vehicle Law preempts a local law

under § 25-101.1, we must answer three questions: First, is the

local measure at issue a “local law, ordinance, or regulation”?

Second, does it address a “subject covered by the Maryland Vehicle

Law”? Third, does any other State law “expressly authorize[]” the

measure? If the measure is a “local law, ordinance, or regulation”

on a “subject covered by the Maryland Vehicle Law,” and no other

State law expressly authorizes it, the local enactment is preempted.

Answering the first question is straightforward: if enacted by

the County Council, the STEP Act would clearly be a “local law”

or “ordinance” within the meaning of TR § 25-101.1. The other

two questions require more detailed analysis.

1. Subject Covered by the Maryland Vehicle Law

As to the second question, our opinion is that the STEP Act’s

secondary-offense provisions address a “subject covered by the

Maryland Vehicle Law”: the determination of which motor vehicle

offenses are primary and which are secondary.

11

Federal law also recognizes “obstacle” or “frustration of purpose”

preemption, when a state law “stands as an obstacle to the

accomplishment and execution of the full purposes and objectives of

Congress.” E.g., Arizona v. United States, 567 U.S. 387, 399 (2012)

(quoting Hines v. Davidowitz, 312 U.S. 52, 67 (1941)). But Maryland

courts have so far declined to import this doctrine into the State versus

local law context. E.g., County Council of Prince George’s County v.

Chaney Enters. Ltd. P’ship, 454 Md. 514, 541 n.19 (2017).

94 [108 Op. Att’y

Several of our prior opinions have considered whether

particular local laws addressed subjects covered by the Vehicle

Law. For example, in one opinion, we concluded that when State

law required minors (and only minors) to wear motorcycle helmets,

Baltimore City could not impose the same requirement on adults,

because the Vehicle Law covered the subject of “safety equipment

required of motorcycle operators,” 65 Opinions of the Attorney

General 483, 484, 486-87 & n.7 (1980). Later, our Office

concluded in a different opinion that a city ordinance could address

charitable and employment solicitations from sidewalks, from

vehicles, and in parking lots, where the Vehicle Law addressed

only solicitation by pedestrians standing in the roadway. 93

Opinions of the Attorney General 31, 33, 36-37 (2008). Another

opinion concluded that a city could regulate parking on private

property with the property owner’s consent because the Vehicle

Law only regulates parking on private property without the

property owner’s consent. 73 Opinions of the Attorney General

252, 254-55 (1988).12

As these opinions illustrate, the level of generality at which

the Vehicle Law’s preempted “subjects” should be defined is not

always clear. Our 2008 opinion on roadway solicitation, for

example, would presumably have reached the opposite result if we

had defined the covered “subject” as solicitation in a roadway

rather than solicitation by pedestrians in a roadway; this would

have preempted the local ban on solicitation from vehicles.

Similarly, our 1980 opinion on motorcycle helmets would likely

have reached the opposite result if it had defined the covered

subject as “motorcycle safety equipment required of minors,”

thereby saving Baltimore City’s adult helmet requirement from

preemption.

Even though it may not always be clear how broadly (or

narrowly) to define the “subjects” covered by the Vehicle Law, it

is clear that when a local law addresses a matter that specific

provisions of the Vehicle Law also directly address, the local law

12

In Mayor & City Council of Baltimore v. Hart, 395 Md. 394 (2006),

Maryland’s highest court held that the Vehicle Law did not preempt a

Baltimore City Police Department general order setting rules for

emergency vehicles that were stricter than State law, id. at 406.

However, for reasons that are not clear from the opinion or briefing, the

question of express preemption under TR § 25-101.1 was not presented

in Hart. See id. at 406-10 (discussing conflict preemption only). It is

also possibly relevant that Hart involved a departmental order rather than

a “local law, ordinance, or regulation.” See id. at 404; see also infra Part

II.B.3.

Gen. 81] 95

will be preempted. The level of generality problem has arisen only

when a local law has addressed something that the Vehicle Law

does not directly address—such as motorcycle helmets for adults

or solicitation from cars—but that was arguably related to, and thus

possibly part of the same broader “subject” as, a matter the Vehicle

Law did address. But there is no question that the Vehicle Law

would preempt a local law on a subject the Vehicle Law directly

speaks to. See, e.g., 58 Opinions of the Attorney General 462, 464

(1973) (concluding that a local ordinance, intended to prevent

debris from falling off trucks, was preempted because the Vehicle

Law also had a provision requiring the securing of truck loads).

Here, the Vehicle Law directly addresses which offenses are

primary and which are secondary through a rule that applies to all

offenses under the Vehicle Law. More specifically, § 26-201 of

the Transportation Article establishes that an officer may issue a

citation for a violation of any Vehicle Law provision, if the officer

has probable cause to believe the person has committed or is

committing the violation. TR § 26-201(a). The General Assembly

added this provision in 1977 to make explicit a power that had

previously been implicit. 1977 Md. Laws, ch. 186; Commission to

Revise the Annotated Code, Report on S.B. 501, 1977 Leg., Reg.

Sess., at 4 (Feb. 22, 1977). Although the statute refers only to

citations and not explicitly to traffic stops, the authority to issue a

citation for a motor vehicle offense implies the authority to make a

traffic stop, because the statute requires that the citation be issued

to and acknowledged by the driver. See TR §§ 26-201(b), 26-203.

And more importantly, by authorizing an officer to issue a citation

for any motor vehicle offense without regard to whether another

offense has been committed, TR § 26-201 provides for primary

enforcement of all motor vehicle offenses. If an officer can cite a

driver for a given offense, without more, that offense is necessarily

primary. The Vehicle Law thus addresses the subject of primary

versus secondary enforcement of the motor vehicle laws by

establishing a general rule of primary enforcement.

As exceptions to that general rule, the General Assembly has

expressly designated some specific motor vehicle violations as

secondary. See, e.g., TR § 21-1104(c)(3) (driving with an object

hanging from the rearview mirror); TR § 13-411(c)(2) (driving

with a frame or border partially obscuring the license plate); see

also supra Part I.C (listing other examples). Typically, an officer

may enforce one of these provisions only after stopping a driver for

a suspected violation of a different provision. E.g., TR

§ 21-1104(c)(3)(ii). So, for example, an officer could not stop or

cite a driver who was driving with an object hanging from the

96 [108 Op. Att’y

rearview mirror but otherwise obeying the law. If the driver then

ran a red light, however, an officer could stop the driver and cite

them for both offenses. The General Assembly’s express

categorization of certain offenses as secondary confirms that the

Vehicle Law covers the subject of which motor vehicle offenses

are primary and which are secondary. Reading the Vehicle Law as

a whole, as we are required to do, e.g., 105 Opinions of the Attorney

General 3, 16 (2020), these secondary-offense provisions are best

read as exceptions to the general rule of primary enforcement

established by TR § 26-201.

Indeed, under standard principles of statutory interpretation,

the General Assembly’s establishment of these specific exceptions

indicates an intent that the general rule should apply in all cases not

expressly excepted. See, e.g., 85 Opinions of the Attorney General

80, 83 (2000) (noting that “exceptions are strictly construed”);

Leppo v. State Highway Admin., 330 Md. 416, 423 (1993) (“When

the legislature has expressly enumerated certain exceptions to a

principle, courts normally should be reluctant thereafter to create

additional exceptions.” (quoting Ferrero Constr. Co. v. Dennis

Rourke Corp., 311 Md. 560, 575 (1988)); Department of Motor

Vehicles v. Greyhound Corp., 247 Md. 662, 668 (1967) (“By

making these two items the sole exceptions, the statute is as plain

as if it had listed all of the [items] not included in the exceptions.”).

And, consistent with that understanding, where the General

Assembly has chosen to make particular offenses secondary, the

legislative history of those enactments expressly recognized that

“[e]xcept as otherwise specified, violations of the Maryland

Vehicle Law are subject to primary enforcement.” Fiscal & Policy

Note, H.B. 1335, 2017 Leg., Reg. Sess., at 1; accord Fiscal &

Policy Note, S.B. 859, 2020 Leg., Reg. Sess., at 2 (same). Thus,

read as a whole, the Vehicle Law addresses the subject of primary

versus secondary enforcement: it establishes a rule that, unless the

Vehicle Law has expressly designated a motor vehicle offense as

secondary, the offense is subject to primary enforcement.

Especially illustrative are the instances where the General

Assembly has redesignated a formerly primary offense as

secondary. 2020 Md. Laws, ch. 107 (frame or border partly

obscuring license plate); 2017 Md. Laws, ch. 756 (object hanging

from rearview mirror). In each of these cases, a major purpose of

the change was to reduce racially disparate traffic enforcement.

Hearing on H.B. 200 Before the House Env’t & Transp. Comm.,

2020 Leg., Reg. Sess., at 1:08:10-1:09:50 (Feb. 13, 2020) (“H.B.

200 Hearing”) (statement of Del. Fisher); Hearing on H.B. 1335

Before the House Env’t & Transp. Comm., 2017 Leg., Reg. Sess.,

Gen. 81] 97

at 2:29:40-2:30:30 (Mar. 9, 2017) (“H.B. 1335 Hearing”)

(statement of Del. Wilkins). But, in each case, the Legislature

chose to establish secondary enforcement for only some of the

conduct the provision covered and keep primary enforcement for

the rest. As to license plates, for instance, the Legislature provided

secondary offense status only for objects obscuring the frame or

border of a license plate and left primary enforcement in place for

material covering the actual plate number. See 2020 Md. Laws, ch.

107. Similarly, as to windshield obstruction, the General Assembly

downgraded driving with material hanging from the rearview

mirror to a secondary offense, while retaining primary enforcement

for other instances where an object obstructs a driver’s view

through the windshield. See 2017 Md. Laws, ch. 756.

In other instances, legislative proposals to make particular

offenses secondary have failed. For example, when the General

Assembly in 2009 passed legislation to prohibit texting while

driving, see 2009 Md. Laws, ch. 194 (enacting TR § 21-1124.1),

the Senate rejected a proposed floor amendment that would have

made texting while driving a secondary offense, see Amend. No.

463122/1, S.B. 98, 2009 Leg., Reg. Sess., with the understanding

that if the amendment were rejected the offense would be primary,

see Senate Floor Proceedings No. 43, 2009 Leg., Reg. Sess., at

23:00-23:48 (Mar. 13, 2009) (statement of Sen. Zirkin). This

further supports the view that the Vehicle Law establishes a general

rule of primary enforcement for motor vehicle offenses and that

preservation of that general rule, for offenses not explicitly

declared secondary, is intentional on the part of the Legislature.

Balancing the benefits and costs of secondary enforcement for a

given offense is a policy judgment, and the Vehicle Law’s express

preemption provision reserves that policy judgment to the General

Assembly.

Perhaps if the Vehicle Law only designated certain offenses

as secondary, and was otherwise silent as to how the traffic laws

are to be enforced, the case for preemption would be weaker. But

the combination of the general rule allowing police officers to cite

drivers for any Vehicle Law offense—which indicates that such

offenses are generally subject to primary enforcement—and the

specific exemptions for situations where the Legislature has

determined secondary enforcement to be appropriate, causes us to

conclude that the Maryland Vehicle Law covers the subject of

primary versus secondary enforcement of motor vehicle offenses.

Thus, a local law may not address that subject absent express

authorization by the General Assembly.

98 [108 Op. Att’y

2. Express Authorization by Other State Law

The third question under the Vehicle Law’s express

preemption provision is whether, even if the STEP Act’s

secondary-offense provisions involve a subject covered by the

Vehicle Law, there is nonetheless a separate express authorization

for local governments to legislate on that subject. The Vehicle Law

does, alongside its broad preemption provision, expressly reserve

certain powers to localities. TR § 25-102(a). We thus need to

consider whether any of those powers would authorize the STEP

Act’s secondary-offense provisions.

The list of enumerated local powers in § 25-102(a) dates back

to 1943. Before that year, the Vehicle Law had contained—

alongside the general preemption provision enacted in 1927—a

provision authorizing local governments to promulgate

“reasonable traffic regulations.” Md. Ann. Code, Art. 56, § 145

(1939). As part of its 1943 revision to the Vehicle Law, which

sought to “promot[e] greater uniformity,” 1942 Report at 8, the

General Assembly repealed that broad power. See 1943 Md. Laws,

ch. 1007. In its place, the Legislature enacted a list of six specific

local powers (copied almost verbatim from the 1938 Uniform

Vehicle Code) and provided that the Vehicle Law “shall not be

deemed to prevent local authorities” from exercising those powers.

Compare 1943 Md. Laws, ch. 1007 (enacting Art. 66 ½, § 135),

with Uniform Vehicle Code, Uniform Act Regulating Traffic on

Highways § 28, at 5 (1938 rev.).13

One of the reserved powers is “regulating or prohibiting the

stopping, standing, or parking of vehicles.” TR § 25-102(a)(1)

(emphasis added). On its face, this provision might appear to cover

traffic “stops” by police. But “stop” is a defined term under the

13

The six local powers enumerated in 1943 were: “(1) Regulating the

standing or parking of vehicles; (2) Regulating traffic by means of police

officers or traffic control devices; (3) Regulating or prohibiting

processions or assemblages on the highways; (4) Designating particular

highways as one way highways and requiring that all vehicles thereon be

moved in one specific direction; (5) Regulating the speed and weight of

vehicles in public parks; (6) Designating any intersection as a stop

intersection requiring all vehicles to stop at one or more entrances to such

intersections.” 1943 Md. Laws, ch. 1007 (enacting Art. 66 ½, § 135).

These provisions are now codified, with minimal changes, at TR

§ 25-102(a)(1)-(6). The General Assembly has since added further items

to the list, but the new items are not substantially different in character

from the original six; all essentially relate to the control of traffic on

roads under the local government’s jurisdiction. See TR § 25-102(a).

Gen. 81] 99

Vehicle Law, TR § 11-162, and when used in a “prohibitory

sense”—the sense in which § 25-102(a)(1) uses it—the term “stop”

excludes instances where a vehicle stops “in compliance with the

directions of a police officer,” TR § 11-162(2). Also, the context

in which the word “stopping” is used in § 25-102(a)(1)—together

with “standing” and “parking”—implies that the provision is

concerned with where and when a driver may stop or park their

vehicle safely, not with officer-initiated traffic stops. See Shivers

v. State, 256 Md. App. 639, 664 (2023) (noting that in statutory

interpretation “the meaning of a word is or may be known from the

accompanying words” (quoting Emmert v. Hearn, 309 Md. 19, 25

(1987)).

The provision’s history accords with that understanding.

Section 25-102(a)(1) originally omitted the word “stopping,” even

though that word had appeared in the Uniform Vehicle Code

provision on which the Maryland provision was modeled.

Compare 1970 Md. Laws, ch. 534 (enacting Art. 66 ½,

§ 15-102(a)(1)), with Uniform Vehicle Code § 15-102(a)(1), at 230

(1968 rev.). The word “stopping” was added seven years later

during the code revision process to correct this “oversight.” 1977

Md. Laws, ch. 14 (Revisor’s Note to TR § 25-102). Because the

code revision process generally is not intended to make substantive

changes to the law, this history implies that the General Assembly

did not see the addition of “stopping” alongside “standing” and

“parking” as changing the scope of the power. See, e.g.,

Comptroller v. Blanton, 390 Md. 528, 538-39 (2006).

Local governments also have the power of “[r]egulating

traffic by means of police officers or traffic control devices.” TR

§ 25-102(a)(2). This provision, in our view, recognizes that local

governments may employ police officers to direct traffic and

control the movement of vehicles on the roadway, as necessary to

ensure safe and efficient traffic flow. But we do not think it

empowers local authorities to revise the General Assembly’s

determination on whether a traffic offense is primary or secondary.

To begin, we note that the provision speaks of “regulating

traffic.” “Traffic” means the physical movement of vehicles on a

highway. See TR § 11-166. So “regulating traffic” most naturally

means directing traffic, i.e., controlling the movement of vehicles

and traffic flow. The provision recognizes that local governments

may regulate traffic in two ways—“by means of” either police

officers or traffic control devices, TR § 25-102(a)(2), with the latter

referring to traffic lights, stop signs, and the like, TR § 11-167.

This, again, suggests that § 25-102(a)(2) contemplates police

100 [108 Op. Att’y

officers acting in a role similar to a traffic light or stop sign—

directing traffic in the ordinary course of its movement. The other

provisions enacted alongside § 25-102(a)(2) in 1943 similarly

relate to the control of physical traffic movement, akin to the

placement of traffic signals, such as designation of a street as a one-

way street or of an intersection as a four-way stop. See 1943 Md.

Laws, ch. 1007. As Maryland courts often say, “the meaning of the

plainest language is controlled by the context in which it appears.”

E.g., Elsberry v. Stanley Martin Cos., 482 Md. 159, 181 (2022)

(quoting Building Materials Corp. of Am. v. Board of Educ., 428

Md. 572, 585 (2012)). Here, the context indicates that

§ 25-102(a)(2)’s reference to “regulating traffic by means of police

officers” addresses what it seems, at first glance, to address—local

authority to have police officers control and direct traffic

movement.

But even if § 25-102(a)(2)’s coverage is broader than just that,

we cannot identify a reading of that provision that is both broad

enough to encompass the authority to redesignate primary offenses

as secondary and also consistent with the provision’s text, context,

and history. That is, we doubt that the General Assembly intended

to enable localities to alter the legislative judgment that “[e]xcept

as otherwise specified, violations of the Maryland Vehicle Law are

subject to primary enforcement.” E.g., Fiscal & Policy Note, H.B.

1335, 2017 Leg., Reg. Sess. at 1. A police officer’s statutory

authorization to issue a citation for any Maryland Vehicle Law

offense, except those explicitly designated as secondary offenses

by the General Assembly, reflects that general rule of primary

enforcement. See TR § 26-201. Again, we interpret statutory

schemes, as far as possible, to form a harmonious whole. E.g.,

Lockshin v. Semsker, 412 Md. 257, 276 (2010). For example, in a

prior opinion, we concluded that even though local governments

have the express authority to regulate parking, they cannot adopt

procedures for handling parking violations that differ from the

procedure in State law. 78 Opinions of the Attorney General 263,

264-65 (1993). Here, too, we think the exercise of any power under

§ 25-102(a)(2) must be consistent with the overall statutory scheme

of the Vehicle Law.14

14

Our reading of § 25-102(a)(2) is also consistent with the principle

that a statute should be construed so that none of its language “is

rendered surplusage, superfluous, meaningless, or nugatory.” E.g., Rowe

v. Maryland Comm’n on Civil Rights, 483 Md. 329, 342 (2023) (quoting

Mayor & Town Council of Oakland v. Mayor & Town Council of

Mountain Lake Park, 392 Md. 301, 316 (2006)). In particular,

§ 25-102(a)(1) and § 25-102(a)(2) address distinct topics under our

Gen. 81] 101

Authority from other jurisdictions supports our view as well.

As noted above, § 25-102(a)(2)’s language comes from the

Uniform Vehicle Code. Other states have interpreted their parallel

provisions consistent with our view that § 25-102(a)(2) authorizes

localities to use police to regulate the movement of traffic in

accordance with law but not to alter the rules of traffic enforcement

themselves. For example, the Minnesota Supreme Court held that

the effect of a provision with near-identical language “is only to

authorize a city to direct the movement of vehicles on the

roadway.” State v. Kuhlman, 729 N.W.2d 577, 582 (Minn. 2007);

see also id. at 582-84 (holding that state law preempted city attempt

to authorize red light cameras). Similarly, the Florida Supreme

Court in Masone v. City of Aventura, 147 So.3d 492, 497 (Fla.

2014), concluded that the purpose of its own parallel statutory

language was to allow local governments to control the movement

of traffic but not to alter the statutory rules of traffic enforcement.

In contrast, we know of no jurisdiction that has interpreted this

provision to authorize a locality to redesignate a primary traffic

violation as secondary.

3. The Role of Enforcement Discretion

One might argue that our conclusion clashes with the

enforcement discretion normally vested in police departments and,

interpretation: § 25-102(a)(1) covers rules for where drivers can stop or

park their vehicles, and § 25-102(a)(2) deals with the control of active

traffic flow by official authority, namely officers or traffic signals. One

might also argue that, unless § 25-102(a)(2) authorizes some subject

matter that would otherwise be preempted, § 25-102(a)(2) serves no

purpose. But the provisions of § 25-102(a) may have been intended

primarily for the avoidance of doubt, that is, to eliminate any suggestion

that the listed subjects are preempted. Indeed, § 25-102(a) seems to

cover at least some matters that would not have been preempted even

absent § 25-102(a)’s enactment. For example, § 25-102(a)(12)

authorizes localities to “[a]dopt[] any other traffic regulations as

specifically authorized in the Maryland Vehicle Law,” which (because it

merely refers to authorization granted elsewhere) would necessarily be

surplusage under a strict application of the canon. Finally, it is an equally

well-established rule of statutory interpretation that interpreters should

neither “add nor delete language so as to reflect an intent not evidenced

in the plain and unambiguous language of the statute,” nor should they

“construe a statute with forced or subtle interpretations that limit or

extend its application.” E.g., Rowe, 483 Md. at 342 (quoting Lockshin,

412 Md. at 275). As we have explained, § 25-102(a)(2) speaks only to

“regulating traffic,” and we think it would require a “forced”

interpretation to stretch that language to encompass the designation of

traffic violations as primary or secondary.

102 [108 Op. Att’y

thus, in the local governments that employ those police

departments. No police department enforces all of the traffic laws

all of the time—as anybody who has driven on a highway knows

from observing that the speed of traffic is usually five or ten miles

per hour above the speed limit. Generally, the decision whether to

stop or detain a driver for a motor vehicle offense is a matter of the

individual officer’s discretion, even when the officer has observed

a probable violation. See Ashburn v. Anne Arundel County, 306

Md. 617, 624 (1986). Indeed, current departmental policy of the

MCPD explicitly grants officers “discretion in the enforcement of

traffic laws” and states that “[a] written warning is appropriate . . .

where a minor equipment defect is apparent.” MCPD, FC No.

1000, Traffic Management System, § VIII(A)-(B) (July 1, 2022).

It also seems clear that a local government generally has

authority to set internal operating rules for its own agencies,

including the local police department. “The authority to establish

a police force would be futile if it did not carry with it, at least by

implication, the authority to enact reasonable rules for the effective

administration of the force . . . .” 16A McQuillin: The Law of

Municipal Corporations § 45:14 (3d ed., June 2023 update). The

question arises, then, why a local legislative body cannot adopt

something akin to the STEP Act as a way of setting rules for the

exercise of enforcement discretion for its own local police

department.

It may well be that, as a general matter, the County Council

could by ordinance set enforcement priorities for the county police

department. But whatever legislative authority the County Council

might possess is overridden in this specific area by the General

Assembly’s decision to preempt “local law[s]” and “ordinance[s]”

addressing “subject[s]” covered by the Vehicle Law. TR

§ 25-101.1(b)(3). In this particular area of motor vehicle law—that

is, whether an offense is primary or secondary—the Legislature has

decided as a policy matter that the need for statewide uniformity

outweighs local governments’ legislative autonomy. See 65

Opinions of the Attorney General at 486. Simply put, then, the

County Council may not legislate on a subject the General

Assembly has fenced off, even when it would have full power to

act but for the preemption statute. See 101 Opinions of the Attorney

General at 55-57 (concluding that preemption limits a county

governing body’s power to place conditions on appropriations in

the context of public library funding).

We also express no opinion about whether the county police

department could adopt, on its own authority, an internal policy

Gen. 81] 103

resembling the STEP Act. The MCPD currently has internal

policies, issued by the Chief of Police, on a variety of subjects. See

generally MCPD, Department Policies, https://www.montgomery

countymd.gov/pol/resource/policies.html (last visited Sept. 13,

2023). Express preemption under TR § 25-101.1 applies only to a

“local law, ordinance, or regulation,” and there is at least a question

as to whether an executive branch agency’s internal policy, which

is subject to change at any time and merely communicates how the

agency plans to exercise its discretion, would qualify as a local law,

ordinance, or regulation, especially when the policy might not need

to be promulgated as a formal regulation under the applicable

administrative procedure statute. Cf. Montgomery County Code

§ 35-3(c) (indicating that county administrative procedure law

governs the adoption of police “regulations” but not “orders”). In

any event, we need not decide whether a police department could

adopt such a policy to answer the question that you have asked. We

conclude only that a local legislative body may not designate a

traffic offense as secondary when State law has not done so.15

C. The STEP Act’s Consent-Search Provision

The STEP Act would also prohibit an MCPD officer from

requesting consent to search, during a traffic stop, unless

reasonable suspicion or probable cause “arises during the stop.”

STEP Act (proposed § 35-27(e)(2)). For the reasons explained

below, the Vehicle Law’s express preemption provision would not

cover this aspect of the STEP Act, because the Vehicle Law does

not address the conditions under which an officer may search a

vehicle, or its occupants, during a traffic stop. Nor does the

Vehicle Law establish implied field preemption beyond the scope

of its express preemption clause. And a restriction on searches

during stops would not conflict with any provision of the Vehicle

Law. Accordingly, the Vehicle Law would not preempt the STEP

Act’s consent-search provision.16

15

Because we conclude that the STEP Act’s secondary-offense

provisions would be expressly preempted, we need not consider whether

they would be subject to implied or conflict preemption.

16

Your opinion request asked only whether the Vehicle Law would

preempt the STEP Act. We thus limit our preemption analysis to the

Vehicle Law. We also note that the STEP Act’s provision precluding

collective bargaining on the matters covered by the STEP Act (proposed

§ 33-80) would not be preempted by the Vehicle Law for similar reasons

to those discussed here: the Vehicle Law does not address collective

bargaining or require collective bargaining on any particular topic, so no

form of preemption would apply.

104 [108 Op. Att’y

1. Express Preemption

As we have explained, express preemption under the Vehicle

Law applies only when a local law, ordinance, or regulation

addresses a “subject covered by the Maryland Vehicle Law.” TR

§ 25-101.1(b)(3). Although the Vehicle Law’s enforcement

provisions cover procedures for citation, arrest, and prosecution for

motor vehicle offenses, see generally TR §§ 26-201 to 26-412,

nothing in the Vehicle Law prescribes the circumstances under

which an officer may, or may not, conduct a search during a traffic

stop or otherwise. In short, the Vehicle Law is not the source of an

officer’s authority to search.17 Thus, the Vehicle Law does not

expressly preempt a local law limiting a local police department’s

authority to conduct searches, because searches are “altogether

beyond the purview of the Vehicle Law.” See 71 Opinions of the

Attorney General 400, 404 (1986) (concluding that the Vehicle

Law does not address speed bumps).

2. Implied Preemption

Implied preemption occurs when the “General Assembly has

acted with such force that an intent to occupy the entire field must

be implied.” Perennial Solar, 464 Md. at 619. But we do not think

the Vehicle Law implicitly preempts a field broader than its express

preemption provision. In other words, if a local law is not subject

to the Vehicle Law’s express preemption provision, it is likely not

subject to implied preemption either. Normally, when the General

Assembly specifies the items to which a law will apply, we will

infer that the exclusion of other items was intentional. See 98

Opinions of the Attorney General 3, 12 (2013) (discussing the

canon of construction expressio unius est exclusio alterius, or “the

expression of one thing is the exclusion of another”). That

principle applies to preemption as well. When the General

Assembly has drafted an express preemption provision, it is usually

a reasonable inference that the Legislature considered the breadth

of the field it wanted to preempt and that the express preemption

provision corresponds to that intent. See Browning-Ferris, 292

Md. at 153 (holding that the enactment of a narrower express

preemption provision overrode what had been “a very strong case”

for broader implied preemption). Although we do not foreclose the

possibility that legislative intent could indicate implied preemption

extending beyond the bounds of express preemption within the

17

TR § 25-113 requires law enforcement agencies to gather certain

data on searches during traffic stops and to adopt a policy against race-

based traffic stops that does not affect an officer’s otherwise existing

authority to search, but it does not, itself, grant authority to search.

Gen. 81] 105

context of a particular statutory scheme, we see no evidence of such

an intent here. The Vehicle Law therefore would not implicitly

preempt the STEP Act’s consent-search provision.

3. Conflict Preemption

Conflict preemption is the third and final form of preemption

Maryland law recognizes. The first type of conflict preemption,

and the one Maryland courts most frequently consider, is “verbal”

or “prohibit-permit” conflict. Under this type of conflict

preemption, local law may not permit what State law prohibits, nor

may local law prohibit what State law affirmatively permits. See

Mayor & City Council of Baltimore v. Sitnick, 254 Md. 303, 317

(1969). There is no preemption if State law permits something

simply by not addressing it; rather, State law must affirmatively

authorize an activity before a local law prohibiting that activity will

be preempted. Coalition for Open Doors v. Annapolis Lodge No.

622, Benevolent & Protective Order of Elks, 333 Md. 359, 380

(1994). As we have discussed, the Vehicle Law is silent on

searches; it neither prohibits them, nor expressly permits

them. Accordingly, there would be no verbal conflict between the

Vehicle Law and a local prohibition on consent searches.

The second type of conflict preemption is “functional

conflict.” The courts have not been as clear about what a functional

conflict involves. But, “[i]n general, some element of

irreconcilability or legal inconsistency is required, such that both

the State and local laws cannot be applied together.” 93 Opinions

of the Attorney General at 135. We see no inconsistency or

irreconcilability between the Vehicle Law and the STEP Act’s

consent-search provisions.

The consent-search provision would not create a problem

analogous to any of the situations where courts have found

functional conflicts. See Coalition for Open Doors, 333 Md. at 380

n.39 (citing functional conflict cases). First, the consent-search

provision would not create a situation where there would be

conflicting rules in the same area such that a police officer could

not simultaneously comply with State and local law. See

Montgomery County v. Board of Supervisors of Elections, 311 Md.

512, 517 (1988) (finding functional conflict when State and local

law provided irreconcilable methods of appointing the same

officers). The provision also would not prohibit a local

government from taking action that is required under State law. See

East v. Gilchrist, 296 Md. 368, 373-74 (1983) (finding functional

conflict where local charter prohibited county from spending

106 [108 Op. Att’y

money that State law required it to spend). Nor would it create a

“direct conflict with a State statute regulating the same matter,”

Worton Creek, 381 Md. at 514 (discussing Montgomery County Bd.

of Realtors v. Montgomery County, 287 Md. 101, 109-10 (1980),

in which the Court held that a local tax conflicted with the State’s

scheme for assessment of real property), because, again, the

Vehicle Law does not regulate searches.

We have also suggested that a functional conflict may exist

when a local law interferes with the functioning of a State law. See

98 Opinions of the Attorney General at 91. We would be cautious

about finding a functional conflict on this basis alone, given that

Maryland courts have repeatedly declined to adopt the similar

federal doctrine of obstacle preemption, under which a law is

preempted if it frustrates the purpose of a federal statute. E.g.,

Chaney, 454 Md. at 541 n.19. But even assuming State law can

preempt local law in this way as a general matter, this is not such a

case.

The purpose of the Vehicle Law is to ensure the safe and

efficient movement of traffic, and to prevent crashes and injuries

on roadways. Supra Part I.B. By contrast, the functional effect of

the consent-search provision of the STEP Act is to limit an officer’s

authority to search an already-stopped vehicle. Because these

provisions of the Act would only limit what an officer can do once

the vehicle has already been stopped, their impact on traffic

enforcement would be minimal—given that traffic violations are

meant to be observable before the vehicle has been stopped. When

an officer seeks consent to search a stopped vehicle, despite lacking

any particularized suspicion of a crime, their purpose is usually not

to enforce the traffic laws but to search for evidence of other

crimes, like possession of contraband. See, e.g., LaFave, supra, at

1891-92. Perhaps there might be some circumstances where

evidence of a motor vehicle offense could only be revealed through

a suspicionless consent search, but we think such cases will be

rare. The STEP Act’s consent-search provision thus would not

interfere with the Vehicle Law’s functioning to such a degree as to

be preempted.

III

Conclusion

In our opinion, the Maryland Vehicle Law would preempt a

local law, such as the STEP Act, that would designate a violation

of the Vehicle Law as secondary when State law has not designated

it as such. This is because the determination of which motor

Gen. 81] 107

vehicle offenses are primary, and which are secondary, is a subject

covered by the Vehicle Law. And neither the local power to

regulate “stopping, standing or parking,” TR § 25-102(a)(1), nor

the local power to “regulate traffic by means of police officers,”

TR § 25-102(a)(2), authorizes a local government to redesignate a

Vehicle Law offense from primary to secondary status. On the

other hand, the Vehicle Law would not preempt a local law limiting

a local police officer’s ability to request consent to search during

traffic stops. Because the Vehicle Law does not address the

conditions under which searches are permissible, such a local law

would neither intrude on a subject covered by the Vehicle Law nor

conflict with the Vehicle Law.

Anthony G. Brown

Attorney General of Maryland

Thomas S. Chapman

Assistant Attorney General

Patrick B. Hughes

Chief Counsel, Opinions and Advice