Massachusetts Car Idling Laws: Public Ways Only

Q: Which Massachusetts law actually covers this?

M.G.L. c. 90, § 13, “Safety precautions for proper operation and parking of vehicles and buses”, in the Massachusetts vehicle code. It is a theft provision rather than an environmental one, which is why a search for an idling law does not return it. The operative sentence is quoted on this page and links to the Massachusetts General Court page it was read from.

Q: Does it matter whether the car was locked in Massachusetts?

Not to whether the section applies. Nothing in the Massachusetts section makes the offence depend on whether the car was locked or the key taken out, which separates it from the 9 states where that is exactly what it depends on. What M.G.L. c. 90, § 13 requires is set out in its own words above.

Q: Can you leave a car running in your own driveway in Massachusetts?

The Massachusetts chapter that carries this section applies to ways as that word is defined in the statute, and the sentence doing that is quoted on this page. A driveway is not what that sentence describes. What can still reach a car standing on private ground is a city ordinance, and those are set by the city rather than by the state.

Q: What does Massachusetts charge for it?

Massachusetts prints no penalty inside the section, which is the commoner pattern: a violation falls to the chapter's general penalty provision. 18 states of the 34 print one where a reader would find it. The states that do print one are collected on the national page with the wording each of them uses.

Q: How current is this?

Every line was read on September 23, 2026, off the state's own published code, and links back to the section it came from. Legislatures amend these between sessions and a repeal leaves the old text in circulation for years afterwards, so the link beside each quote is what governs on the day.

Prohibited

Leaving it running unattended

M.G.L. c. 90, § 13

No

Whether the lock matters

9 states of the 34 are built on it

Public ways

How far the chapter reaches

one of 20 confined to a road

in excess of five minutes

Separate idling limit

M.G.L. c. 90, § 16A

September 23, 2026

Read

off the state’s own code

The short answer

Massachusetts prohibits it, and the chapter reaches public ways only.

Massachusetts prohibits it on a way, and defines a way as a public road or one laid out under statute. So the section and its reach are two separate readings: the prohibition is in one place and the sentence that confines it to a public way is in another, and 20 states are built that way. Both are set out below in their own words.

A reader looking at the section alone would not see this. What confines it to a public way sits in the scope provision at the front of the chapter, reproduced below, and 20 states put it there.

Public waysM.G.L. c. 90, § 13A separate idling limit at M.G.L. c. 90, § 16A

The section itself

M.G.L. c. 90, § 13, and the sentence it turns on

This is a theft provision rather than an environmental one, which is why a search for a Massachusetts idling law does not return it and why so much of what is written about it is written about a different statute. It sits in the vehicle code with the rules about stopping and standing, and it was put there to stop cars being driven away by somebody who did not own them.

The operative sentence is reproduced below rather than summarised, because everything that separates one state from the next in this reading sits inside it. The card carries the citation, the title the code gives the section, and the link the sentence was read from.

M.G.L. c. 90, § 13

Public ways

Safety precautions for proper operation and parking of vehicles and buses

No person having control or charge of a motor vehicle, except a person having control or charge of a police, fire or other emergency vehicle in the course of responding to an emergency or a person having control or charge of a motor vehicle while engaged in the delivery or acceptance of goods, wares or merchandise for which the vehicle's engine power is necessary for the loading or unloading of such goods, wares or merchandise, shall allow such vehicle to stand in any way and remain unattended without stopping the engine of said vehicle, effectively setting the brakes thereof or making it fast, and locking and removing the key from the locking device and from the vehicle.

The sentence that decides where it reaches

''Way'', any public highway, private way laid out under authority of statute, way dedicated to public use, or way under the control of park commissioners or body having like powers.

What it turns on Prohibited, but the statute reaches a public way only
Exemptions written in 2

General Laws Part I, Title XIV, Chapter 90, Section 13, Massachusetts General Court, read September 23, 2026

Where the duty stops

The Massachusetts chapter reaches public ways and stops there

A reader looking at the section alone would not see this. What confines it to a public way sits in the scope provision at the front of the chapter, reproduced below, and 20 states put it there.

This is the reading a driveway question comes down to, and it is two documents rather than one: the section that prohibits the thing and, at the front of the chapter, the sentence that says what the chapter applies to. Both are reproduced here. A city ordinance can still reach private ground, and that is a municipal question rather than a state one.

A two storey house behind a long concrete driveway with two cars parked up by the garage doors, a public footway crossing the foreground, and a thin dusting of snow over everything — Twenty of these sections sit in a chapter that reaches only a highway or a public way. The line those chapters turn on runs across the bottom of this frame, and it is nowhere in the section a reader would have found. “A dusting of snow on the front of a house and driveway along Aqueteong Lane, Ewing Township, Mercer County, New Jersey”, Famartin, CC BY-SA 4.0

What the rule lets through

The 2 exemptions written into the Massachusetts section

Two exemptions are written into the Massachusetts section, each quoted below from the sentence that creates it. An exemption narrows the rule it sits in, which makes it load bearing in exactly the way that rule is, so none of them is paraphrased.

emergency vehicles responding, and vehicles whose engine power is loading or unloading goods
except a person having control or charge of a police, fire or other emergency vehicle in the course of responding to an emergency or a person having control or charge of a motor vehicle while engaged in the delivery or acceptance of goods, wares or merchandise for which the vehicle's engine power is necessary for the loading or unloading of such goods, wares or merchandise
the sentence that creates it, read September 23, 2026
vehicles being serviced, and engine driven loading, are outside the five minute idling cap
This section shall not apply to (a) vehicles being serviced, provided that operation of the engine is essential to the proper repair thereof, or (b) vehicles engaged in the delivery or acceptance of goods, wares, or merchandise for which engine assisted power is necessary and substitute alternate means cannot be made available
the sentence that creates it, read September 23, 2026

The other law entirely

Massachusetts also runs an emissions idling limit

Massachusetts does run an emissions idling limit, one of 16 states that do. It is in excess of five minutes for the engine of any stopped motor vehicle. It runs alongside the unattended vehicle section above and not instead of it: different chapter, different scope, different penalty.

The two are kept apart on this page for the same reason they are apart in the books. An unattended vehicle section sits in the vehicle code and exists to stop a car being taken. An idling limit is an air quality regulation, written by an environmental agency, aimed mostly at buses and at trucks above a weight, and enforced by somebody else. Only 16 states publish one at all, and 2 of those name the regulation without putting a figure where a reader can reach it.

in excess of five minutes

Emissions regulation

What it covers the engine of any stopped motor vehicle
Citation M.G.L. c. 90, § 16A

No person shall cause, suffer, allow or permit the unnecessary operation of the engine of a motor vehicle while said vehicle is stopped for a foreseeable period of time in excess of five minutes.

M.G.L. c. 90, § 16A, read September 23, 2026

A low angle view inside an inspection garage, a car raised on a lift with a sampling hose run into its tailpipe, and an inspector standing in silhouette against the window watching it — The other law on these pages. An idling limit is an air quality regulation, written by an environment department, measured in minutes of engine running, and it is what most searches about this return. “Car being checked at an auto emission inspection station in Norwood, Ohio (DOCUMERICA, NARA 557848)”, Lyntha Scott Eiler for the U.S. Environmental Protection Agency, Public Domain

How Massachusetts compares

The same question in the other forty nine

34 states prohibit leaving a car running unattended and 16 have no section for it. Of the 34, 9 turn on whether the car was left unsecured, 20 sit in a chapter that reaches a road and nothing else, and 5 apply wherever the car is standing.

The bar splits the fifty by what their section does, and the table beneath it puts the strictest reading first, which is not the order a reader would guess from a map of how cold it gets.

5Always

9If unlocked

17Highways

3Public ways

16No section

Fifty state vehicle codes read September 23, 2026, strictest reading first.
State	What the section does	Citation	Turns on the lock	Separate idling limit
Kentucky	AlwaysProhibited wherever the car is standing	KRS 189.430	No	No
Louisiana	AlwaysProhibited wherever the car is standing	La. R.S. 32:145	No	No
Nevada	AlwaysProhibited wherever the car is standing	NRS 484B.530	No	No
Utah	AlwaysProhibited wherever the car is standing	Utah Code 41-6a-1403	No	No
Vermont	AlwaysProhibited wherever the car is standing	23 V.S.A. § 1111	No	Yes
Colorado	If unlockedOnly where the car was left unlocked or the key left in it	C.R.S. 42-4-1206	Yes	No
Florida	If unlockedOnly where the car was left unlocked or the key left in it	Fla. Stat. § 316.1975	Yes	No
Idaho	If unlockedOnly where the car was left unlocked or the key left in it	Idaho Code 49-602	Yes	No
Illinois	If unlockedOnly where the car was left unlocked or the key left in it	625 ILCS 5/11-1401	Yes	Yes
Kansas	If unlockedOnly where the car was left unlocked or the key left in it	K.S.A. 8-1573	Yes	No
Maryland	If unlockedOnly where the car was left unlocked or the key left in it	Md. Code Ann., Transp. 21-1101	Yes	Yes
New Hampshire	If unlockedOnly where the car was left unlocked or the key left in it	RSA 265:72	Yes	Yes
Ohio	If unlockedOnly where the car was left unlocked or the key left in it	Ohio Rev. Code 4511.661	Yes	No
Texas	If unlockedOnly where the car was left unlocked or the key left in it	Tex. Transp. Code Sec. 545.404	Yes	Yes
Alabama	HighwaysProhibited, but the chapter reaches highways only	Ala. Code Section 32-5A-50	No	No
Alaska	HighwaysProhibited, but the chapter reaches highways only	13 AAC 02.480	No	No
California	HighwaysProhibited, but the chapter reaches highways only	Cal. Veh. Code 22515	No	Yes
Delaware	HighwaysProhibited, but the chapter reaches highways only	21 Del. C. § 4182	No	Yes
Hawaii	HighwaysProhibited, but the chapter reaches highways only	HRS 291C-121	No	No
Michigan	HighwaysProhibited, but the chapter reaches highways only	Mich. Comp. Laws 257.676	No	No
Mississippi	HighwaysProhibited, but the chapter reaches highways only	Miss. Code Ann. 63-3-909	No	No
Nebraska	HighwaysProhibited, but the chapter reaches highways only	Neb. Rev. Stat. 60-6,168	No	No
New Jersey	HighwaysProhibited, but the chapter reaches highways only	N.J.S.A. 39:4-137	No	Yes
New Mexico	HighwaysProhibited, but the chapter reaches highways only	NMSA 1978, Section 66-7-353	No	No
New York	HighwaysProhibited, but the chapter reaches highways only	N.Y. Vehicle and Traffic Law § 1210	No	Yes
Oklahoma	HighwaysProhibited, but the chapter reaches highways only	47 O.S. 11-1101	No	No
Oregon	HighwaysProhibited, but the chapter reaches highways only	ORS 811.585	No	Yes
Pennsylvania	HighwaysProhibited, but the chapter reaches highways only	75 Pa.C.S. § 3701	No	Yes
South Carolina	HighwaysProhibited, but the chapter reaches highways only	S.C. Code Ann. SECTION 56-5-2570	No	No
Tennessee	HighwaysProhibited, but the chapter reaches highways only	Tenn. Code Ann. 55-8-162	No	No
Washington	HighwaysProhibited, but the chapter reaches highways only	RCW 46.61.600	No	No
Massachusetts	Public waysProhibited, but the statute reaches a public way only	M.G.L. c. 90, § 13	No	Yes
North Carolina	Public waysProhibited, but the statute reaches a public way only	N.C.G.S. § 20-163	No	No
Rhode Island	Public waysProhibited, but the statute reaches a public way only	R.I. Gen. Laws § 31-22-1	No	Yes
Arizona	No sectionNo unattended vehicle section in the code	No section	No	No
Arkansas	No sectionNo unattended vehicle section in the code	No section	No	No
Connecticut	No sectionNo unattended vehicle section in the code	No section	No	Yes
Georgia	No sectionNo unattended vehicle section in the code	No section	No	No
Indiana	No sectionNo unattended vehicle section in the code	No section	No	No
Iowa	No sectionNo unattended vehicle section in the code	Iowa Code 321.362	No	No
Maine	No sectionNo unattended vehicle section in the code	No section	No	Yes
Minnesota	No sectionNo unattended vehicle section in the code	No section	No	No
Missouri	No sectionNo unattended vehicle section in the code	No section	No	No
Montana	No sectionNo unattended vehicle section in the code	Mont. Code Ann. 61-8-357	No	No
North Dakota	No sectionNo unattended vehicle section in the code	No section	No	No
South Dakota	No sectionNo unattended vehicle section in the code	SDCL 32-30-5	No	No
Virginia	No sectionNo unattended vehicle section in the code	No section	No	Yes
West Virginia	No sectionNo unattended vehicle section in the code	No section	No	No
Wisconsin	No sectionNo unattended vehicle section in the code	No section	No	No
Wyoming	No sectionNo unattended vehicle section in the code	W.S. 31-5-509	No	No

Massachusetts car idling questions

Is it illegal to leave your car running unattended in Massachusetts?

Massachusetts prohibits it on a way, and defines a way as a public road or one laid out under statute. So the section and its reach are two separate readings: the prohibition is in one place and the sentence that confines it to a public way is in another, and 20 states are built that way. Both are set out below in their own words. A reader looking at the section alone would not see this. What confines it to a public way sits in the scope provision at the front of the chapter, reproduced below, and 20 states put it there.

Which Massachusetts law actually covers this?

Does it matter whether the car was locked in Massachusetts?

Can you leave a car running in your own driveway in Massachusetts?

What does Massachusetts charge for it?

Does Massachusetts have an idling limit?

How current is this?

Car idling laws in every state

Massachusetts studded tire lawThe other winter driving rule a state writes and a city can change, with the dates each one sets.Massachusetts sidewalk snow rulesHow long a city gives before the walk has to be clear, quoted from the ordinance that sets it.Massachusetts frozen pipesWhat the same cold morning is doing to the building the car is parked beside.Massachusetts first snowWhen the mornings that raise this question usually start, measured against the years behind it.

Massachusetts read September 23, 2026, off the state’s own published code: M.G.L. c. 90, § 13 and the chapter it sits in, and M.G.L. c. 90, § 16A for the separate idling limit. Every quotation above is reproduced in the source’s own wording and links back to the document it was read from. Legislatures amend these between sessions and a repealed section stays in circulation for years afterwards, so the link beside a quote is what governs on the day. What Massachusetts wrote is what this page carries: the offence, the clause it turns on, how far the chapter reaches, what the legislature exempted, and the sentence it set.