Which Massachusetts Speed Limits Carry the Deadliest Crashes?

The fatal rate rises with every step up the posted limit, and the injury rate does not follow it. Across the 372,119 Massachusetts crashes from 2022 through 2024 that carry a posted speed limit, roads posted 5 to 30 miles per hour produced 1.89 fatal crashes per 1,000, roads posted 35 to 45 produced 3.29, and roads posted 50 to 65 produced 4.93. That is the fatal rate more than doubling. The share of crashes that injured somebody moves differently: 21.50 per cent on the slow roads, 25.92 per cent on the middle band, and then back down to 24.34 per cent on the fastest ones. Two measures of severity, pulled from the same records, that behave in two different ways. These figures come from the MassDOT IMPACT crash records, the same source behind this site’s Massachusetts crash report. To talk through a Massachusetts crash, call Jim Glaser Law at (617) JIM-WINS. The line is answered 24 hours a day. The first telephone consultation is offered without charge.

What Was Counted, and What Was Not

Three years of Massachusetts crash records, 2022 through 2024, return 405,240 crashes statewide. Of those, 372,119 carry a posted speed limit somewhere between 5 and 65 miles per hour, and those are the crashes this article is about.

The rest are named rather than quietly dropped. 32,169 crashes, 7.94 per cent of the total, have no posted limit recorded at all. Another 952 carry a value that cannot be a posted limit in Massachusetts: negative numbers, values of 1 through 4, an 88, and a scatter of entries running up past 100 to 665. Those are data entry rather than signage, and they are excluded.

So every percentage below is a share of the 372,119, not of the 405,240. Where a town figure appears, it is that town’s crashes in that band against that town’s total crashes including the unrecorded ones, which is the more conservative way to state it.

The Fatal Rate Climbs, Band by Band

Here is every posted limit Massachusetts actually signs, with the fatal rate expressed per 1,000 crashes so the bands can be compared to one another rather than to their own sizes.

Posted limit	Crashes	Fatal	Fatal per 1,000	Injury crashes	Injury share
5 mph	4,825	2	0.41	336	6.96%
10 mph	6,365	2	0.31	477	7.49%
15 mph	6,227	6	0.96	579	9.30%
20 mph	11,307	17	1.50	1,913	16.92%
25 mph	79,814	159	1.99	17,331	21.71%
30 mph	108,962	226	2.07	26,131	23.98%
35 mph	53,849	148	2.75	13,747	25.53%
40 mph	29,298	95	3.24	7,662	26.15%
45 mph	14,621	79	5.40	3,937	26.93%
50 mph	9,043	53	5.86	2,361	26.11%
55 mph	19,729	64	3.24	4,674	23.69%
60 mph	1,851	15	8.10	457	24.69%
65 mph	26,228	148	5.64	6,348	24.20%
All banded	372,119	1,014	2.72	85,953	23.10%

Two Massachusetts roads produce most of the volume. The 30 mile per hour band alone holds 108,962 crashes, 29.28 per cent of everything counted, and the 25 band holds another 79,814. Together those two bands are more than half of all Massachusetts crashes with a recorded limit. That is the residential and downtown street grid, and it is where the ordinary Massachusetts crash happens.

The fatal rate on those two bands is the lowest of any band above 20 miles per hour: 1.99 and 2.07 per 1,000. Step up to 45 and it is 5.40. At 60 it is 8.10, the highest figure in the table.

Answer Capsule

Across 372,119 Massachusetts crashes from 2022 through 2024 that carry a posted speed limit, the fatal rate climbs with the limit and the injury rate does not. Roads posted 5 to 30 miles per hour produced 217,500 crashes, 412 of them fatal, a rate of 1.89 per 1,000, with 21.50 per cent injuring someone. Roads posted 35 to 45 produced 97,768 crashes, 322 fatal, 3.29 per 1,000, with the injury share at its peak of 25.92 per cent. Roads posted 50 to 65 produced 56,851 crashes, 280 fatal, 4.93 per 1,000, with the injury share back down to 24.34 per cent. The sharpest split in the data is not about severity at all: bicycle and pedestrian crashes are 3.54 per cent of everything on the slow roads and 0.20 per cent on the fast ones, 7,689 against 112. Where a Massachusetts community’s crashes happen varies enormously, from Chelmsford at 43.64 per cent on roads posted 50 to 65 to Lynn at 0.07 per cent. Source: MassDOT IMPACT crash records, 2022 to 2024. Call Jim Glaser Law at (617) JIM-WINS; the first telephone consultation is offered without charge.

The Injury Rate Turns Over Where the Fatal Rate Does Not

Group the bands into three and the divergence is plain.

Band	Crashes	Fatal per 1,000	Injury share	Bicycle + pedestrian share
5 to 30 mph	217,500	1.89	21.50%	3.54%
35 to 45 mph	97,768	3.29	25.92%	1.47%
50 to 65 mph	56,851	4.93	24.34%	0.20%

The fatal rate goes 1.89, 3.29, 4.93. It never stops climbing. The injury share goes 21.50, 25.92, 24.34. It climbs into the middle band and then reverses.

This is the third distinct pattern this site has now measured in the same three years of records, and the difference between them is worth stating because it is the part that carries information. Darkness moved the fatal rate by more than four times while leaving the injury rate flat, which is set out in the Massachusetts night crash data. Snow moved both rates down together, which is in the Massachusetts road surface crash data. Posted speed does neither. It separates them and sends them in different directions above 45 miles per hour.

INFERRED, and labelled as such because the crash records do not carry the reason: the middle band is arterial road. A 35 or 40 mile per hour Massachusetts road is the one with traffic lights, left turns across oncoming traffic, curb cuts into shopping plazas, and cars entering from side streets. Those are angle and turning collisions at meaningful speed, and they injure people at the highest rate in the table. The 50 to 65 band is mostly limited access highway, where traffic moves in one direction, opposing traffic is separated by a barrier, and the common crash is a same-direction impact at a modest closing speed even though both vehicles are moving fast. Fewer of those crashes injure anyone. The ones that do go wrong, go wrong badly, which is why the fatal rate keeps rising while the injury rate does not.

The 55 Mile Per Hour Anomaly

One band breaks the pattern and it is reported rather than smoothed over.

Roads posted 55 miles per hour produced 19,729 crashes and 64 fatal crashes, a rate of 3.24 per 1,000. That is lower than 45 miles per hour (5.40), lower than 50 (5.86), and lower than 65 (5.64). It sits between two much deadlier bands on either side of it.

The 60 band is the opposite case and needs the same caution. Its 8.10 per 1,000 is the highest number in the table, and it rests on 15 fatal crashes out of 1,851, which is the smallest band above 15 miles per hour. A handful of crashes moves a rate built on a base that small, and it should not be read as firmly as the 25, 30 and 65 figures, which rest on 159, 226 and 148 fatal crashes respectively.

No explanation for the 55 result is offered here, because the records do not contain one and guessing would be worse than leaving it open. It is stated as a measured fact that does not fit the trend.

Bicycles and Pedestrians Are Almost Entirely a Slow-Road Problem

This is the largest effect in the data and it is not a severity effect at all.

Of 4,356 Massachusetts bicycle crashes in the three years, 3,148 happened on roads posted 5 to 30 miles per hour and 29 happened on roads posted 50 to 65. Of 5,980 pedestrian crashes, 4,541 were on the slow roads and 83 were on the fast ones.

Put as a share of each band’s own crashes, bicycle and pedestrian incidents are 3.54 per cent of everything on roads posted 5 to 30, 1.47 per cent in the middle band, and 0.20 per cent above 50. The gradient runs the opposite way to the fatal rate.

That has a practical consequence for anyone hurt walking or riding in Massachusetts. The crash almost certainly happened on a street posted 25 or 30 miles per hour, which is a street with a sidewalk, a crosswalk, parked cars, driveways and sightlines that buildings interrupt. The questions that decide those cases are about what could be seen and who had the right of way, and they are set out in pedestrian accident rights in Massachusetts and in the Massachusetts bicycle laws.

Where Each Community’s Crashes Actually Happen

The statewide split conceals enormous variation between Massachusetts communities, and this is where a town’s own numbers matter more than the state’s.

Among communities with at least 2,000 crashes in the three years, these carry the largest share of their crashes on roads posted 50 to 65 miles per hour.

Community	Total crashes	On roads posted 50 to 65	Share
Chelmsford	2,108	920	43.64%
Andover	3,302	1,300	39.37%
Auburn	2,247	869	38.67%
Randolph	2,606	987	37.87%
Braintree	2,536	949	37.42%
Weston	2,281	844	37.00%
Saugus	2,063	759	36.79%
Westborough	2,182	655	30.02%
Milton	2,135	635	29.74%
Woburn	3,144	764	24.30%

And these carry the smallest share.

Community	Total crashes	On roads posted 50 to 65	Share	On roads posted 5 to 30
Lynn	6,074	4	0.07%	5,629 (92.67%)
Pittsfield	2,809	3	0.11%	1,812 (64.51%)
Cambridge	4,774	14	0.29%	4,315 (90.39%)
Malden	2,791	44	1.58%	2,654 (95.09%)
Chelsea	2,920	94	3.22%	2,446 (83.77%)
Lawrence	5,385	224	4.16%	5,032 (93.44%)
Lowell	7,781	368	4.73%	4,442 (57.09%)
Fitchburg	3,424	182	5.32%	2,812 (82.13%)

Chelmsford and Lynn are 30 miles apart and are, in this respect, two different states. 43.64 per cent of Chelmsford’s crashes are on high-speed road, against 0.07 per cent of Lynn’s. The reason is geography rather than driving: Chelmsford sits on Route 3 and near the I-495 corridor, Andover on I-93 and I-495, Weston at the junction of the Massachusetts Turnpike and Route 128, while Lynn, Malden and Cambridge are dense inner-core street grids with no limited-access highway inside their borders. Per-town crash totals and the highest-crash roads by name for all 349 Massachusetts communities are on the crash report, including Chelmsford, Andover, Weston, Lynn and Cambridge.

Pedestrian Crashes by Community, Almost All on Slow Streets

The same per-community cut, applied to pedestrian crashes, is close to unanimous.

Community	Pedestrian crashes	On roads posted 5 to 30	Share
Lawrence	145	144	99.3%
Fall River	213	206	96.7%
Lynn	268	258	96.3%
Cambridge	220	209	95.0%
Quincy	155	146	94.2%
Brockton	183	169	92.3%
New Bedford	197	179	90.9%
Springfield	214	168	78.5%
Boston	491	307	62.5%
Worcester	327	143	43.7%

Boston at 62.5 per cent and Worcester at 43.7 per cent are the two that stand apart, and the explanation in both cases is that a large share of each city’s road mileage is posted above 30 or carries no recorded limit at all: Boston’s arterials, the Storrow and Morrissey corridors, and in Worcester the I-290 and Route 9 frontage. Everywhere else in the list, a pedestrian struck in that city was struck on a street posted 30 or below at least nine times in ten.

If you were hurt walking in one of these cities, the local pages carry the town figures alongside the practice area: Lynn, Cambridge, Fall River, Lawrence, Brockton, New Bedford, Quincy, Springfield, Worcester and Boston.

How to Use These Numbers After a Massachusetts Crash, In Order

1. Find the posted limit at the exact location, not the road’s general character. Massachusetts limits change block to block, and the difference between a 30 and a 40 on the same named road is the difference between two bands in the table above.
2. Photograph the sign. A posted limit is a physical object that gets replaced, moved or knocked down. The crash record’s speed field is populated by the reporting officer, and 7.94 per cent of Massachusetts crash records have no posted limit in them at all.
3. Separate the posted limit from the speed actually travelled. They are different facts and only one of them is in this data. What the sign said is not evidence of how fast anyone was going.
4. Note the junction. A 35 or 40 mile per hour road with a traffic signal, a left turn or a curb cut is the arterial pattern that carries the highest injury share in the table, and the junction detail is in the Massachusetts intersection crash data.
5. Check the time of day and the road surface separately. Darkness and surface each move the numbers on their own, and they move them in different ways than speed does.
6. Get the crash report before the details fade. How to obtain one is set out in reporting a car accident in Massachusetts.
7. Do not let a posted limit become an argument about your fault. Massachusetts reduces recovery by a claimant’s share of fault and bars it above 50 per cent, which is covered in comparative negligence in Massachusetts.

Key Terms

• Posted speed limit. The signed limit at the crash location as recorded by the reporting officer in the SPEED_LIMIT field, not the speed any vehicle was travelling.
• Fatal rate per 1,000 crashes. Fatal crashes in a band divided by all crashes in that band, times 1,000. Used so bands of very different sizes can be compared with each other.
• Injury share. The percentage of a band’s crashes recorded as non-fatal injury crashes. It counts whether anyone was hurt, not how badly.
• Banded crashes. The 372,119 crashes carrying a posted limit between 5 and 65, which is the denominator for every percentage in this article.
• Off-scale value. One of the 952 records carrying a speed field that cannot be a Massachusetts posted limit, such as a negative number or a value above 65. Excluded and counted.
• Limited access highway. A road entered and left only at interchanges, which is most of what the 50 to 65 band contains and the reason that band has almost no pedestrian or bicycle crashes.

What This Does Not Show

Three limits are worth stating plainly, because a data article that only reports its findings is easy to over-read.

This is not a measure of how dangerous a road is per mile driven. A band with more crashes may simply carry more traffic. The 30 mile per hour band holds the most crashes in Massachusetts because most Massachusetts driving happens on streets posted 25 or 30, not because those streets are the worst.

This is not a measure of speeding. The field records what the sign said, not what anyone did. A crash on a road posted 25 tells you nothing about whether a driver was doing 25.

And this is not a causal finding. The bands differ in road design, traffic volume, junction density, lighting, who is walking nearby and what vehicles are present, all at once. Posted speed is correlated with every one of those.

Frequently Asked Questions

Q: Which Massachusetts speed limits carry the deadliest crashes?

A: Measured as fatal crashes per 1,000 crashes, the 60 mile per hour band is highest at 8.10, followed by 50 at 5.86, 65 at 5.64 and 45 at 5.40. The 60 figure rests on 15 fatal crashes out of 1,851 and should be read more cautiously than the others. Grouped, roads posted 50 to 65 run 4.93 fatal per 1,000 against 1.89 on roads posted 5 to 30, which is the clearest version of the finding.

Q: Do more Massachusetts crashes happen on fast roads or slow roads?

A: Slow roads, by a wide margin. Roads posted 5 to 30 miles per hour account for 217,500 of the 372,119 crashes with a recorded limit, 58.45 per cent, with the 25 and 30 bands alone holding 188,776 of them. Roads posted 50 to 65 account for 56,851.

Q: Why does the injury rate fall on the fastest Massachusetts roads?

A: The injury share peaks at 26.93 per cent on roads posted 45 and falls to 24.34 per cent across the 50 to 65 group, while the fatal rate keeps climbing. This article offers an inference rather than a finding, because the crash records do not carry the reason: the fastest roads are mostly limited access, where traffic runs one way and the common crash is a same-direction impact, while the 35 to 45 band is arterial road full of turning and crossing movements at speed.

Q: Where do pedestrian crashes happen in Massachusetts?

A: Overwhelmingly on slow streets. 4,541 of the 5,980 pedestrian crashes in the three years were on roads posted 5 to 30 miles per hour, against 83 on roads posted 50 to 65. In Lawrence the figure is 144 of 145, in Fall River 206 of 213 and in Lynn 258 of 268.

Q: Which Massachusetts community has the most crashes on high-speed roads?

A: Among communities with at least 2,000 crashes, Chelmsford has the largest share, with 920 of its 2,108 crashes on roads posted 50 to 65, or 43.64 per cent. Andover follows at 39.37 per cent and Auburn at 38.67 per cent. At the other end, Lynn recorded 4 such crashes out of 6,074, or 0.07 per cent.

Q: Does the posted speed limit affect a Massachusetts injury claim?

A: Not by itself. The posted limit is a fact about the location, and what matters in a claim is how the collision happened, what each driver did, and what the available insurance covers. A posted limit can become relevant evidence where speed is disputed, but Massachusetts fault is decided under the comparative negligence rule rather than by the sign at the roadside.

Q: Where does this data come from?

A: The MassDOT IMPACT crash records for calendar years 2022, 2023 and 2024, the same source behind the per-town figures on this site’s crash report. The pull returns 405,240 crashes, 1,087 of them fatal, and those totals match the data already published across this site on all five statewide measures.

Q: How many Massachusetts crash records have no posted speed limit?

A: 32,169 of 405,240, or 7.94 per cent, carry no posted limit at all, and a further 952 carry a value that cannot be a Massachusetts posted limit. Both groups are excluded from every figure in this article, and the remaining 372,119 crashes are the denominator throughout.

Q: Is Jimmy Knows AI giving me legal advice?

A: No. This is general information about Massachusetts crash data and Massachusetts law, not legal advice, and reading it does not create an attorney-client relationship. Statistics describe a population and say nothing about any particular crash. For advice about a specific situation, speak with a Massachusetts attorney.

Talking to a Lawyer

The useful thing in this data is not the ranking. It is that severity splits into two measures that do not move together, and the road a crash happened on determines which one is at stake. A collision on a Massachusetts arterial posted 35 or 40 is the most likely of any to injure somebody. A collision on a road posted 50 or above is the most likely to kill somebody and the least likely to involve anyone outside a vehicle. A collision on a street posted 25 or 30 is the ordinary Massachusetts crash, and is where almost every pedestrian and bicycle case in the Commonwealth begins.

Jim Glaser Law can be reached at (617) JIM-WINS. The line is answered 24 hours a day. The first telephone consultation is offered without charge. Cases accepted on a contingency basis carry no attorney fee unless there is a recovery, and case costs and expenses are addressed in the written fee agreement signed at intake.