I-495 in Massachusetts: fatal crashes
From 2015 to 2024, 140 fatal crashes on I-495 in Massachusetts killed 155 people, the most of any numbered road in Massachusetts. In 2024 there were 13 fatal crashes and 16 deaths on the road.
An interstate running through 6 counties of Massachusetts. All fatal crashes in Massachusetts. I-495 in every state.
Deaths on I-495 in Massachusetts by year
| Year | Fatal crashes | Deaths |
|---|---|---|
| 2024 | 13 | 16 |
| 2023 | 11 | 12 |
| 2022 | 20 | 22 |
| 2021 | 13 | 14 |
| 2020 | 10 | 11 |
| 2019 | 11 | 11 |
| 2018 | 12 | 13 |
| 2017 | 16 | 16 |
| 2016 | 20 | 26 |
| 2015 | 14 | 14 |
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
Where on I-495 in Massachusetts: the counties with the most fatal crashes
Middlesex County had the most fatal crashes on I-495 from 2015 to 2024: 40, with 41 deaths. Middlesex, Essex and Bristol counties together held 64% of fatal crashes on I-495 in Massachusetts from 2015 to 2024. Counties are listed from 5 fatal crashes.
| County | 2024 | 2015 to 2024 | Deaths | |
|---|---|---|---|---|
| 1 | Middlesex County | 5 | 40 | 41 |
| 2 | Essex County | 2 | 28 | 32 |
| 3 | Bristol County | 0 | 21 | 24 |
| 4 | Plymouth County | 2 | 20 | 25 |
| 5 | Norfolk County | 2 | 16 | 16 |
| 6 | Worcester County | 2 | 15 | 17 |
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
When fatal crashes happen on I-495 in Massachusetts
140 fatal crashes on I-495 in Massachusetts from 2015 to 2024 have a known time, too few for any one weekday and time of day to stand out. The worst hour is 6 am to 7 am; the worst month is July.
| Midnight to 4 | 4 to 8 am | 8 to noon | Noon to 4 | 4 to 8 pm | 8 to midnight | |
|---|---|---|---|---|---|---|
| Sun | 3.6 percent, 5 fatal crashes | 1.4 percent, 2 fatal crashes | 2.1 percent, 3 fatal crashes | 2.1 percent, 3 fatal crashes | 2.1 percent, 3 fatal crashes | 2.1 percent, 3 fatal crashes |
| Mon | 0.7 percent, 1 fatal crash | 0.0 percent, 0 fatal crashes | 2.1 percent, 3 fatal crashes | 2.1 percent, 3 fatal crashes | 0.0 percent, 0 fatal crashes | 3.6 percent, 5 fatal crashes |
| Tue | 2.9 percent, 4 fatal crashes | 3.6 percent, 5 fatal crashes | 0.7 percent, 1 fatal crash | 2.9 percent, 4 fatal crashes | 2.1 percent, 3 fatal crashes | 0.0 percent, 0 fatal crashes |
| Wed | 2.9 percent, 4 fatal crashes | 1.4 percent, 2 fatal crashes | 3.6 percent, 5 fatal crashes | 0.0 percent, 0 fatal crashes | 3.6 percent, 5 fatal crashes | 1.4 percent, 2 fatal crashes |
| Thu | 1.4 percent, 2 fatal crashes | 5.0 percent, 7 fatal crashes | 1.4 percent, 2 fatal crashes | 1.4 percent, 2 fatal crashes | 3.6 percent, 5 fatal crashes | 4.3 percent, 6 fatal crashes |
| Fri | 3.6 percent, 5 fatal crashes | 2.9 percent, 4 fatal crashes | 2.1 percent, 3 fatal crashes | 2.1 percent, 3 fatal crashes | 3.6 percent, 5 fatal crashes | 2.1 percent, 3 fatal crashes |
| Sat | 3.6 percent, 5 fatal crashes | 4.3 percent, 6 fatal crashes | 0.7 percent, 1 fatal crash | 2.9 percent, 4 fatal crashes | 2.1 percent, 3 fatal crashes | 5.7 percent, 8 fatal crashes |
By hour
By month
- Jan7.9%
- Feb8.6%
- Mar4.3%
- Apr4.3%
- May6.4%
- Jun7.1%
- Jul12.9%
- Aug7.1%
- Sep8.6%
- Oct11.4%
- Nov12.1%
- Dec9.3%
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
What fatal crashes on I-495 in Massachusetts first hit
The first harmful event was a fixed object such as a tree, pole or barrier in 42%; a collision with another vehicle in 37%, a rollover in 7.9%, a pedestrian in 4.3%.
| First harmful event | Fatal crashes | Share |
|---|---|---|
| Fixed object (tree, pole, barrier, ditch) | 59 | 42% |
| Collision with another vehicle | 52 | 37% |
| Rollover | 11 | 7.9% |
| Other | 8 | 5.7% |
| Pedestrian | 6 | 4.3% |
| Parked vehicle | 3 | 2.1% |
| Cyclist | 1 | 0.7% |
| Not reported | 0 | 0.0% |
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
How fatal crashes on I-495 in Massachusetts compare with the state
The largest difference from Massachusetts: from 2015 to 2024, 0.0% of fatal crashes on I-495 in Massachusetts were at or near an intersection, against 26% across Massachusetts. Also above the Massachusetts share: unlit roads at night. Below it: unbelted occupants, motorcycles and pedestrians. Shares of fatal crashes from 2015 to 2024, against the share across all of Massachusetts. A share is only given over 20 crashes; above or below means more than chance would give on 140 crashes.
| I-495 | Massachusetts | ||
|---|---|---|---|
| On rural stretches | 2.9% | 6.6% | about the same as the Massachusetts share |
| At or near an intersection | 0.0% | 26% | below the Massachusetts share |
| In the dark, road unlit | 42% | 19% | above the Massachusetts share |
| A drinking driver | 32% | 30% | about the same as the Massachusetts share |
| Speeding | 32% | 29% | about the same as the Massachusetts share |
| A distracted driver (as recorded) | 14% | 12% | about the same as the Massachusetts share |
| Occupants killed unbelted | 53% | 62% | below the Massachusetts share |
| Hit-and-run | 2.1% | 4.9% | about the same as the Massachusetts share |
| A motorcycle involved | 5.0% | 16% | below the Massachusetts share |
| Pedestrians among the dead | 5.2% | 20% | below the Massachusetts share |
Source: NHTSA Fatality Analysis Reporting System (FARS), 2024 Annual Report File (released April 2026, subject to revision). How we count
Questions about fatal crashes on I-495 in Massachusetts
- How many fatal crashes have there been on I-495 in Massachusetts?
- 140 fatal crashes killed 155 people on I-495 in Massachusetts from 2015 to 2024. In 2024 there were 13 fatal crashes and 16 deaths. Source: NHTSA's Fatality Analysis Reporting System (FARS).
- Where on I-495 in Massachusetts do the most fatal crashes happen?
- Middlesex County had the most fatal crashes on I-495 from 2015 to 2024: 40, with 41 deaths. Essex County was second with 28.
Other roads in Massachusetts with a page
- I-90
- I-93
- I-95
- State Highway 140
- State Highway 24
- State Highway 28
- State Highway 3
- State Highway 9
- US 1
- US 20
All fatal crashes in Massachusetts, with every road ranked.
Where the I-495 numbers come from
Counted from NHTSA's Fatality Analysis Reporting System, 2024 Annual Report File: every fatal crash whose road NHTSA filed as I-495 in Massachusetts (filed under 6 spellings, such as "I-495", "I-495 N", "I-495 NORTH", "I-495 S"). Ramps, frontage and service roads are left out. Where two routes share a road, NHTSA files each crash under one of them, so a shared stretch counts on one route only. A fatal crash is one in which someone died within 30 days. Totals in state and news reports for a road usually differ: they include ramps and frontage roads, or count from preliminary reports. The full method.