Fatal Crash Data

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.

Deaths on I-495 in Massachusetts by year

1020201620182020202220242016: 262024: 16
YearFatal crashesDeaths
20241316
20231112
20222022
20211314
20201011
20191111
20181213
20171616
20162026
20151414

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 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 in I-495 in Massachusetts from 2015 to 2024; the 6 listed held 100%. Counties are listed from 5 fatal crashes.

County20242015 to 2024Deaths
1Middlesex County54041
2Essex County22832
3Bristol County02124
4Plymouth County22025
5Norfolk County21616
6Worcester County21517

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

Too few crashes to name a heaviest slot. The grid shows the shares; a share is only given over 20 crashes.

Share of fatal crashes in I-495 in Massachusetts by weekday and time of day, 2015 to 2024, in percent
Midnight to 44 to 8 am8 to noonNoon to 44 to 8 pm8 to midnight
Sun3.6 percent, 5 fatal crashes1.4 percent, 2 fatal crashes2.1 percent, 3 fatal crashes2.1 percent, 3 fatal crashes2.1 percent, 3 fatal crashes2.1 percent, 3 fatal crashes
Mon0.7 percent, 1 fatal crashes0.0 percent, 0 fatal crashes2.1 percent, 3 fatal crashes2.1 percent, 3 fatal crashes0.0 percent, 0 fatal crashes3.6 percent, 5 fatal crashes
Tue2.9 percent, 4 fatal crashes3.6 percent, 5 fatal crashes0.7 percent, 1 fatal crashes2.9 percent, 4 fatal crashes2.1 percent, 3 fatal crashes0.0 percent, 0 fatal crashes
Wed2.9 percent, 4 fatal crashes1.4 percent, 2 fatal crashes3.6 percent, 5 fatal crashes0.0 percent, 0 fatal crashes3.6 percent, 5 fatal crashes1.4 percent, 2 fatal crashes
Thu1.4 percent, 2 fatal crashes5.0 percent, 7 fatal crashes1.4 percent, 2 fatal crashes1.4 percent, 2 fatal crashes3.6 percent, 5 fatal crashes4.3 percent, 6 fatal crashes
Fri3.6 percent, 5 fatal crashes2.9 percent, 4 fatal crashes2.1 percent, 3 fatal crashes2.1 percent, 3 fatal crashes3.6 percent, 5 fatal crashes2.1 percent, 3 fatal crashes
Sat3.6 percent, 5 fatal crashes4.3 percent, 6 fatal crashes0.7 percent, 1 fatal crashes2.9 percent, 4 fatal crashes2.1 percent, 3 fatal crashes5.7 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 eventFatal crashesShare
Fixed object (tree, pole, barrier, ditch)5942%
Collision with another vehicle5237%
Rollover117.9%
Other85.7%
Pedestrian64.3%
Parked vehicle32.1%
Cyclist10.7%
Not reported00.0%

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

A drinking driver was recorded in 32% of fatal crashes in I-495 in Massachusetts from 2015 to 2024, above the Massachusetts share of 30%; speeding in 32%, above the Massachusetts share of 29%; a hit-and-run in 2.1%, below the Massachusetts share of 4.9%; 53% of passenger-vehicle occupants killed with belt use known were unbelted, below the Massachusetts share of 62%. Shares of fatal crashes from 2015 to 2024, against the share across all of Massachusetts. A share is only given over 20 crashes.

I-495Massachusetts
On rural stretches2.9%6.6%below the Massachusetts share
At or near an intersection0.0%26%below the Massachusetts share
In the dark, road unlit42%19%above the Massachusetts share
A drinking driver32%30%above the Massachusetts share
Speeding32%29%above the Massachusetts share
Occupants killed unbelted53%62%below the Massachusetts share
Hit-and-run2.1%4.9%below the Massachusetts share
A motorcycle involved5.0%16%below the Massachusetts share
Pedestrians among the dead5.2%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 in 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.
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

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. A fatal crash is one in which someone died within 30 days. The full method.