The Official Website of The Massachusetts Department of Transportation - Highway Division

Roadway Functional Classification

Home > Departments > Traffic and Safety Engineering > Crash Data > Crash Rates > Roadway Functional Classification

Traffic Engineering

Crash Rates by Roadway Functional Classification

The statewide average crash rates by roadway functional classification are based upon the total number of located crashes and the vehicle miles traveled for each roadway functional classification. All crashes, that are contained in the statewide crash system and able to be located to a geographic point, were linked to the roadway network and to a particular roadway functional classification (for crashes along a roadway that occurred at an intersection, the higher functional classification was assumed). The sum of all crashes for each functional classification was then calculated. The exposure, in this case, the million vehicle miles traveled (MVMT) by functional system, was obtained from MassDOT Planning as part of their HPMS reporting. For each functional classification, the total number of crashes was then divided by the MVMT.

In 2015, approximately 95% of all crashes were able to be geographically located to a point. However, it should be noted that the rate for which crashes are able to be located is not uniform for each roadway, thereby impacting the crash rate on a particular roadway and subsequently on the average crash rate by functional classification.

2015 Average Crash Rates, per Million Vehicle Miles Traveled, by Federal Functional Classification


(Based upon crash information queried on November 14, 2017)
Roadway Federal Functional Classification Rural Urban
Statewide 0.95 2.21
Interstate 0.40 0.61
Principal arterial - other freeways and expressways 0.75 0.83
Principal arterial - other 0.64 3.29
Minor arterial 0.90 3.63
Major collector 1.38 3.62*
Minor collector 2.30 -
Local 1.20 2.21

Notes on Functional Classification Data:

  • * This rate is for all Urban Collector roads, including both Urban Major Collector and Urban Minor Collector roadways.
  • If a crash occurred at an intersection or along two different functional classifications, the crash was assigned to the higher order roadway.
Translation Disabled  | Translation Support