Information on Speed Limit Regulations

Posted speed limits are established through the issuance of special speed regulations. On state highways, the Massachusetts Highway Department (MassHighway) is responsible for conducting an engineering study to establish a speed regulation, which is then jointly signed by both MassHighway and the Registry of Motor Vehicles according to Chapter 90, Section 18 of the Massachusetts General Laws (MGL). On municipal roadways, the municipality, usually in conjunction with MassHighway, collects data relative to establishing a speed limit. The Traffic Engineering section reviews this data and a speed regulation is then drafted by MassHighway and returned to the municipality for approval. After the city or town approves the speed regulation, it is then returned to MassHighway and jointly signed by the Registry of Motor Vehicles and MassHighway. (MGL Ch. 90, S.18)

However, Chapter 90, Section 17 of the MGL dictates statutory speed limits in the absence of official speed postings under 90-18. In other words, if a speed limit has not been established under 90-18 (which requires the posting of speed limits according to a Special Speed Regulation which is the result of an engineering study) the roadway can be enforced according to 90-17 (no speed signs posted), which is 20mph in a school zone, 30 mph in a thickly settled or business district for a distance of 1/8 of a mile, 40mph on an undivided highway outside of a thickly settled or business district for a distance of 1/4 of a mile, and 50 mph on a divided highway outside of a thickly settled or business district for a distance of 1/4 of a mile.

To obtain speed regulation information and engineering support data, where available, an official request must be made to the Chief Counsel's office at MassHighway through the Freedom of Information Act. Please include your contact information and email address along with a brief description of the information you are inquiring about.

MassHighway Policy on Speed Zoning

It has been the consistent objective of MassHighway over the years to provide means to promote safe and efficient traffic flow in the Commonwealth. The goal of our Speed Limit Traffic Control Program has always been to provide appropriate and enforceable speed limits on all paved streets ad highways within the Commonwealth in the best interest of the motoring public's right to use a roadway in a reasonable and proper manner. The ideal speed limit is both acceptable to the prudent driver and enforceable by our police departments.

Engineering Studies and Speed Zoning

A prerequisite to establishing speed regulations and posting speed limits is a comprehensive engineering study at each location where speed control is contemplated. The purpose of the study is to establish a speed limit that is safe, reasonable and self-enforcing.

< Back