Speed limits — Massachusetts Permit Test

You must never travel so fast that it is not safe, which is the fundamental speed law, even where the posted limit is higher.

The posted number is a ceiling, not a permission. In rain or snow the safe speed is below it and the law is the safe speed.

You must never travel so fast that it is not safe. That is the fundamental speed law.

Smaller highways have speed limits of 55 mph or lower.

Interstates run to 65 and a smaller highway looks much the same at speed. Fifty-five is the ceiling once you leave the limited-access routes.

Smaller highways have speed limits of 55 mph or lower.

Unless posted otherwise, your speed is not reasonable and proper above 30 mph in a thickly settled or business district.

Thirty is the default where the buildings are close together, and some towns post twenty-five instead.

Unless posted otherwise, your speed would not be reasonable and proper if you drive over... • 20 mph in a school zone • 30 mph in a thickly settled or business district (unless there are signs showing a 25 mph limit)

Unless posted otherwise, your speed is not reasonable and proper above 40 mph outside a thickly settled or business district.

Once the buildings thin out the default rises by ten. It is still a default and not a posted limit.

Unless posted otherwise, your speed would not be reasonable and proper if you drive over... • 20 mph in a school zone • 30 mph in a thickly settled or business district (unless there are signs showing a 25 mph limit) • 40 mph outside a thickly settled or business district

Unless posted otherwise, your speed is not reasonable and proper above 50 mph on a highway outside a thickly settled or business district.

Fifty is the highest of the four defaults, and it applies only on a highway away from the buildings.

Unless posted otherwise, your speed would not be reasonable and proper if you drive over... • 20 mph in a school zone • 30 mph in a thickly settled or business district (unless there are signs showing a 25 mph limit) • 40 mph outside a thickly settled or business district • 50 mph on a highway outside a thickly settled or business district

A thickly settled district is an area where buildings are fewer than 200 feet apart for a distance of a quarter mile or more.

It is a measurement rather than a feeling about a place. Two hundred feet and a quarter mile are the two figures that decide it.

A “thickly settled district” is an area where buildings are fewer than 200 feet apart for a distance of 1/4 mile or more.

Limited-access highways like interstate routes have speed limits from 50 to 65 mph, and smaller highways 55 mph or lower.

Sixty-five is the top of the range in this state, and only on the biggest roads. Nothing here is posted higher.

Limited-access highways, like interstate routes, have speed limits from 50 to 65 mph.

There is a minimum speed of 40 mph on the Massachusetts Turnpike.

A minimum matters as much as a maximum on a road where everybody else is doing seventy. Driving far below it is its own hazard.

There is a minimum speed of 40 mph on the Massachusetts Turnpike.

There is a minimum speed of 20 mph in the Boston Harbor tunnels.

The tunnels are narrow and have nowhere to pull over. Traffic crawling through them backs up fast.

There is a minimum speed of 20 mph in the Boston Harbor tunnels (Callahan, Sumner, and Ted Williams).

Even where no minimum speed is posted, a police officer may order a driver to the side of a state highway for slowing traffic.

Driving very slowly on a fast road makes everybody else change lanes around you, which is where the crashes come from.

Even without a minimum speed, a police officer may order a driver to the side of a state highway if they are slowing traffic.

Driving 40 mph in a heavy rainstorm where the limit is 50 mph can still get you a ticket for driving too fast.

Being under the posted number is no defense if the conditions are bad. The fundamental speed law reaches above and below the sign.

If you drive 40 mph in a heavy rainstorm on a highway with a speed limit of 50 mph, you can get a ticket for driving too fast.

What is the fundamental speed law?

Never travel so fast that it is not safe. The posted number is a ceiling, not a permission. In rain or snow the safe speed is below it and the law is the safe speed. Massachusetts Driver's Manual, p.79: “You must never travel so fast that it is not safe. That is the fundamental speed law.”