The official description reads as follows:What does "Thickly Settled" mean?
"Statutory speed limits exist in the absence of special speed regulations. MGL c. 90 § 17 dictates that if no official speed postings have been made per MGL c. 90 § 18, then drivers are expected to travel at speeds that are reasonable and proper. On roads within thickly settled or business districts, the reasonable and proper rate of speed is 30 mph. In addition, cities and towns that opt-in to MGL c. 90 § 17C may further reduce the reasonable and proper speed within thickly settled or business districts to 25 mph."
I think it's interpreted in most towns that if there are no signs you need to go 30 (or 25). I'd be curious how it's argued in courts by people trying to get out of speeding tickets.
I did have a failure of recognition yesterday when the car interpreted a route 60 sign as a 60 mph hour zone on a road with 35 mph speed limit. The route sign is just a black on white 60 with no text at all, so not surprised that it interpreted it as a speed limit sign.
Not good though.