Most of the 109-mile highway will have a 70 mph limit.
Speed limits on the Maine Turnpike will rise by 5 mph on Monday.
The maximum legal speed on most of the 109-mile turnpike will go from 65 mph to 70 mph, said Peter Mills, the Maine Turnpike Authority’s executive director.
The speed limit will stay at 65 mph south of mile 2.1 in Kittery.
The limit will increase to 60 mph from the current 55 mph in Greater Portland – from mile 44 in Scarborough to mile 52 in Falmouth – then increase to 70 mph from mile 52 to the northern end of the turnpike in Augusta.
On the Falmouth spur, which connects Interstate 295 to the turnpike, the speed limit will rise from 50 mph to 60 mph.
The speed limit on much of I-295 was increased to 70 mph this spring.
Mills said signs with the higher speed limits will be posted Monday, beginning around 5 a.m. About 100 signs must be replaced.
He said studies indicate that the speed limit can be increased to 70 mph safely. He said a study done by the Maine Department of Transportation after the speed limit was raised on I-295 indicated that most drivers had been going about 70 mph before the increase, and the average speed increased by only about 1 mph after the limit was raised.