Speed limits along much of the Maine Turnpike and the state’s interstate highways are expected to rise to 70 mph soon – a speed that’s closer to what motorists actually drive but which safety advocates say could lead to more fatalities.

The Maine Turnpike Authority said it plans to increase speed limits to 70 mph from Kittery to Scarborough and from Westbrook to West Gardiner, but the change won’t take effect until midsummer. The current speed limit is 65 mph.

The Maine Department of Transportation has proposed raising the Interstate 295 speed limit north of Tukey’s Bridge in Portland to 70 mph, although its final plans will not be announced until a news conference Tuesday.

Ted Talbot, a spokesman for MDOT, refused Friday night to discuss the details of Tuesday’s announcement, saying premature disclosure could lead people to drive faster on the busy Memorial Day weekend.

“Both agencies are raising speed limits by about 5 mph almost everywhere,” Peter Mills, executive director of the Maine Turnpike Authority, said Friday. He said he thinks the highways controlled by the Transportation Department “are going to go up first. … We had originally planned to go up at the same time, but we have to go through a rule-making process,” he said of the turnpike authority, which operates under a different state law.

The Maine Department of Transportation’s authority to unilaterally change interstate speed limits was made possible by legislation last year that shifted responsibility away from the Legislature.

Rep. Justin Chenette, D-Saco, who sponsored the legislation, said it was designed to put the issue in the hands of traffic engineers, not politicians.

“If everybody is already going 75, then that’s the safest speed,” he said Friday. “North of Portland, as you get close to West Gardiner, it makes sense to reflect what people go already. Anybody who drives that morning commute will know if you’re going 65 in certain sections, you’re actually potentially causing an accident.”

When advocating for his legislation, Chenette cited a 1992 federal study that said at 58 experimental sites where speed limits were raised, the number of crashes dropped. He said that is because people going more slowly than the general flow of traffic can pose a hazard, even if that slower speed is the speed limit.

Most crashes in Maine listed as due to excessive speed occur during foul weather when the motorist was driving too fast for the conditions but probably well below the posted speed limit, according to the Maine Turnpike Authority.

Chenette’s legislation requires the MDOT commissioner to get the approval of the Maine State Police but that seems assured.

“The colonel has been consulted,” state police spokesman Steve McCausland said, referring to Col. Robert Williams, chief of the state police. “All indications are that the proposed limits will be increased.”

Not all traffic authorities agree, however, on the impact of raising speed limits.

“The trend is speed limits are increasing and it’s really the reason we’re not making more progress on fatal crashes,” said Jonathan Adkins, executive director of the Governors Highway Safety Association, an advocacy group. There are about 10,000 speed-related fatalities each year in the U.S., he said. “The laws of physics haven’t changed. When you’re going 80 to 90 mph and you crash, the likelihood of surviving is going to go down quite a bit.”

Whatever the posted speed limit is, people will exceed it, he said.

“It’s really a cultural issue. The public accepts speeding. They think it’s their right,” he said. “They don’t see this as a traffic safety issue. They see it as a revenue generator for the state. There’s not a MADD (Mothers Against Drunk Driving) for speeding.”

The changes may not get much objection from motorists.

“I actually think that’s awesome because most of us do 70 anyway,” said Tonya Kinney of Knox.

She doubts the increase in the speed limit will lead to an increase in accidents. “Everybody’s already traveling at that rate of speed,” she said. “Why would it increase accidents?”

Rich Ullrich of Brookline, New Hampshire, said he won’t mind the change. His state recently increased speed limits north of Concord without any problems, he said.

“Everybody is driving 70 anyway,” he noted.

Advocates of raising the speed limit say drivers are already going well above the speed limit in most areas and adjusting the legal limit upward won’t necessarily mean everyone speeds up.

“People are going this fast and they apparently are doing it safely because our safety statistics are very strong,” Mills said. “If they’re violating the law at 70 mph, but everybody’s doing it, why do you have a law?”

The changes could lead to more strict enforcement of the new limits by state police, he said.

Mills provided data showing that on long stretches of the Maine Turnpike where the posted speed limit is 65 mph, the average travel lane speed ranges from 67 mph in South Portland to 77 mph a few miles south of West Gardiner. In the passing lanes, average speeds were 72 mph and 80 mph in the same locations.

Data from the turnpike authority show that 85 percent of motorists currently travel at or below the planned new limits. The data also show that the crash rate and fatality rate for the turnpike and interstates was much lower between 2009 and 2013 than it was for all other roads.

Rep. Charles Kenneth Theriault, D-Madawaska, House chairman of the Legislature’s Transportation Committee, said that when considering the legislation allowing state transportation officials to determine speed limits, committee members looked at the experience on Interstate 95 between Old Town and Houlton, where the speed limit had been raised to 75 mph in 2011. There was no increase in fatal or serious crashes on that stretch, he said.

He said he is personally not opposed to raising the speed limit. “People usually travel a little bit over the speed limit, probably use that 3-, 4-, 5-mile-an-hour variance.” Changing the limit would correspond with their behavior, he said.

The design of roadways and of cars continue to evolve, Mills said. He said traffic engineers tested the contours of the roads to make sure raising the speed limit would not create dangerous conditions. The turnpike has vastly expanded the areas protected by guardrails.

The MDOT and turnpike authority have discussed raising the speed limit before.

“Both agencies have been thinking about it and chatting about it for years,” Mills said. “We did not want to do it on our own. We have a policy that says we will simply be consistent.”

Mills said there has been some opposition to raising the speed limit that is not related to safety.

During past discussions on the issue, some in the trucking industry said it costs a company more in fuel than it does in labor to have a driver go 70 mph versus 65 mph, he said.

When the speed limit was raised on I-95 between Old Town and Houlton from 65 to 75 mph, Maine became the first state east of the Mississippi to have such a high speed limit since the 1970s.

In reaction to the oil crisis of 1973, President Nixon signed into law a national speed limit of 55 mph as a way to conserve energy at a time when the Arab oil embargo drove up prices and cut supply.

The federal government backed off that requirement and in 1987 the interstate speed limit in most of Maine was increased to 65 mph.

An MDOT draft proposal from last December, titled “Proposed speed limit changes for discussion only,” was among the explanatory documents released Friday by the turnpike authority. The draft called for increasing the speed limit on the divided highway section of Route 1 between Brunswick and Bath to 65 mph from 55 mph. A similar increase was proposed for I-95 between Mile 114 and Waterville, Mile 134 to Mile 181, and Mile 188 to Old Town. The stretch from Mile 181 to just north of Hogan Road in Bangor was proposed to go from 55 to 60 mph.

David Hench can be contacted at 791-6327 or at:

[email protected]

Twitter: @Mainehenchman