PORTLAND – The Maine Turnpike Authority plans to introduce pacer vehicles later this month as its latest weapon to help slow traffic through construction zones.

The specially marked trucks will drive side-by-side through construction areas at 50 mph, forcing would-be speeders to follow at a safe speed.

“It’s new to Maine,” said Peter Merfeld, chief operating officer at Maine Turnpike Authority. He said pace vehicles have proved helpful in Seattle and Charleston, S.C.

The pace vehicles, combined with a doubling of police patrols, new electronic signs and other measures, are designed to protect motorists and construction workers who operate equipment within several feet of the travel lanes.

“It’s somewhat experimental,” said Paul Violette, executive director of the authority. “We’re going to see how it works.”

Violette said he doesn’t expect the measure to be popular with speeders, but it’s already a source of relief for contractors. Workers on the five-year turnpike widening project complain about having to stand within four feet of vehicles that whip by at speeds exceeding 70 mph.

Contractors will be widening a 3.7-mile stretch between Wells and Kennebunk used by nearly 45,000 vehicles per day. The third year of the project also includes the addition of third lanes to a 2.4-mile section between Biddeford and Saco used by 56,700 vehicles per day.

The pace vehicles should appear in the next few weeks. The contract for their operation requires that they be pickup trucks or larger, and have a flashing light and a 3-foot-by-5-foot “PACE VEHICLE” sign mounted on the backs.