A yearlong road reconstruction project on William Clarke Drive in Westbrook is expected to cause significant traffic delays on Main Street.

The $5.3 million project will start Tuesday at the intersection of Saco Street and William Clark Drive and extend eight-tenths of a mile to the Westbrook Arterial.

R.J. Grondin & Sons was hired to widen the road and build a raised landscaped median. Left-turn lanes will be created at major intersections, and the traffic signals along the stretch will be replaced.

A traffic signal will be added at the intersection of Mechanic Street and William Clark Drive. The project also calls for a sidewalk to be built on the south side of William Clark Drive.

Eric Dudley, the city’s engineer, said the project is intended to make pedestrians safer, increase the road’s capacity for traffic and improve the aesthetics of the corridor.

“We have a fairly dense residential neighborhood on the south side and retail stores and restaurants on the north side,” Dudley said.

“There’s a stretch of road that is very dangerous between Spring and Mechanic streets. We’re trying to increase safety to the pedestrian facilities.”

Westbrook officials say one lane will be closed, leaving three lanes open to traffic. Some of the work will be done at night. The work is expected to be complete by July 2011.

Police Capt. Tom Roth said the project will cause traffic congestion on nearby Main Street, which may increase traffic along River Road and Route 302.

“We urge motorists to be patient during the process and understand there are only so many roads they can use to divert,” Roth said. “We’re going to do our best to mitigate the issues.”

Some businesses will be affected, including Baker’s Bench and Sportsman’s True Value.

“Whatever the town decides to do, we are stuck with,” said Kerry Kilcline, manager of Sportsman’s True Value on Central Street.

“Hopefully, it will run smooth enough that it won’t impact our business.”

The project will be paid for with money from the U.S. Department of Transportation. The city will contribute just over a $1 million, which was approved in the 2010-11 municipal budget.

Staff Writer Melanie Creamer can be contacted at 791-6361 or at:

mcreamer@pressherald.com