The diet starts this fall.

A ?road diet? for a stretch of Petaluma Boulevard North, that is. After two years of planning and design, the City Council on Monday approved a bid for the $2.2 million project, which will reduce the number of travel lanes on the Boulevard from Lakeville to Washington streets from four to two.

Construction will begin by September, the city?s public works department said.

Along with the reduction in the number of lanes, a center left-turn lane and wider parking along the curbs will be created.

The project will improve safety by giving parked cars more space from passing vehicles, while allowing drivers turning left onto a driveway or side street to do so from the center lane rather than the inside travel lane, which backs up traffic, the city said.

The new northbound and southbound travel lanes will be 11 feet wide, rather than the current 91⁄2-foot width. Curb parking areas will be 8 feet wide rather than 6 feet.

City engineers have said the lane reduction should cut down significantly on the number of sideswipe accidents because traveling vehicles, parked cars and those turning left along that stretch will all enjoy wider lanes. There were 271 sideswipes and broadside collisions in that area between 1998 and 2003.

At the intersection of Petaluma Boulevard North and Washington Street, drivers traveling north and south on the Boulevard will have three new lane choices ? go straight, turn left or turn right.

Council members approved the construction contract for North Bay Construction with the exception of Mike O?Brien, who said questions remain about the effectiveness of the proposal and has voted against it in the past.

But other members said Petalumans they?ve spoken with have been waiting for the project, which will repair a bumpy stretch of road.

?It is a major problem from a maintenance standpoint, and I have heard from community members asking when this project will begin,? Mayor Pamela Torliatt said. ?I think it should be done sooner rather than later.?

At least three businesses on that stretch of Petaluma Boulevard North sent letters of support for the road diet to the council, though no members of the public spoke at Monday?s meeting.

The project is being funded with a $485,000 grant from the Bay Area?s Metropolitan Transportation Commission and $1.7 million in city and redevelopment money.

As part of the grant funding, the city agreed to add pedestrian and bicycle amenities to the repaving project and improve disability access, which delayed the start of the work.

(Contact Corey Young at corey.young@arguscourier.com)