Bulging with extra capacity that allows drivers to speed through a residential area, a mile-long stretch of South McDowell Boulevard will be narrowed to one lane in each direction as part of a ?road diet? neighbors have been seeking.

From Weaverly Drive at the north end to Casa Grande Road on the south, the four-lane arterial roadway will be re-striped to create single southbound and northbound lanes with a dual left-turn lane in the median, along with six-foot bike lanes in each direction and eight-foot shoulders for on-street parking.

The change will be made as part of a repaving project on South McDowell and will help reduce speeding and collisions in the area, city traffic engineer Frank Penry told the City Council Monday.

The ?calming effect? of directing traffic along a single through lane in each direction should also discourage large trucks from using South McDowell, rather than the freeway, to reach shopping centers further north, he said.

The ?road diet? segment is surrounded by single-family homes that open onto the busy street and neighbors have been asking for safety improvements there, Penry said.

Combined with a roundabout at the intersection of Baywood Drive and South McDowell ? the halfway point of the new configuration ? the reduced number of lanes will encourage slower traffic, neighbors said.

?It?s going to slow everything down, which is what we need because it?s a neighborhood,? said Toni Mattos, whose home is at the corner of Baywood and South McDowell.

Currently, there are two 10-foot travel lanes in each direction in that segment of South McDowell, with 12-foot shoulders that must be shared between bicyclists and parked cars.

Under the new plan, the width of the single travel lanes would not be reduced, but remain at 10 feet. The 15-foot center left-turn lane would be created where a median curb is not already in place.

Drivers turning left from side streets along the reconfigured road would only have to keep their eyes on two lanes of traffic, instead of four, and could pull into the center lane to wait to merge with traffic, Penry said.

Northbound drivers would begin to merge into one lane south of the Casa Grande intersection. Southbound drivers would merge from two lanes to one ahead of the Weaverly intersection.

The council unanimously approved the plan. The $887,000 paving and roundabout project, paid for with a combination of traffic impact fees, gas tax money and county and federal grants, is expected to be completed later this spring.

There is no additional cost for the road diet because the newly paved road would have to be re-striped anyway, Penry said.

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