Seattle Mayor Mike McGinn's "road diet" for West Nickerson Street is drawing opposition from Councilman Tom Rasmussen, who says the project should probably be delayed until 2016 -- when other corridors including two-way Mercer Street and the Alaskan Way Tunnel are completed, and their traffic detours let up.

Rasmussen wants to scrutinize the plan June 8 in the council's transportation committee, which he chairs.

In a typical "road diet," a four-lane arterial is restriped so there are two traffic lanes and a center left-turn lane -- and often bike lanes, plus some raised medians to help pedestrians. There have been 24 such lane reductions in the city since 1972.

The mayor, a longtime environmental activist, announced the Nickerson road diet May 11, as part of a re-emphasis on walking, biking and transit projects. One goal is for lower car speeds to improve pedestrian safety; the street passes through Seattle Pacific University.

Peter Hahn, the new transportation director, said he had authority to carry out the $200,000 makeover without further council or mayor actions -- and if it failed, the road diet could be easily reversed.

Rasmussen says he heard an immediate outcry from neighborhood and Democrat groups. Nickerson is one of only two east-west streets directly feeding Ballard industries. Meanwhile, angry drivers tell the Times that bicyclists should use the Ship Canal Trail, a block away.

Rasmussen questioned the Nickerson plan at a small noontime forum with the Metropolitan Democratic Club of Seattle. Afterward, he said the council might a) pass a budget proviso withholding road-diet money, b) pass a recommendation for or against the plan, or c) watch what happens, perhaps adding language repealing the road diet if things went bad.

Meanwhile, the city says that its 2007-08 road diet on Stone Way North is reducing total collisions, though rear-end crashes increased at a confusing road segment near North 40th Street. Rasmussen said a road diet on Fauntleroy Way Southwest has been well-received.

McGinn isn't wavering. Asked if it would take a veto-proof six council votes to stop McGinn, mayoral spokesman Aaron Pickus said that's "a fair interpretation."