Two Center City bike lanes have been so successful that they should become permanent and new ones should be considered, according to a top city official.

Mayor Nutter is likely to approve a recommendation to continue the revised traffic configurations on Pine and Spruce Streets, said Rina Cutler, deputy mayor for transportation and utilities.

"He's obviously been a fan of the notion that everybody needs to share the roadways," said Cutler, who announced her intentions to a packed meeting at a University of the Arts auditorium Thursday night.

Most of the 250 or so attendees were pleased, said Sarah Clark Stuart, campaign director for the Bicycle Coalition of Greater Philadelphia.

Dedicated lanes make riding safer and easier while making sidewalks safer for pedestrians, she said.

In late September, eastbound Pine Street and westbound Spruce lost a lane for cars and gained a six-foot-wide lane for bikes from 22d Street deep into Society Hill - creating the first east-west bike routes in Center City.

"It's night and day compared to a lane that you share with cars, because there's more distance between you and moving vehicles," Stuart said. "You know you're not going to get passed by inches."

As a result, two-wheeled traffic nearly doubled on those streets - up to 103 bikes an hour at one Spruce Street intersection - while declining by more than 40 percent on adjacent sidewalks, according to a coalition count, Stuart said.

The city's data also showed that car traffic was not significantly hampered, Cutler said.

Adding more Center City routes - including at least one going north-south - is likely, the deputy mayor said.

"Our goal is to figure out locations where it is possible for that to happen," she said. "I expect that these will not be the last ones."

The city has about 200 miles of bike lanes, plus 50 miles of bike trails.

Encouraging bicycling can benefit the city in many ways, from restraining car traffic and pollution to improving health and fitness, Cutler said.

That's why her department has been supporting bike-friendly measures. New racks keep being installed, and the city now has 4,000 "bicycle parking spaces," she said.

On blocks where the Parking Authority was installing payment kiosks, the city asked that some meter poles be left, so they could be capped and used for locking bicycles.

The city is also exploring bike-sharing programs, which would let would-be riders borrow a bike in one area and drop it off for others to find somewhere else.

As for recent City Council proposals to start a bike-registration program and increase fines, Cutler said the administration would work with Council to make sure the first priority is safety.

The coalition favors education and enforcement. "The legislation is unproductive as it's written," Stuart said.