The idea of closing one of the driving lanes on Charleston's lower Ashley River bridges to make it exclusively for bicycles and pedestrians has hit a snag.

Several members of City Council are expressing reservations about the idea as worries mount over what reducing the bridge's surface from four lanes to three would mean. Thousands of vehicles cross the bridges daily - more than 50,000 by some estimates.

"I'm concerned we are creating a traffic problem for the citizens west of the Ashley," Councilman Bill Moody said.

Another fear is that even if one of the northbound lanes of the T. Allen Legare Jr. Bridge is closed to cars and trucks, the cycling and walking experiment still might not last more than a few years.

That's because the S.C. Department of Transportation estimates that by 2020, bridge traffic into the city along U.S. Highway 17 will become too cluttered to operate with only three lanes, officials said.

"I'm not sure I want to give up that lane for a limited basis," Moody added. "Probably sooner than later we're going to have to give it back."

Others questioned whether there is truly a widespread demand for adding a bike and pedestrian lane, since there has been no official survey.

The push-back comes as City Council last week delayed approving an agreement with Charleston County to move forward on the bike-path idea that has been in the works for several years. The county will pay for the bike lane inclusion from half-cent sales tax money. Recent estimates put the cost at about $2 million. One design plan has suggested creating a guardrail barrier delineating the path from vehicular traffic.

Advocates say the route is needed as an alternative to provide a recreational and commuting path into downtown Charleston. Others say the lane could help keep cars out of the city and its parking spaces.

Mayor Joe Riley backs the idea, saying it would open up an opportunity for bikers and walkers bound for high-demand areas on the peninsula, including the Medical University of South Carolina and the College of Charleston.

Councilman Aubry Alexander also questioned whether it was better to wait and see the results of the city's traffic study on biking on the James Island connector before moving forward. That way, he said, a region-wide cycling plan could be considered.

Alexander added that if the bike lane has a less than six-year lifespan, it also doesn't pass the 25- or 50-year test that is used as a benchmark in evaluating city projects.

"Is it a want or is it a need?" he said of the bike path idea. "Do we really have to have this thing?"

City Council will take up the bridge-lane debate again Feb. 25 when the issue is expected to be part of the city's Traffic and Transportation Committee meeting.

Reach Schuyler Kropf at 937-5551.