Pothole politics moved to center stage at City Hall on Tuesday when Mayor Ed Lee and six supervisors proposed a $248 million November bond measure to repave streets, shore up aging bridges, tunnels and public staircases, and create hundreds of new curb ramps for wheelchair users.

Money also would be used to landscape some of the city's bleaker roadways, as has been done in recent years along the Divisadero Street, Valencia Street and Leland Avenue commercial corridors, and to install new traffic signals that give Muni buses and streetcars priority at intersections.

The ambitious plan, even if approved by voters, still would fall far short of the $1 billion-plus that San Francisco's public works chief estimated is needed.

But, Lee said, it's "an important step toward fixing our streets, improving our streetscapes and creating a safer driving, cycling and pedestrian experience for all San Franciscans."

Of the approximately 865 miles of streets that run through San Francisco, officials say that more than half are deteriorated, pocked by potholes and buckling.

Tens of millions

Over the past five years, the budget for street resurfacing has averaged $42 million a year. Just to keep the streets from getting worse will cost an estimated $50 million annually over the next decade, officials estimate. To actually improve them would take at least $65 million a year, they say.

And, bond backers warn, the longer the work is delayed, the costlier the repairs.

Lee said that in a series of recent town hall meetings he convened in neighborhoods across San Francisco, a common demand - or plea - has emerged at each: "Mayor Lee, can we just fix the potholes?"

But turning complaints into voter support won't be easy.

"Infrastructure is not sexy," Ed Reiskin, San Francisco's public works director, said bluntly.

The proposed road repaving and street safety bond would need at least two-thirds approval to win - a high hurdle at a time when voters are keeping a close watch on spending.

Backers of the plan, however, stressed that the property tax rate would not be increased to pay off the debt because it would replace other existing bond burdens that are set to expire.

Voters rejected a similar $208 million bond measure in 2005, and the Board of Supervisors backed off a plan to put a bond for street improvements on the ballot last year when polling indicated insufficient public support.

Supervisors sign on

The first task now is to get the supervisors to agree to place the proposed bond measure on the November ballot. Supervisors John Avalos, David Campos, David Chiu, Eric Mar, Ross Mirkarimi and Scott Wiener have signed on as co-sponsors, enough to move the plan forward if none of them reverses course.

The next task is to drum up public support.

At a news conference Tuesday to announce the plan, the elected officials showcased community support they've lined up already, bringing out leaders from the city's bike and pedestrian advocacy groups, an advocate for disability rights and workers and union representatives who could benefit from the estimated 1,600 construction jobs in the private and public sectors that the public works projects would create.

But if any strong organized opposition emerges, securing the necessary two-thirds vote could be difficult, predicted Supervisor Sean Elsbernd, who represents the more conservative neighborhoods west of Twin Peaks.

Elsbernd, for one, doesn't back the bond proposal.

"Debt for ongoing finances is not prudent policy," he said. He said he probably could support a plan aimed at addressing the backlog of unmet street repairs, if a long-term financing plan was put in place in tandem.