Pittsburgh Mayor Luke Ravenstahl worried that he might be violating union rules as he climbed up on a city paver yesterday to ceremonially launch the asphalt season.

He was assured that he was not. But he asserted that he was breaking with a recent tradition of spotty attention to road quality.

"Last year we did 39 miles of road," the mayor said, prior to sitting in the passenger's seat of the paver. "This year we'll do at least 51 miles of road."

That's short of the 80 miles the city ideally should be paving annually to meet standards. "I'm not going to sit here and say that we can get to 80 miles a year, because that's not realistic," Mr. Ravenstahl said.

This year's 51-mile level is one the city can sustain and perhaps improve upon, the mayor said, after years of up-and-down mile counts. It's also a response to what he perceives as a worsening pothole problem. The Department of Public Works patched 13,000 potholes in the first three months of this year, which is double what it did last year -- a result, the administration argued, of both greater diligence and more holes.

The city's capital budget includes $10 million for paving.

Each of the five major public works divisions will see around 10 miles of paving, said Public Works Director Guy Costa. The decisions on what to pave were made based on ratings of street conditions, weighted according to traffic levels, he said.

Starting next year, the city will use software provided by CarteGraph Systems, a firm based in Dubuque, Iowa, to objectively choose streets based on their condition, history, surface, age, traffic volume and damage from utility work. Mr. Ravenstahl said the computer system would "assist us in picking the roads, in an attempt to remove the political ramifications or influences in the paving process."

The process that led to a $35,000 contract with the firm started after the Pittsburgh Post-Gazette reported that streets in front of, or next to, the homes of four council members and 46 Democratic Committee members made last year's paving list.