Pittsburgh's pervasive pothole problem has its roots in decades of neglect as financial problems and other priorities caused the city to fall far short of the paving needed to keep the roads in good repair.
With 866 lane-miles of asphalt streets, the city would need to pave about 80 miles each year to maintain the roads in good condition. It hasn't done that since 1999 and often has fallen well short of that threshold.
The city budgeted $9.8 million for resurfacing and paved about 50 miles of streets last year. This year's capital budget allocates $7.1 million, or nearly 28 percent less. As a result, it expects to pave only 28 or 29 miles, said Guy Costa, chief operations officer.
Sixty miles of streets were paved in 2012, the most since 1999. In the five years before that, it averaged fewer than 40 per year.
"In an ideal world, you'd want to do 80 miles," Mr. Costa said. With its financial limitations, "it would be great if Pittsburgh could get to 60."
According to news accounts, when Richard Caliguiri ran for his first full term as mayor in 1977, he had 117 miles paved and did another 90 the following year. It became part of the city's political lore that he had paved his way to that first election victory. In the decade preceding that blacktop binge, the city had averaged 28 miles per year.
More recently, the city mostly has chosen a road to ruin. After hitting the 80-mile standard in 1999, it did less and less until reaching a low of 24 miles in 2004.
The city's website estimates that the need to repave a street occurs every 10 to 12 years. When pavement gets older, it is far more susceptible to cracking that allows moisture to penetrate. Freezing and thawing causes expansion and contraction that crumbles the asphalt.
"Water's a big factor," Mr. Costa said. Vehicle weights, traffic volume and the condition of the base below the asphalt also factor in. On some streets, asphalt was placed atop old brick and cobblestones; on others, on top of dirt, he said.
Since taking office in January, Mayor Bill Peduto has ordered two all-out blitzes on potholes, including one that began last week and continued Monday with 15 crews on the job.
"I don't remember a time when there have been so many potholes over such a big area," he said as he helped public works crews fill holes Saturday.
Progress was evident in a 32-mile tour of streets taken by the Pittsburgh Post-Gazette on Monday, but some streets remained riddled with craters.
The worst street encountered during the tour was Edgebrook Avenue in Brookline, which looked like it had been strafed by bombers.
Brookline Boulevard, cited as one of the worst before the latest blitz, was much-improved Monday -- still bumpy and rough but without the axle-bending holes that existed before crews attacked it over the weekend.
The city gave up trying to patch Negley Run Boulevard in Larimer, milling it down to its concrete base until it can be resurfaced in the spring. It planned to do the same today on a section of Collins Street that intersects with Negley Run.
Several potholes were patched on Penn Avenue in Garfield, but other giant ones remained, and a driver needed to keep a wary eye on Penn all the way to the Strip District. Potholes also remained on Bausman Street in Knoxville; South 18th Street on the South Side; Centre Avenue in Shadyside; Gross Street in Bloomfield; Evaline Street in Bloomfield and Garfield; Baum Boulevard, Penn Circle and Whitfield Street in East Liberty; and Chestnut Street and Ridge Avenue on the North Side.
Drivers on West Carson Street in the Pennsylvania Department of Transportation's work zone between McKees Rocks and the West End Circle, had been unable to avoid huge potholes because the road is hemmed in by concrete barriers. Over the weekend, crews repaved several sections using hot asphalt, which is longer-lasting than the cold mixture being used by city workers.
Jon Schmitz: email@example.com or 412-263-1868. Visit the PG's transportation blog, The Roundabout, at www.post-gazette.com/Roundabout. Twitter: @pgtraffic.