Delayed by a harsh winter, highway construction crews have returned with a vengeance to Philadelphia-area roadways, causing congestion even as they work to ease it.

For drivers, the busy construction season means delays, detours, and gridlock. Some are pioneering new commutes to avoid roadwork, and delivery drivers are regularly recalculating their routes to dodge clogged arteries.

Big projects include the widening of New Jersey's toll roads and the construction of a nine-mile-long parkway in Bucks and Montgomery Counties.

The good news is that the repainting and rebuilding of the Girard Point Bridge on I-95 in South Philadelphia is well ahead of schedule and likely to be done this year. The bad news is that crews will start a $43 million repainting project on the nearby Platt Bridge any day now.

"In many respects, this is a 'no pain, no gain' situation," said Jim Lardear, director of public and government affairs for AAA Mid-Atlantic. "The construction, delays, and immediate frustration it causes are a hassle, but it is necessary to maintain our safety and mobility in the long run."

"We have to get on the highways and bridges to fix them," said Eugene Blaum, spokesman for the Pennsylvania Department of Transportation's five-county southeastern district. "We try to minimize impacts as much as possible. That's why we do so much work at night. And we try not to do a lot of work during rush hours."

Low temperatures last winter postponed work that could have spread the pain over a longer period, Blaum said. Now crews are scrambling to get as much done as possible during the summer months.

PennDot has more than 100 projects under way in the Philadelphia region, and 60 bridges are being rehabbed or replaced. Crews are struggling to keep up with deteriorating spans, as about 6,000 of the state's 25,000 bridges are structurally deficient, the most in the nation. (Structural deficiencies mean that a bridge needs repair, not that it is unsafe.)

"We are bustling in South Jersey this summer," said Joe Dee, spokesman for the New Jersey Department of Transportation. "We will be doing the work with an eye toward keeping people on the move."

Though the region is humming with roadwork, it is not quite as busy as in 2009, when federal stimulus funding boosted construction. This year, PennDot is spending about $400 million on highway projects in Southeastern Pennsylvania, down from about $650 million two years ago.

For drivers such as Silvia Hablak, a visiting nurse who travels about 300 miles a week for work, road construction means late appointments and frequent frustration.

"On Friday, I was on I-295 to go see a client. . . . What usually takes five minutes took an hour," said Hablak, of Cherry Hill. Another trouble spot, she said, has been the intersection of Routes 70 and 73 in Marlton, where crews are replacing a traffic circle with an overpass.

For Matthew Gurski, who travels between his old home in Hazleton, Pa., and his new one in Palmyra, construction on the Northeast Extension of the Pennsylvania Turnpike is a regular annoyance.

"They're doing the Lehigh Bridge up there, but you hit it everywhere. In Hazleton, they've been widening the main road for three years," said Gurski.

Briana Gray of Haddon Heights said she was stuck in traffic on I-295 near Exit 26 on Tuesday night at 11.

"There's usually never traffic late at night, but it was backed up for two miles," Gray said.

Work zones can be dangerous as well as annoying.

Nationwide, an average of 13 people a week die in work-zone crashes, and nearly 85 percent of them are drivers or their passengers, according to AAA's Lardear.

Besides the state agencies, towns and counties have road crews out on smaller projects that tie up traffic.

Montgomery County is planning its first major paving projects in three years, with work scheduled for Ridge Pike, Easton and Knight Roads, and Swamp Pike, said Donald A. Colosimo, county director of roads and bridges.

"The last couple of summers we scaled back paving in light of the economy, but this year we felt we really had to do something," he said. "We have six or eight roads that have been needing work for some time."

Contact staff writer Paul Nussbaum at 215-854-4587 or pnussbaum@phillynews.com.