As though arriving in Philadelphia by the back door could get any drearier.

Long-running construction on the Platt Bridge, now eight months behind schedule, has managed to add an automotive thrill ride to a familiar eyesore.

The $43 million painting and reconstruction of the 61-year-old bridge gives the city's grimy industrial gateway from Philadelphia International Airport a gloomy and treacherous centerpiece.

Arching over sprawling oil tanks and the steaming stacks of the Sunoco refinery, the bridge begins in weeds and ends by a junkyard, as it has for decades. But now, it also is laced with concrete barriers funneling traffic into two lanes (from four), and it's topped by a plastic shroud covering a dark, noisy construction zone.

For motorists, a trip over the George C. Platt Memorial Bridge is a challenging maze of orange barrels, detour signs, flashing speed monitors, tailgating cabs, and shadowy crews working in the murk of the shroud.

Welcome to Philadelphia.

"It's ridiculous," said taxi driver Muhammad Chughtai. "You have little, tiny one-way lanes, and if you stray a little to the right or left, you hit the barrier and have an accident. It happens almost every day."

Chughtai, 55, of Northeast Philadelphia, said he and a passenger were stuck for five hours after such an accident.

And on days when the Phillies play or other events attract crowds to South Philadelphia, traffic jams on the Platt can seem unending.

Tourism officials have long lamented the first impression created by this entrance to the city over the industrial mouth of the Schuylkill.

"There are certainly different ways that people drive visitors to and from the airport that better show off the city," said Danielle Cohn, vice president of marketing for the Philadelphia Convention & Visitors Bureau. "We're all about showing Philadelphia in the best light."

Most drivers prefer the slightly longer, less dismal trip on Interstate 95 over the double-decker Girard Point Bridge, which also is still under repair. But many take the Platt because it's a shorter trip to Center City and the Schuylkill Expressway.

"It's faster, except when there's an accident," said cab driver Tam Gidey, who often makes the trip from the airport. "Then, you can be there an hour."

More than 50,000 vehicles a day use the 1.7-mile-long Platt Bridge, which carries Penrose Avenue (Pennsylvania Route 291) over the Schuylkill. That's even without trucks and buses, banned in May because of the construction.

Those 50,000 drivers must co-exist with crews sandblasting and repairing the steelwork, replacing expansion joints, repairing concrete piers, replacing guardrails, putting down a new concrete road surface, and repainting the bridge.

The construction, originally scheduled to be completed by October 2013, is now set to be finished in June 2014. The Pennsylvania Department of Transportation pushed back the deadline after finding more work was needed on the bridge approach structures.

Current lane restrictions must be removed by the new deadline, or the contractors will face $30,000-a-day penalties.

With traffic now limited to one lane in each direction, the speed limit on the bridge has been reduced to 35 m.p.h. from the normal 45, but flashing roadside speed monitors show many cars still zip through the narrow chutes at 50 m.p.h. or faster.

"It has been an ongoing issue, and we have been working with PennDot to try and make it safer for drivers, because drivers seemed confused," said Rina Cutler, the city's deputy mayor for transportation. She said PennDot had responded well to the city's safety concerns with "continual adjustments."

"We need motorists to be cautious," said Harold Windisch, senior assistant construction engineer for PennDot. "They just have to go slow. We've done everything we can to slow them down."

This is the third major repair project on the bridge since 1984, but it's the most extensive, said Chuck Davies, PennDot assistant district executive for design. This time, extensive steel repair is being done and the entire bridge is being repainted.

"This is more about making sure it doesn't fall into the [structurally deficient] category," Davies said.

Pennsylvania leads the nation in structurally deficient bridges, with 4,800 of the 25,000 state-owned bridges in that condition. The designation means those bridges have serious deterioration in at least one of their three primary components: deck, superstructure, or substructure.

Such bridges are not unsafe, but they need prompt repair work.

The Platt Bridge is not structurally deficient, though it is getting close, according to recent inspections.

On a scale of 0 to 9, a 4 ("poor") for any of the three primary components would move it into the structurally deficient category. The deck and superstructure of the Platt are rated 5 ("fair"); the substructure is rated 6 ("satisfactory").

Inspectors also measure bridges with a "sufficiency rating" on a scale of zero to 100, using a formula that evaluates safety, serviceability, and how essential the bridge is. Anything below 50 means a bridge is in poor enough condition to qualify for federal money for repair.

The Platt has a sufficiency rating of 43. So 80 percent of the cost of its repair will come from the federal government, 20 percent from the state.

The bridge also is deemed "functionally obsolete" because of its age, design, and narrow lanes. That is not a measure of its safety.

Opened in 1951 as the Penrose Avenue Bridge, the span cost $13 million to build.

It was renamed in 1979 to honor a 21-year-old Irish immigrant who, as a private in the Union Army, rescued his cavalry unit's colors during a bloody fight on the fringes of the Battle of Gettysburg in July 1863. George Crawford Platt received the Medal of Honor in 1895 for his Civil War heroism.

After the war, Platt lived in South Philadelphia, working as an engineer, and he is credited with building the original Penrose Avenue Bridge that was eventually replaced by the current span.

Platt was honored, briefly, with bronze bas-reliefs of his likeness that were mounted on poles at each end of the bridge in 1986. Both were promptly stolen.

In August 1975, when the Platt was still the Penrose, the bridge was closed for hours during one of Philadelphia's deadliest fires, at the refinery below. The blaze, which killed eight firefighters, threatened the bridge and a nearby smokestack, which officials feared might collapse onto it.

When the current construction is complete, the repainted Platt will be a medium blue similar to its current color.

The shroud that envelops a 700-foot section of the bridge is necessary to contain paint spray and fumes, PennDot officials said. It is expected to be removed from over the road by the end of this year, though it will remain beneath it for the duration of the project.

Although PennDot had hoped to keep the bridge sidewalk open throughout construction, the walkway was closed in May. The construction contractors agreed to spend $3,000 a week to provide a shuttle van to carry pedestrians across, 24 hours a day, seven days a week.

The shuttle service has not been in great demand: It has carried 40 passengers, including 13 bicyclists.

The walkway is expected to reopen by October, PennDot spokesman Gene Blaum said.

The Platt job is a joint venture of Hercules Painting Co. Inc. of New Castle, Pa., and Vimas Painting Co. Inc. of Lowellville, Ohio.