TAMPA — Get ready for Tampa’s own mini Carmageddon, the closing of the Platt Street Bridge.

When the 85-year-old drawbridge leading downtown closes for repairs in the wee hours Monday, the disruption will spare no one.

Not commuters, nor hockey fans, nor Tampa General Hospital employees nor Davis Islands residents, including the mayor.

“I’m sure I’ll have my opportunity to sit in traffic, like everyone else,” Mayor Bob Buckhorn said.

But unlike the original Carmageddon, which shut down a major Los Angeles freeway for one weekend this summer, the Platt Street Bridge will stay closed for more than three months, until mid-January.

The one-way bridge carries 34,000 cars and trucks a day from Bayshore Boulevard directly into downtown Tampa.

It’s a major commuter route not only for South Tampa residents, but for many Pinellas County commuters who come over the Gandy Bridge and drive up through South Tampa. It carries more traffic than can be detoured onto any one other road.

It was built in 1926 and is showing its age. Its concrete is crumbling, its gears are rusty and its electronics are out of date.

Designed by the same firm that created the Golden Gate Bridge, the 518-foot bridge was designated a historic structure in 2006.

Because of its age, many gears and motors had to be custom-made or machined. So county officials did not set the date of the closing until every replacement part had been fabricated, delivered and tested.

When finished, it will look just like the original, down to the color of the paint.

The rehabilitation job will cost $13.8 million, but the county has given the contractor incentives to finish early. It will receive $10,000 a day for every day it finishes before Jan. 16. Every day that it is late, the contractor will be penalized $10,000.

“It’s such a critical artery,” Hillsborough County Public Works Department spokesman Steve Valdez said. “We wanted to make darn sure we lessened the amount of adverse impact as much as we possibly could.”

The work is being done now partly to be completed before next year’s Republican National Convention, scheduled Aug. 27 to 30.

In the meantime, officials plan to post police officers to direct traffic at three choke points. They are encouraging motorists to plan ahead. Take another route. Come in a little earlier or a little later.

Coming from South Pinellas? If you drive over on the Gandy Bridge, consider taking the Lee Roy Selmon Expressway instead of Bayshore Boulevard. (You’ll still have to pay the tolls. All expressway revenue is pledged to repay bonds, and the only time tolls are waived is in an emergency evacuation.)

Otherwise, officials say, skip the Gandy and consider the Howard Frankland Bridge.

That’s right: the Howard Frankland. When that’s considered a preferred commuting alternative, “you know that pickings are slim,” Tampa transportation manager Jean Dorzback said. But she said there are “only so many ways to go.”

Perhaps no one will be more inconvenienced than the 5,500 residents of Davis Islands, a 1,700-home suburb connected to Bayshore Boulevard by a single bridge, and the largest employer on the islands —Tampa General Hospital.

“We are very concerned about it,” said architect Antonio Amadeo, the traffic and safety chairman of the Davis Islands Civic Association. He estimates that the tie-ups could add 10 to 30 minutes to trips residents make to and from the islands.

Then there’s Tampa General, with nearly 7,000 employees and more than a thousand beds. Still more patients come for out-patient procedures. Shuttles carry hospital employees to and from remote parking lots across the bridge.

“We think it’ll have a major impact on us,” hospital spokesman John Dunn said. While there might be delays in the morning, “I think our bigger concern is leaving the hospital at the end of the day.”

The day shift at Tampa General runs from 7 a.m. to 3 p.m. From 3 to 5 p.m., 1,500 cars typically leave the hospital, and a traffic delay in downtown Tampa can ripple back onto the islands.

In May, for example, the St. Pete Times Forum hosted a weekday graduation ceremony for the University of South Florida.

“We had people stuck in our garage who couldn’t even move for 45 minutes to an hour,” Dunn said.

Officials expect ambulances to hit fewer delays going to the hospital than leaving to return to service. If that happens, Hillsborough County Fire Rescue plans to shift other ambulances around to make sure that the county is covered, Fire Rescue spokesman Ray Yeakley said.

At the St. Pete Times Forum, the Tampa Bay Lightning hired its own traffic engineer to help design traffic and parking plans for the arena’s home games. It will post travel tips for fans on its website and call or send e-mails to season ticketholders.

City and county officials generally say they expect several rough days, maybe even a couple of difficult weeks, but eventually drivers should find their way and things will settle down.

At a community meeting on Davis Islands Tuesday night, residents said local officials had improved the traffic management plan and praised plans to close northbound Bayshore at Swann Avenue. (Southbound traffic, like from the Publix at Bayshore and Platt, will continue to flow.)

But while school district officials have been involved in planning meetings, several Davis Islands residents said their school administrators didn’t seem to know enough about the closure. Kids delayed by traffic, they worried, might be penalized for being late.

In response, Hillsborough County Commissioner Sandra Murman said she would talk to school administrators and ask them to be lenient with tardiness during the first days after the bridge closes.

But she also encouraged residents to spread the word, so that fewer drivers are caught by surprise on Monday.

“We will defuse as much chaos as we can,” she said. “Tell your neighbor. I think people are not tuned into this at all yet.”

To learn more Visit www.hillsboroughcounty.org/publicworks/traffic/platt or call (813) 635-5400 for information about the construction project or (813) 274-8333 for information on alternate routes.