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Higher And Smoother I-275 Coming Soon

Tribune photo by SCOTT ISKOWITZ

The new lanes will loom over the old southbound lanes, which won't be rebuilt for several years.

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By RICH SHOPES | The Tampa Tribune

Published: December 14, 2008

TAMPA - Driving on Interstate 275 through downtown Tampa is a little like riding a roller coaster – up one moment and down the next without really knowing what's over the next hill.

But that thrill ride is about to come to an end.

Tons of fill dirt are being used to lift the new lanes by as much as 20 feet and create an even path between the interchanges where the road crosses over Dale Mabry, Himes, Howard and Armenia, and eventually West Shore and Lois when the next phase of construction is finished.

The reason is safety.

"This will give you a nice, long sight distance to react to any slowed traffic or traffic jams ahead," Department of Transportation spokesman John McShaffrey said.

When the first phase between Himes and Ashley is finished in late 2009 or early 2010, the four new northbound lanes will be 5 to 20 feet above the existing road surface. At cross streets, the bridges will be 5 to 7 feet higher than the bridges now being used and have an extra two feet of clearance below.

The highest point, near Howard and Armenia avenues, will be 26 feet higher than the surface below. The new lanes will loom over the old southbound lanes, which won't be rebuilt for several years.

Safety is reason

This same design, using fill dirt to create an elevated road, was used 10 years ago when Interstate 4 was reconstructed.

"The whole issue of sight distance is much more of a concern than it was 50 years ago or even 30 years ago because of travel speeds and volumes," said Ken Kobetsky, program director for engineering at the American Association of State Highway and Transportation Officials in Washington, D.C. "There's a direct relationship between improving sight differences and driving safety."

In I-275's case, the peaks and valleys date to the 1950s when the original highway was designed. Partly to save money and because of design standards and lower traffic volumes, the highway was designed with inclines at the cross streets.

The road was widened in the mid-1970s, but the inclines, which reach as high as 15 feet, remained. The result, even today, is a succession of ups and downs that keep drivers from knowing whether traffic ahead is flowing smoothly at the same speed, or at a standstill.

"Couldn't see"

Ed Ham of Temple Terrace knows all about those challenges.

In October 2007, Ham and his wife were heading home from work in St. Petersburg when they drove their Toyota Corolla over the Lois Avenue hill and suddenly came face to face with a traffic jam.

"We hit our brakes fine, but then we got hit from behind. It gets a little dicey around there," said Ham, a claims adjustment manager at Allstate Insurance.

Four cars were involved in the crash. The Hams avoided injury, but a driver behind them was rear-ended and hurt.

Ham's explanation for the pileup: "You couldn't see over the next hill."

The problem seems to be worse in the afternoons, he said. Even though Ham frequently checks traffic reports before leaving work, backups on the highway are almost impossible to predict, making every drive home a guessing game.

Police can't say how many accidents are attributable to the peaks and valleys. About 175,500 vehicles a day travel I-275 between the Howard Frankland Bridge and Ashley Drive, making it the second most traveled stretch in Hillsborough.

"Interstates are supposed to be designed for free flow of traffic over long distances," Florida Highway Patrol Trooper Sgt. Steve Gaskins said. "What has happened here is I-275 has become an urban traffic pattern instead a long-distance traffic pattern, with a lot of entrances and exits."

Once the $107 million northbound Himes to Ashley Drive construction is finished, the DOT will reconstruct both sides of I-275 between Himes and just north of the Howard Frankland Bridge.

That project is expected to begin in early 2011. After that, the southbound lanes from Himes to the Hillsborough River will be rebuilt.

Reporter Rich Shopes can be reached at (813) 259-7633.

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