ATLANTA -- State Department of Transportation work crews scrambling to complete repairs on nearly 170 bridges across Georgia will have all but about 40 finished by tomorrow, when new weight restrictions take effect, DOT officials said yesterday.
The new requirements are based on federal guidelines for calculating bridge weight capacity. Truckers must now watch for signs on substandard bridges limiting the allowable weight until those bridges can be shored up.
The affected bridges were built 30 to 50 years ago, well before the Arab oil embargo of the 1970s resulted in lower speed limits, said Bill DuVall, the DOT's bridge inspection engineer. That, in turn, prompted trucking companies to start hauling bigger loads, including the tandem trailers that have become so prevalent today.
"They [the bridges] were originally designed for 15-ton vehicles," DuVall said. "But because we slowed the traffic down, we had to increase capacity of trucks. We never went back, so now trucks are at 80,000 pounds [or 40 tons]."
The bridges were built using H-shaped, 10-inch steel piles, which don't meet federal safety standards. The DOT decided to do the upgrades after the Federal Highway Administration recommended that all states evaluate the safety of their bridges and make repairs necessary to bring them into compliance.
DuVall said the work involves adding lateral supports to some bridges and strengthening the existing piles of others by adding steel cover plates.
DOT spokeswoman Jilayne Jordan said more than 100 of the affected bridges had been upgraded as of June 24, the last time the list was checked, with the agency using a national map of truck routes to prioritize the projects. …