Talmedge, who said he didn't know anything about the road restrictions, said Jackson also drives a school bus. No one answered the phone Sunday at a number listed for Jackson in Philadelphia.
Neither federal nor Pennsylvania state records show crashes involving Calvary Coach over the past two years or complaints filed against the company.
The Facebook page of the Destined for a Dream Foundation said the trip to Harvard was to "visit the campus, sit with the office of cultural advancement, followed by a tour of the campus ... followed by Harvard Square (shopping, eating, site seeing...etc...) This should be a fun time for all!"
Transit officials sent buses to pick up other passengers and get them out of the frigid temperatures.
The accident caused only cosmetic damage to the bridge and road, state police said. The road was reopened Sunday.
The crash recalled a similar accident in Syracuse, N.Y., in 2010 when the driver of a double-decker Megabus missed his exit and was using a personal GPS to find the bus station. He passed 13 low-bridge warning signs, some with flashing yellow lights, before hitting an overpass. Four people were killed. The driver was acquitted of homicide charges.
In December, a driver who prosecutors said was nearly asleep at the wheel was acquitted of the most serious charges in a crash that killed 15 gamblers returning to New York City from a Connecticut casino in 2011.
Federal officials stepped up enforcement of bus safety regulations last year, closing more than two dozen operations that mostly ferry passengers in the busy East Coast transportation corridor. It was the largest single federal crackdown on the industry.