Washington — Some lives lost in the Atlanta crash of a bus carrying an Ohio baseball team may have been spared if safety recommendations made eight years ago had been heeded, the chairman of the National Transportation Safety Board said Tuesday.

"Although this accident occurred only 18 days ago, we know from past experience that one of the major issues is likely to be the crash worthiness of the motor coach," Mark V. Rosenker told the House Transportation Subcommittee on Highways and Transit Motor Coach Safety. Faulty highway design may also have been a factor, he said.

Seven people died in the accident, including five students, the bus driver and his wife.

Rosenker testified that some of the occupants were ejected or partially ejected from the vehicle. "We know from past investigations that keeping occupants within the vehicle is paramount to their protection," he said.

In 1999, his agency urged the National Highway Traffic Safety Administration to adopt several measures to protect the occupants of motor coaches, Rosenker said. These included stronger bus roofs, protective window glazing or shatterproof windows that prevent occupant ejections, easy-to-open window and roof emergency exits and protective systems that better shield occupants in side impacts and rollovers.

None of these recommendations have been implemented, Rosenker said.

Although his agency's investigation of the March 2 bus crash has not advanced far enough to draw conclusions yet, he said, the need for these safety measures have been shown in similar accidents investigated in the past.

Outside the hearing room, Rosenker promised that "there will be no shortcuts" in his agency's investigation of the Atlanta crash where early blame has been pointed toward a confusing left-hand exit from a HOV lane on I-75.

However, if some "glaring" safety defect is discovered before the investigation is complete, "we will make an urgent recommendation" on fixing it immediately, Rosenker said.

Such a "glaring" defect could include a faulty highway design, he said in answer to a question. Highway engineers will be part of the NTSB investigating team.

In the predawn crash, a chartered bus carrying a baseball team from Bluffton University in Ohio to a tournament in Florida plunged off an overpass onto the expressway below. The subcommittee called the oversight hearing on motor coach safety in the aftermath of the Atlanta crash and other fatal bus accidents, including the 2005 tragedy near Houston where 23 elderly occupants died in a bus fire during their evacuation from the path of Hurricane Rita.

The Atlanta crash is still being examined, witnesses said.

"Preliminary investigations seem to indicate that the motor coach driver mistook a High Occupancy Vehicle exit ramp for a traffic lane and did not stop at the top of the ramp," testified John Hill, head of the Federal Motor Carrier Safety Administration.

Hill told the subcommittee that the Executive Coach Luxury Travel Inc. bus involved in the crash had been inspected one week before the accident by the Public Utility Commission of Ohio.

No vehicle violations were found and the preliminary investigation shows the driver did not violate regulations for total hours of service, he added. The driver who was killed relieved the previous driver and boarded the bus at about 4:30 a.m., one hour before the crash.

The HOV lane exit was also criticized by Jaqueline Gillan, vice president of Advocates for Highway and Auto Safety, a coalition of consumer, insurance, medical and safety groups that lobbies for state and federal policies promoting safer streets and motor vehicles.

"There are major issues involving highway design in this crash, including a left hand exit lane with inadequate signing," testified Gillan. She also said the "bridge parapet was incapable of restraining a heavy commercial vehicle."

She also criticized federal inaction on making buses more crash worthy. Occupants were ejected through side windows and the windshield in the "horrific" Georgia crash due to safety deficiencies that should have been corrected after the 1999 recommendations.

Under questioning by subcommittee chairman Peter DeFazio, D-Ore., Rosenker said research is not conclusive on whether seatbelts might have saved lives or prevented serious injuries in such bus crashes.

"The jury is still out," he said. While seatbelts are known to save lives in cars, the "larger compartment" of a bus has different dynamics and may need different features, he explained.

For certain, he said, it would be hazardous to "retro fit" buses with seatbelts. He said airbags, including on the sides of the buses, may prove to be a better safety solution.

"In addition, the vehicle itself must be strong enough to prevent intrusion into the occupant compartment," he said. "Finally, the seats, side panels and other surfaces need to absorb energy when impacted by occupants in the crash scenario. When all these concepts work together, it greatly increases the occupants' chance of survival."

Rosenker said his agencies recommendations to achieve these protections have not been implemented.

"Surviving an accident depends on many factors," he concluded. "The structural integrity of the vehicle and passenger compartments, seat design and restraint systems can all increase a person's likelihood of surviving a crash."