BALTIMORE -- A federal investigative team will close down Interstate 895 on Saturday afternoon to retrace the path of a tanker truck before it plunged from an overpass onto Interstate 95, sparking an explosion and killing four people.
A team of investigators from the National Transportation Safety Board will use a similar, but empty, tanker truck to conduct the site test between noon and 5 p.m., spokesman Ted Lopatkiewicz said Friday.
"This is a method we use to help document the movements of the accident vehicle," he said. "This is necessary."
Meanwhile, Rita A. Gall, 42, of Lansing, Mich., was the third person identified and the driver of a tracker trailer. She worked for Swift Transportation Co. in Greer, S.C. Officials at the company's headquarters in Phoenix did not immediately return telephone calls from The Associated Press on Friday.
To determine if the tanker had any mechanical problems, investigators will map the path of the tanker truck by "matching the vehicle to the marks" on the road, Lopatkiewicz said. The team has measured 165 feet of tire marks before the truck turned over the jersey barrier, landing on I-95 with a full load of gasoline in its tank.
In matching the marks on the interstate to the dimensions of the tanker, investigators can animate the accident on a computer, he said.
"It's part of the overall investigation," Lopatkiewicz said. "Every piece of information we get fills in a hole here and there."
The NTSB often recreates accidents during investigations, he said.
Two more agencies - the Federal Highway Administration and the National Highway Traffic Safety Administration - will help the NTSB with the investigation.
Jackie M. Frost, 64, of Finksburg was driving a 2003 Freightliner Daytripper model tractor and a 2000 Heil 406 model tanker. He was working for Petro-Chemical Transport Inc., which is based in Addison, Texas.
Maurice Durschlag, 62, of Glen Burnie was the driver of the pickup truck involved in the accident. The driver of a car has not yet been identified by police.
The tanker had about 8,900 gallons of gasoline in its 9,200 gallon tank at the time of the accident. The U.S. Transportation Department says tankers can carry a maximum of 99 percent of their capacity of flammable liquids and regulates the weight of tankers.
In comparing the tanker to a bottle of soda, "you don't fill it to the very cap," said John Conley, vice president of National Tank Truck Carriers. "You would see a lot more movement of the liquid if it's half loaded."
Frost's cargo of gasoline may have shifted, making the vehicle uncontrollable, police have said. Two witnesses saw the tanker moving erratically on Interstate 895 before Tuesday's crash.
Lopatkiewicz said gasoline will not be in the tanker during the accident recreation, with weight not be important.