A three-time officer of the year with the Maryland Transportation Authority police was killed yesterday morning when a pickup truck smashed into his patrol car on the shoulder of Route 50, police said.

Officer Duke G. Aaron III, who won the award in 2001, 2002 and 2003 for his work patrolling the Chesapeake Bay Bridge, suffered massive head injuries and internal trauma in the crash, which occurred about 10 a.m. in Anne Arundel County.

Aaron, 29, was taken by helicopter to the Maryland Shock Trauma Center in Baltimore, where he died in the early afternoon, police spokeswoman Catherine Leahan said.

"This is a major, huge blow for us," Leahan said.

The driver who allegedly hit Aaron's car also was taken to the hospital with injuries that did not appear to be life-threatening, she said.

After the crash near Saint Margarets Road, all westbound lanes of Route 50 were closed for 31/2 hours -- creating a 10-mile traffic jam that extended over the Bay Bridge and past Stevensville on Maryland's Eastern Shore.

A highway administration spokesman said it was one of the state's farthest extending backups in recent memory that did not involve weekend beach traffic.

Police said that Aaron had issued a citation to a driver just before the crash. After that driver drove on, Aaron returned to his parked cruiser to complete paperwork on the citation.

As he sat on the right shoulder of the westbound lanes, police said, a 1998 Dodge Ram pickup truck ran into the back of the unmarked cruiser at high speed.

Police sources familiar with the case identified the pickup's driver as Albert Gene Antonelli, 32, of Queenstown, Md.

Antonelli was driving on a suspended license, police sources said.

He was charged with traffic violations last year that included driving on a suspended registration. He failed to appear in court on that charge and several others, including failing to display a registration card and making an improper turn, court records show.

Antonelli pleaded guilty to negligent driving in 2002. He also has been arrested on drug possession charges several times, court records show. He pleaded guilty to possessing drug paraphernalia in 2002 and was sentenced to probation, court records show.

It was the second time in recent months that a police officer was killed in a traffic accident on Route 50. On May 9, Maryland State Police Trooper 1st Class Anthony Jones, 50, was struck and killed in Prince George's County as he crossed the highway on foot to remove accident debris.

Aaron was with the Transportation Authority police force for 10 years. The authority, with a force of about 450, patrols bridges, tunnels, Baltimore-Washington International Airport and the Port of Baltimore.

He was the fourth transportation police officer to be killed on duty and the first since 1991, when a car struck an officer on the Bay Bridge.

Aaron was remembered yesterday as one of the department's rising stars. Chief Gary W. McLhinney said Aaron was the top-performing officer at the Bay Bridge, writing more tickets and conducting more investigations than any of his colleagues.

He said that Aaron recently climbed out onto the bridge to rescue a woman who was threatening to commit suicide by jumping.

"He was just an outstanding police officer," McLhinney said. "He's the kind of guy you'd want as your own son."

Aaron was married and lived in Pasadena, police said.

Staff researcher Bobbye Pratt contributed to this report.