Georgia's U.S. senators are citing a recent highway crash that killed five nursing students as they push the federal Department of Transportation to mandate new safety requirements for heavy trucks.

Republican Sens. Johnny Isakson and David Perdue sent a letter Thursday to Transportation Secretary Anthony Foxx asking the agency to finalize a rule requiring heavy tractor-trailers to use devices limiting their top speeds.

The Georgia State Patrol says a tractor-trailer on Interstate 16 slammed into traffic stalled by an unrelated wreck on April 22. The chain-reaction collision damaged seven vehicles and killed five nursing students from Georgia Southern University.

The senators' letter says the speed-limiter rule, under consideration since 2011, could have reduced the crash's impact and saved the lives of the five students who were killed.

Read the letter here [PDF].

Tags: I-16 Accident, Johnny Isakson, David Perdue