The National Transportation Safety Board recommended improved safety features on trucks and buses in the wake of this month's bus crash in New York City that left 15 people dead.

In testimony before a subcommittee of the U.S. Senate Committee on Energy & Commerce on Wednesday, NTSB Chairwoman Deborah Hersman described the events of the March 12 crash in the Bronx. Hersman told the panel that the bus, which was traveling at nearly 78 mph at the time of the crash, veered off the roadway and struck a roadside barrier. The roof of the bus was severed in the crash.

Based on this and previous crash investigations, NTSB recommended safety measures such as improved roof strengths, redesigned emergency exits and new standards for passenger seating. The NTSB is also recommending government oversight of tour buses to ensure vehicle safety.

The NTSB will be holding a public forum on May 10-11 to discuss improved truck and bus safety, Hersman said.