The nation's largest police unions and a national coalition of police chiefs agreed Thursday to mandatory use of body armor and seat belts for all law enforcement agencies.

The accord, the first of its kind between labor and law enforcement leaders, comes amid persistent reports that large numbers of officers die in shootings and traffic accidents without the basic protection afforded by bulletproof vests and seat restraints, USA Today reports.

Although traffic-related incidents were the leading cause of officer deaths in 13 of the past 15 years, according to the National Law Enforcement Officers Memorial Fund, which closely tracks police fatalities, about half of officers do not regularly wear seat belts.

During the past three decades, 42% of police killed in auto accidents were not wearing seat belts, according to a National Highway Traffic Safety Administration review. Law enforcement estimates of seat belt compliance hover around 50%, well below the 86% rate of compliance among the general public.

In fatal shootings, 36% of officers killed from 2003 to 2012 were not wearing body armor, according to FBI statistics.