The New York City Police Department Highway Patrol is a specialized unit under the auspices of the NYPD's Transportation Bureau primarily responsible for patrolling and maintaining traffic safety on limited-access highways within New York City. The NYPD Highway Patrol's other duties and roles include collision investigations, advanced driver and radar training for NYPD officers, field sobriety testing, dignitary and parade escorts, hazardous material and truck traffic enforcement, anti-drag racing programs, and anti-terrorist checkpoints at key bridges and intersections in the city.