A highway patrol is either a police agency created primarily for the purpose of overseeing traffic safety compliance on roads and highways, such as the California Highway Patrol, or a detail within an existing local or regional police agency that is primarily concerned with such duties, such as the HWP units of Australian state police forces, or the New York City Police Department Highway Patrol.

Duties of highway patrols or traffic police include the following:

• Traffic enforcement: enforcing laws and regulations intended to improve traffic safety, such as speed limits
• Emergency response: securing the scene of a traffic accident by using cones and flares as well as providing first aid to the injured
• Accident investigation: gathering evidence to determine the cause of a roadway accident
• Commercial vehicle enforcement: enforcing highway laws related to commercial transport, including weight limits and hazardous materials rules
• General law enforcement: assisting local police, especially in rural areas, and keeping an eye out for non-traffic violations
• Maintenance: observing and reporting damage to the roadways, and conducting hasty road surveys after disasters or the passage of inclement weather
• Education: providing public information, handouts and displays to encourage safe driving and usage of the roads

Relation to State Police

Many state police agencies are, for historical reasons, referred to as a highway patrol organization. For instance, the California Highway Patrol is actually a state police agency, meaning that it is a police body having statewide authority to conduct law enforcement activities and criminal investigations. In addition to its highway patrol duties described above, it performs functions outside the normal purview of the city police or the county sheriff, such as enforcing traffic laws on state highways and interstate expressways, overseeing the security of the state capitol complex, protecting the governor, training new officers for local police forces too small to operate an academy, providing technological and scientific support services, and helping to coordinate multi-jurisdictional task force activity in serious or complicated cases. The California Highway Patrol also serves a bailiffs and courtroom deputies for certain state courts, such as the appellate courts. The fact that it is named the "California Highway Patrol" is due to the merger of the smaller California State Police with the larger California Highway Patrol and the combination of their functions into one agency.

See also

• Park ranger
• State police
• California Highway Patrol
• New York City Police Department Highway Patrol
• Florida Highway Patrol
• Philadelphia Highway Patrol
• South Carolina Department of Public Safety