Coil of wire embedded in the roadway used to detect vehicle volume/presence. This data enables a traffic signal to function more efficiently, programming changes from red to green based on demand. Also used to control ramp meters.

A free phone service that provides real-time traffic and travel information 24 hours a day, seven days a week. Works on all cell phones and land-line phones.

Designated areas away from the travel lanes to be used for temporary parking of damaged vehicles, filling out forms after an accident has occurred, emergency repair of disabled vehicles, issuing citations, etc. The purpose of these areas is to reduce "rubbernecking" and to provide a safe refuge for persons investigating an accident.

A major highway primarily used for through traffic and usually on a continuous route; it serves major traffic movements while providing access to abutting land.

A speed-change lane, including tapered areas, for the purpose of enabling a vehicle entering the roadway to increase its speed to a rate of which it can more safely merge into traffic.

The average 24-hour volume at a given location over a defined time period less than one year.

The average 24 hour volume at a given location over a full 365 day year.

The average 24-hour volume occurring on weekdays over a 365 day year.

Concrete walls used in the median or between two adjacent roadways in order to prevent vehicles from crossing into oncoming traffic and to redirect errant vehicles.

A portion of a roadway that has been designated by striping, signing and pavement markings for preferential or exclusive use of bicycles.