| Word |
Description |
| AADT |
Annual Average Daily Traffic |
| AADTT |
Annual Average Daily Truck Traffic |
| AASHTO |
American Association of State Highway & Transportation Officials |
| Actuated Controller |
A traffic signal controller that receives information from vehicle and/or pedestrian detectors and provides signal timing accordingly.
|
| Actuation |
The operation of any type of detector (NEMA). The word operation means an output from the detector system to the controller unit. |
| ADT |
Average Daily Traffic |
| ADUS |
Archived Data User Service |
| Advisory Detector |
The detection of vehicles on one or more intersection approaches solely for the purpose of modifying the phase sequence and/or length for other approaches to the intersection (NEMA). |
| Alternating Current (AC) |
A current which reverses direction at regular intervals. the rate of reversal is expressed in hertz (cycles per second). |
| Ampere |
The unit expressing the rate of flow of an electrical current. One ampere is the current flowing through one ohm resistance with on volt pressure. |
| Amplifier |
See Detector Amplifier. |
| Analog |
An electronic design that uses continuously varying voltages, rather than digital numbers. |
| ANSI |
American National Standards Institute. |
| Antenna |
The radiating of receiving elements utilized in transmitting of receiving electromagnetic waves (NEMA). |
| Apollo |
For information on our Apollo Classifier Click Here. |
| Area Detection |
The continuous detection of vehicles over a length of roadway wherein the call of a vehicle in the detection area is intended to be held for as long as the vehicle remains in the area of detection. (Most detectors cannot hold the call indefinitely).
Frequently referred to as large-are detectors, long-loop detectors, or presence detectors. |
| Area Detector |
See Large Area Detector. |
| Area of Detection |
See Zone of Detection. |
| Arterial |
A major urban roadway usually with coordinated signals along its length. |
| ARTS |
Advanced Rural Transportation Systems |
| AS475 |
AS475 Grout |
| ASTM |
The American Society for Testing and Materials. |
| ATIS |
Advanced Traveler Information System |
| ATMS |
Advanced Traffic Management System |
| ATR |
Automatic Traffic Recorder |
| Auxillary Equipment |
Separate devices used to add supplementary features to a controller assembly (NEMA). |
| AVC |
Automatic Vehicle Classification |
| AWG |
American Wire Gauge. The standard measurement of wire size. It is based on the circular mil system. 1Mil equals .001 |
