| ||511 Static Sign |
These are signs along Arizona roadways that remind travelers they may call 511 and obtain up-to-date traveler information. Despite the rural location of these signs, callers should have cell coverage in areas where signs are posted, such as this one along I-8.
| ||Alert Vehicle |
Specially equipped vehicles respond to incidents throughout the Phoenix metro area, providing on-site command and control, portable DMS (see below) capability and more.
| ||Call Box |
These tools are placed along rural roadways, where cellular telephone coverage is unavailable, for stranded motorists to contact DPS. This particular box is located on US 93 at the Santa Maria River bridge.
| ||Closed Circuit Television (CCTV) |
Located high above roadway to provide view of traffic incidents, most CCTVs can pan, tilt and zoom (PTZ) from any workstation at the TOC. The CCTV shown, like most, is installed with a lightning protection rod.
| ||Controller Cabinet |
Controllers sit along the roadway and send information from such items as PADs, loops, ramp meters to the TOC. These cabinets are not air conditioned, so all equipment is "field hardened" to withstand Arizona summers.
| ||Dynamic Message Sign (DMS), Large |
These large signs are over or near roadways and are used to display messages to the public. Larger DMS (as shown) have three rows of 18 characters, with each character measuring 18" tall.
|Emergency Response Unit |
Located throughout Arizona, these vehicles are used to assist in a variety of road incidents.
|Freeway Service Patrol |
More than half a dozen vehicles assist motorists in the Phoenix metro area 18 hours a day, seven days a week. This service is operated by DPS.
| ||Highway Advisory Radio (HAR) |
HARs are used to give special announcements within a short distance of the transmitter and are often used in Arizona for rural road construction. Travelers will be advised to tune radio to a particular channel.
| ||Loops |
These devices are detectors embedded in the roadway to detect vehicle movement and permit workers to determine vehicle speed and density. This information feeds the speed maps (color maps depicting flow of traffic). See also PADs.
| ||Node Building |
These buildings collect regional information (e.g., from various controller cabinets) and send it to the TOC. These facilities have fault-tolerant air conditioning systems to maintain moderate summer temperatures.
| ||Passive Acoustic Device (PAD) |
PADs are small devices that sit near the top of utility poles — barely visible to drivers below — that can detect vehicle movement. These devices permit us to determine vehicle speed and density. This information feeds our speed maps (color maps depicting flow of traffic). See also loops.
|Pull Boxes |
That are various-sized boxes along the roadway in which lines (e.g., fiber, power) are pulled and spliced as they make their way to various components. The pull box shown here is a Number 9.
| ||Ramp Meter (RM) |
Designed to maximize balance of freeway traffic flow with oncoming traffic, ramp meters are used on most ramps where volumes are high.
| ||Road Weather Information System (RWIS) |
This collection of meteorological apparatuses provides information on nearby roadways. RWIS installations often have CCTV cameras pointing in both directions of the roadway.
| ||Traffic Operations Center (TOC) |
The hub of the Transportation Technology Group's operation, the TOC monitors statewide activities on all freeways and works, among other things, to inform motorists of incidents. A high-resolution version of this photo is available in Documents.
| ||Truck Escape Ramp (automated) |
Sensors detect a truck entering the ramp, turn on the "in use" sign and send notifications (with photos) to DPS and ADOT personnel.
| ||Video Switch |
A 256-port video switch permits view and control of over 125 CCTV cameras in the Phoenix metro area.