Engineering and Construction

Systems Technology


Some Intelligent Transportation Systems (ITS) equipment used by ADOT.

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511 Static Sign by road
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.
Vehicel with alert sign on back in parking lot
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 by road
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 cameras on poles
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 by road
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 over freeeway
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.
Vehicles that respond to and assist with a variety of road incidents
Emergency Response Unit
Located throughout Arizona, these vehicles are used to assist in a variety of road incidents.
Freeway assistance vehicles assisting motorists
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 fox by highway and advisory sign
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.
Roadway where loop detectors are installed.
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
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 on light pole
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 box along roadway
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 on freeway on-ramp
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.
RWIS Installation by roadway
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.
Thermal-Camera-Image Thermal Cameras
Cameras used to detect wrong-way vehicles at off-ramps.
Traffic Operations Center
Traffic Operations Center (TOC) Control Room
The TOC Control Room monitors statewide activities on all freeways and informs motorists of incidents.
Automated equipment on Truck Escape Ramp
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 staff.
Video switch for cctv cameras
Video Switch
A 256-port video switch permits view and control of over 100 CCTV cameras in the Phoenix metro area.

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