The Denver Regional Transportation District (RTD) implemented an Automatic Vehicle Location (AVL) system and Computer Aided Dispatch (CAD) system to upgrade communications, improve safety, and monitor bus schedule adherence in real-time. RTD equipped its entire fleet of 1,335 vehicles (buses, light rail cars, and supervisor and maintenance vehicles) with AVL/CAD. The communications portion of the AVL system supports voice and data communications between dispatchers, drivers, and supervisors over nine microwave channels. Five channels are dynamically assigned to dispatcher-driver pairs, two channels are for data communications, and two channels are dedicated to maintenance and supervisor communications.

The GPS/In-Vehicle Logic Unit (IVLU)/Transit Control Head (TCH) on-board device is used for data communications. Drivers press a button on the TCH to initiate voice communication with the dispatcher. Supervisors are able to talk with the dispatcher and drivers via the in-vehicle equipment. Supervisors can contact a driver directly, or request the dispatcher initiate contact with the driver.

The costs of the three major components of the AVL/CAD system supporting driver communications, dispatch center hardware, in-vehicle communications equipment, and field communication hardware, are detailed below. Extended costs are the unit costs multiplied by the quantity of units.

Dispatch Center Hardware

The total cost of the dispatch center hardware was $1,247,866 (see table below). Costs included dispatch center hardware at all three centers for the Denver AVL system including the base radio communications hardware, radio/data computers, and the AVL consoles used by dispatchers to track the field vehicles. Installation costs are listed separately for each element, as applicable. The radio/data computer cost was $434,129.

 

In-Vehicle Hardware

The total in-vehicle hardware and installation cost was $5,231,814 (see table below). The total cost included equipment on the inside and outside of the vehicle enabling it to send and receive data and voice communications such as GPS/In-Vehicle Logical Unit (IVLU)/Transit Control Head (TCH), radios, and antennas. This cost also included AVL equipment used by field supervisors and maintenance, such as mobile data terminals. Installation costs are listed separately for each element, as applicable. The per vehicle cost for the mobile radio unit and GPS/IVLU/TCH unit are $1,545 and $3,517, respectively.

Field Communication Hardware

The total field communication hardware cost was $1,451,940 (see table below). The cost included all devices other than vehicle or dispatch center equipment required to establish communications to include microwave radio transmitters and antennas. Installation costs are listed separately for each element, as applicable.

The annual cost of maintaining all AVL equipment not in the vehicle for 1997 was $174,223. Examples of included costs are AVL manager salary, central processor maintenance, wireline communications and microwave towers maintenance, AVL manager station maintenance, software maintenance, and hardware (i.e., hard drives, printers) maintenance. Software and hardware maintenance were contracted on-call agreements for one year. A breakout of communications maintenance cost was not provided in the report. The report indicated that the maintenance costs for in-vehicle communications equipment (radios, IVLUs, and TCHs) were not specifically tracked; however, the cost is estimated to be the full time equivalent of approximately one person.

The operations cost for the AVL system was $1,723,404 and included the communication system including microwave towers, power used by the AVL system and communication towers, office supplies (i.e., paper, floppy disks), and salary and benefits for 25 to 30 full- and part-time dispatchers. A breakout of the communication system operations cost was not provided in the report.

For a breakout of all AVL/CAD system components and associated costs see the system cost summary - The Denver Regional Transportation District deployed a regional transit AVL/CAD system for $10.4 million; O&M costs were estimated at $1.9 million.