Knowledge Resources

The Utah CommuterLink Advanced Transportation Management System (ATMS) was developed so that operators in the Utah DOT Traffic Operations Center (TOC) could monitor and manage freeway and arterial traffic flow in the Salt Lake Valley. The ATMS consists of numerous components: a signal system, incident management team (IMT), variable message signs (VMS), ramp metering stations, highway advisory radio (HAR) system, closed-circuit television (CCTV) cameras, traffic monitoring stations (TMS), and road weather information systems (RWIS). The TOC is connected to a Salt Lake City and Salt Lake County traffic control center. The field devices and centers are connected via a fiber optic network which was installed as part of the ATMS deployment.

In 2003, an evaluation of the Utah CommuterLink Advanced Transportation Management System (ATMS) was conducted to assess the benefits and costs of the system. The capital cost of the ATMS was approximately $106 million. Annual maintenance cost was $377,800 and annual operational cost was $2.3 million. Based on the capital cost and estimated life of the system, the annual capital cost was estimated at $8 million. Including annual maintenance and operational costs, a total of $10.7 million is the estimated amount for the relative annual costs. Annual benefits of the system were estimated at $179 million yielding a benefit-to-cost ratio of 16.7.

ATMS component costs excerpted from the report are provided in the table below.

Component	Cycle Life (Years)	Total Capital Cost	Annual Maintenance Cost	Annual Operational Cost
IMT	6	$600,000		$400,000
Signals	7	$2,205,000	$15,000
VMS	20	$15,250,000		$21,960
CCTV	10	$8,400,000		$75,600
Ramp Metering	20	$5,750,000	$13,800	$8,280
TMS	10	$2,100,000	$42,000	$37,800
HAR	10	$250,000	$7,000	$3,600
RWIS	25	$1,250,000		$18,000
Fiber Optic Conduit/Cable	20	$51,176,000	$50,000	$150,000
Electronic Equip	5	$5,000,000		$150,000
Software	10	$5,000,000	$250,000	$750,000
Design Costs	1	$1,000,000
Additional Personnel Costs				$400,000
State TOC	20	$7,800,000		$100,000
City TOC	20	$100,000		$100,000
County TOC	20	$100,000		$100,000
Total System Costs		$105,981,000	$377,800	$2,315,240

Over 600 of the 900 signals in the Salt Lake Valley are connected to the traffic operations center (TOC). With the installation of the communication system and central traffic control system, monitoring and adjusting the signal system for special events is performed at the TOC. In addition, UDOT has implemented over 50 coordinated corridors in the Salt Lake Valley. The cost of the signal system includes only the communication capability. The signals were already in place prior to the ATMS implementation.

The Utah ATMS includes over 230 cameras to observe incidents and congested areas. Camera coverage is primarily on freeways and grade-separated facilities; however, there are some deployments at key intersections on surface streets. The capital cost of the cameras includes the cameras and installation.

Utah DOT operates and maintains over 69 permanently mounted variable message signs (VMS) on freeways and surface streets as part of the ATMS. Portable message signs are also used along roadsides where there is no permanent VMS. The annual operating cost is based on power consumption.

The Utah DOT employs traffic monitoring stations (TMS) at approximately ½ mile intervals along Salt Lake Valley freeways. The in-pavement congestion sensors allow CommuterLink operators to monitor traffic conditions. The sensors provide operators with information on traffic volume, speed, and congestion. Annual operational cost is based on power consumption.

The Utah DOT employs 24 freeway ramp meters as part of the ATMS. Ramp metering consists of sensors and traffic signals at freeway entrances to control the number and frequency of vehicles entering the freeway. The capital cost of ramp metering is the full cost to implement, including the design, equipment, and installation.

Notes:
See Also:
Utah Department of Transportation CommuterLink Website - http://commuterlink.utah.gov