By: Tim Gregorski
To help meet the transportation needs in the state of Utah and specifically in the Salt Lake City area, state and local officials have implemented the CommuterLink advanced traffic management system (ATMS) to assist in the management of the region’s traffic flow.
With a goal of improving the efficiency of existing highways leading to the city as well as roads in the downtown area, the ATMS provides instrumentation on 70 miles of area freeways. The system includes closed circuit TV (CCTV) camera coverage every 1,000 meters, traffic monitoring systems that entail embedded loop detectors and microloops approximately every 800 meters, 31 variable message signs (VMS) located on the freeway, four weigh-in-motion stations on the I-15 corridor, seven roadway weather information stations (RWIS), and a fully redundant, self-healing fiber optic backbone communications system.
This combination of electronic traffic equipment, computers and communication systems incorporates technology to make traveling along the Wasatch Front, I-15 and within the city of Salt Lake safer and more efficient.
"The system also includes ATMS elements on surface streets including the interconnection of 550 traffic signals, surface street CCTV cameras and surface street VMS signs," said Peter Marshall, Utah Area Manager for PB Farradyne, the ATMS program management consultant for the I-15 project.
Additionally, the system provides the ability to dispatch quicker roadside assistance in the event of an accident or relay information, such as a message warning of impending weather situations, to the motorists, according to the Utah Department of Transportation (UDOT). It is important to note that UDOT maintains that the system will not solve all of the traffic problems or eliminate the need to build new roads in the Salt Lake City area, but it may help save lives, time, money and ease the frustration level of drivers.
Putting up big numbers
Commonly referred to as the largest single highway construction contract in U.S. history, the ATMS equipment within the area’s infrastructure costs about $70 million.
"It should be noted that only a small portion of this amount was within the reconstruction area of I-15 itself," said Mike Holling, vice president of TransCore, UDOT’s ATMS systems manager. "The I-15 project was the mechanism by which UDOT was able to install the ATMS system across the Salt Lake Valley."
Funded by a combination of state and federal funds, the total cost of the I-15 reconstruction plan is $1.318 billion.
Seven public agencies provided funding for the CommuterLink project. These agencies include: UDOT; Salt Lake City; Salt Lake County; the Federal Highway Administration; Utah Transit Authority; Wasatch Front Regional Council and; the Department of Public Safety.
Concurrent with the field construction, UDOT used separate contracts to construct a traffic operation center (TOC).
Built for a cost of $80 million of which nearly 25%was federal-aid funds, the TOC functions 18 hours a day, seven days a week with two operators on duty.
As the epicenter for the management and control of Salt Lake City’s ATMS field elements, the TOC houses all the computer and communication systems that provide instant data on road conditions.
"It serves as a link to two other transportation centers in the Salt Lake City region that are run by the city and the county, making it possible to link freeway management operations from the UDOT center with traffic signals on the surface streets via integration," said Holling.
Recognizing the importance of integration and interoperable systems, Utah invested in the development of a national ATMS architecture to connect the transportation centers and their systems together.
"Traffic signal synchronization is occurring through updating of time-of-day plans," said Holling. "We have not yet developed special event plans. Although a number of incident response plans are being developed that could be implemented in an automated fashion at some point in time."
In addition to traffic signal synchronization, the main role of the TOC and its network is to detect and determine the source of traffic problems on the roadways and provide the appropriate responses to reduce delays at accident scenes and restore traffic conditions to normal in as little time as possible. Personnel in the TOC control and monitor CommuterLink and can dispatch highway patrol, UDOT incident management and UDOT signal maintenance crews.
"The TOC’s primary function at this point in time is to facilitate response to incidents via video confirmation of incidents and to put messages on the VMS," said Holling.
Systems expansion
At this point in time, the majority of the ATMS infrastructure that is not within the construction zone of I-15 itself is online.
"More devices are brought online every week as the fiber optic cable is extended," said Holling. "All field elements outside of the I-15 area should be online by August 2000, while system elements being installed with the new freeway section will be completed by July 2001."
The primary achievement is the very rapid deployment of the ATMS. According to Holling, major setbacks were avoided by the use of the design-build process, an effective partnering program and co-location of the designer, contractor and owner.
"The project has gone remarkably smooth thus far, with no major problems or incidents," added PB Farradyne’s Marshall. "We have recently hit a major milestone of bringing nearly all of the traffic signals in the downtown area online to the new communication system. Almost all of the freeway ITS devices off the I-15 corridor are online and working."
In addition to the ATMS systems being installed in the city, the outskirts of Salt Lake incorporate ATMS applications involving RWIS stations, canyon VMS signs and a fog warning system.
"These applications are isolated and not related to I-15," said Marshall. "Eventually, UDOT plans to connect these elements to the TOC."
The system installed with the I-15 project comprises essentially the entire ATMS program within the entire city. There are separate initiatives under way in the transit domain as well as several geographic expansions to this core infrastructure.
Style all its own
There are features of the I-15 project that distinguish it from other ATMS projects across the country. First, all of the system’s elements identified earlier were installed under a single contract. This is by far the largest deployment of an ATMS that has ever been undertaken within one contract in the U.S. Second, the deployment utilized the design/build procurement method resulting in the design and construction being completed within the designated three-year timeframe.
"The most unique fact about the Salt Lake ATMS is that it is being installed all at once, with no legacy systems to incorporate," said Marshall.
Additonally, the Utah Transit Authority (UTA) is in the process of developing an ATMS Master Plan. The elements of this plan may include automated passenger counting, electronic fare collection and display of bus and rail locations on video screens, among others.
Meanwhile, geographic expansion is occurring in the I-80 area that would enable the ATMS to be extended to venues for the 2002 Winter Olympics in the Park City area. Infrastructure also is being planned for deployment in the E-Center area.
"UDOT has an aggressive ATMS expansion program in which ATMS elements are being added in with other major roadway projects in and around Olympic venue sites," said Marshall.
As for the immediate future, plans for CommuterLink include an extended area of coverage and a telephone hotline that gives callers updates on road conditions and detailed messages concerning specific incidents. UTA transit buses and light rail equipped with automatic vehicle locators also will provide real-time transit schedules.
