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Public Roads - Summer 1995

TransGuide Leads the Way in Innovative Transportation Management

by Vincent P. Pearce
The integrated transportation management system supports real-time monitoring and control of traffic.



San Antonio is the nation's ninth largest city. It has a booming tourist trade -- centered around the Alamo, River Walk, Fiesta Texas, and Sea World -- and six military bases and a steadily growing economy.

As the city has grown, it has experienced increasing traffic problems. Traffic volume on some freeways in the city now exceeds 205,000 vehicles per day. Several years ago, San Antonio transportation authorities began discussing how the region could avoid -- or at least minimize -- urban gridlock. In 1994, traffic was further exacerbated by the opening of a 65,000-seat domed stadium with only 2,800 parking spaces in the city's downtown area. Each day, San Antonio suffers an average of 100 traffic accidents -- about 12 percent of which are secondary freeway accidents. These accidents -- combined with maintenance, construction, and increasing demand -- are slowing the city's freeway system.

Under the leadership of the Texas Department of Transportation (TxDOT), a plan was formulated to deal with this problem. The result was TransGuide, subtitled "Technology in Motion," a project emphasizing intermodal/interagency cooperation and innovation in technology and procurement. TransGuide's goal is to provide information on transportation conditions and options to the traveling public in and around metropolitan San Antonio.


Both large and small video displays support operations.
Personnel from TxDOT, law enforcement, and transit work in the control room.


Rejecting Traditional Solutions

The traditional, but very expensive, solution to the congestion problem is to build additional lanes and/or roads. TxDOT, however, was interested in making its existing road network work smarter and better, rather than just adding new lanes. Planners decided to develop and implement an Intelligent Transportation System (ITS) that would drastically reduce the time needed to detect and respond to an incident.

The TxDOT system -- TransGuide -- will reduce detection/response time from 20 minutes to 2 minutes. It will also enable traffic controllers to dispatch all necessary emergency services before an officer even reaches the accident scene. According to a TxDOT report, this rapid response and the corresponding reduction in the impact of incidents on traffic conditions should result in a 22-percent increase in average freeway speed, a 43-percent reduction in number of traveler stops on the freeway, and a 27-percent reduction of overall freeway system delay. Quantified, this comes to an annual delay savings of $513 million, generating a benefit-to-cost ratio of 30-to-1 when the project, covering 307 kilometers (km) of freeway, is fully operational.

Traffic flow is aided by an excellent system of three-lane, parallel arterial roads along the freeway network. These "frontage roads" provide ideal diversion routes around freeway incidents without affecting other city streets.

Since vehicles will be moving at more efficient speeds, TransGuide will also lead to improvements in the environment. Improved fuel efficiency should result in annual reductions of 128 metric tons (t) of carbon monoxide, 13.5 t of hydrocarbons, 17.2 t of nitrogen oxides, 1 t of sulfur oxides, and 112 t of ozone precursors. Annual fuel consumption is projected to be reduced by almost 12 million liters.

Procurement Innovation "Paves" the Way

To make TransGuide a reality, its planners relied on two distinct types of innovation: state-of-the-art technologies and state-of-the-practice procurement and teaming techniques. Thus, the way in which TransGuide has been developed is just as new and exciting as the tools that comprise it.

The first step for TxDOT was to build a consensus among local agencies and authorities in an existing corridor management coalition, which included representatives of local law enforcement and emergency services, the city and county, and the metropolitan public transit service. It was important to achieve a consensus since TransGuide changes the way in which agencies work -- and work together -- to identify and manage incidents and to manage and improve overall traffic conditions. The results are a more tightly coordinated incident response program and extensive sharing of information from TransGuide and other sources to enhance both incident response time and level of preparedness.

TxDOT officials reviewed traffic management systems and control room environments around the country. During their visits, they aimed to identify both appropriate technologies for the system and companies that were able to design, equip, and support complex modern systems and control centers. TxDOT staff began to develop preliminary design concepts based on what they had seen.

Next, with the caveat that TxDOT would not accept a proprietary or sole-source solution, industry was invited to make recommendations on these concepts. Companies involved in the design-development effort included DEC, AlliedSignal Technical Services Corporation, AT&T, Ikegami, Canon, and Fiberoptic Display Systems. The resulting design was a mix of existing state specifications, "special" specifications, and "functional" specifications for the control center and computer system.

Industry was then invited to bid on the project, which was to be funded through federal-aid highway construction funds (80 percent from the federal government and 20 percent from the state government) with additional system extensions paid for by VIA Metropolitan Transit, the San Antonio transit (bus) company. (VIA is not an acronym; it means "by way of/by means of.") In addition, the San Antonio District of TxDOT dedicated one-third of its total construction budget to this project in the year it was awarded. The fixed-price procurement was awarded in December 1992 to the lowest bidder, AlliedSignal Technical Services Corporation, which headed up a team of more than five dozen subcontractors and suppliers.

Both variable message signs and lane-control signals support the traffic management system by providing appropriate information to motorists.

The integrated transportation management system supports real-time monitoring and control of traffic.

Process Innovation

The innovative management practices exhibited during the project design and development stages continued well beyond actual project startup. Specifically, every step of the project emphasized "partnering." In partnering, the contractor team and the contracting agency lay out ground rules under which they will work. So, with the aid of a partnering facilitator, the TransGuide project team developed mission and vision statements, a goal, and a detailed process for issue resolution. Lower tier subcontractors on the project commented that they "felt, for the first time, that [they] were an important part of a team working toward an important goal."

Partnering has yielded measurable results. First, the project has proceeded to the 99-percent-plus completion level with no claims. While completing a traditional multimillion-dollar, low-bid, fixed-price, construction project without any claims is somewhat unusual, completing a claimless project that mixes construction and multiple advanced technologies in the same contracting process is even more noteworthy. Second, the project has been accomplished in a significantly shorter period of time than have comparable advanced traffic management system (ATMS) projects around the country. Third, TxDOT identified the project as being responsible for its largest cost savings in 1993 (ranking over projects nearly three times as large), with savings to the state (at the 90-percent completion level) calculated at $1.9 million.

Innovative System Design

So what is the TransGuide project? Basically, the 39.4-km project features pairs of inductive-loop-type vehicle detectors in each lane at 0.8-km intervals, video cameras every 1.6 km, and a fiber-optic communications network. Transportation operations personnel use a window-driven, client-server computer system with a real-time, digital map display to develop and implement specialized response scenarios for each traffic incident. Inside the 4459-square-meter control center, video and computer images are displayed on console monitors and on a 3-meter by 18-meter video wall. Fiber-optic variable message signs and overhead lane control signals posted along the freeway and on ramps inform motorists about traffic conditions. Freeway management is integrated with management of arterials and city streets through computer control of traffic signals.

The system design includes multiple technical innovations. The digital communications system multiplexes voice, data, and compressed digital video over individual fibers at 155 megabits per second. TransGuide is one of the first systems in the United States to use the Synchronous Optical Network (SONET) standard to ensure interoperability of equipment from multiple vendors. The central computer is "fault-tolerant," ensuring 99.999-percent availability. Video coverage is full-motion and full-color at up to 48-to-1 magnification, which is expected to result in superior information to emergency services as they are dispatched to the incident scene. At the front of the control room, a commercial-quality "video wall" display (with only a 9.5-mm dividing line between cubes) can display up to 80 video and computer-generated images.

How It Works

The operating concept of the system begins with monitoring speed and occupancy on the freeway to detect incidents. After a suspected incident is identified through a series of algorithms, the computer notifies a traffic operations incident "manager," who rapidly determines (through the video system) if the incident is real. If it is, the incident is assigned to an operator, who investigates and provides additional information to the computer. The system then recommends a unique solution to resolve the incident, which the operator can accept, modify, or reject. Once a scenario is implemented, the system continues to report changes in traffic conditions, allowing the operator to develop and implement an alternative scenario if necessary. Safeguards are built in to ensure that conflicting scenarios are not implemented.

The new traffic management center was designed and constructed to put all the key players under one roof. In addition to the TransGuide managers, operators, and maintenance people, representatives of several other organizations are colocated in the center. Representatives of VIA, police, emergency services, and environmental response units will work in the control room and will dispatch units in response to incidents. The operations control center's third floor will house VIA's fixed route and paratransit dispatch, emergency management, and an adjunct of city traffic engineering signal control. Joining the working project partners on the top floor will be the Texas Transportation Institute, performing research on improved incident detection algorithms and other transportation programs that can benefit from access to real-time data and video. The building is wired for voice, data, and video throughout, including a "situation room" adjacent to the control room.


Operations personnel use a specifically designed client-server architecture computer system.


Project Status and Future

The TransGuide development effort was a two-year project. Full operation following system acceptance testing is expected in mid-1995. Many activities had to be performed simultaneously in order to finish the project within this time frame. For example, while work crews installed conduit and cable and constructed the control center in San Antonio, AlliedSignal software personnel designed and developed the computer system and created a working ITS test bed at their facility in Columbia, Md. The result was that when the software was delivered to San Antonio, it had already been proven in operation with identical equipment, considerably shortening the integration period.

Last year, TxDOT's public relations department began planning for system startup, retaining a public relations firm to support a full-scale public information program. Project coverage has been extensive in both print and broadcast media. Print and video materials have been developed to inform the public about TransGuide and to maximize traveler comprehension of and compliance with the traveler information and advisories provided.

Operations and maintenance personnel have been fully trained in an intensive effort, and system documentation has been delivered by the contractor. Also, system modifications that extend the communications network to VIA's two downtown control rooms, park-and-ride lots, an underground bus garage, and the TxDOT district traffic engineering office are under way.

The TransGuide Operations Control Center has become a popular site visit for federal, state, and local transportation officials interested in seeing the state of the art in action. Last year, for instance, the facility hosted a meeting of ITS America's ATMS Committee. In mid-1995, it will host the Transportation Research Board's Freeway Operations Committee.

This year, additional contracts will be let to extend the area covered by the system. A project has been initiated to integrate traffic and transit information and to make this pretrip information easily available at convenient locations for the traveling public. Additional functions have been identified for the TransGuide system, and steps toward further automation of operators' tasks are planned.

Given San Antonio's strategic location, TransGuide is likely to serve eventually as a transportation management hub for south and southwestern Texas, incorporating other ITS functions from commercial vehicle operations, advanced rural transportation systems, and advanced traveler information systems. The core system is online, but there are many exciting capabilities that have yet to be incorporated.

Vincent P. Pearce is the senior manager for transportation systems and services of AlliedSignal Technical Services Corp. He was extensively involved in the development of the TransGuide computer and communications system specifications and has continued to support TxDOT in the design of operational tests and other traffic management systems in the state. He chairs a subcommittee of ITS AMERICA's Standards and Protocol Committee, and he is one of four U.S. representatives to the ISO ITS Technical Committee's ATMS Working Group. He has a bachelor's degree in mechanical engineering from North Carolina State University and a master's in business administration from Harvard University.