• The Traffic or Transportation Management Center (TMC) is the hub of a transportation management system, where information about the transportation network is collected and combined with other operational and control data to manage the transportation network and to produce traveler information. 
• It is the focal point for communicating transportation-related information to the media and the motoring public, a place where agencies can coordinate their responses to transportation situations and conditions.
• The TMC links various elements of Intelligent Transportation Systems such as  variable message signs, closed circuit video equipment, roadside count stations, etc., enabling decision makers to identify and react to an incident in a timely manner based on  real-time data.

Key Results

TMCs can help reduce incident response times, lower incident rates (mainly secondary incidents), disseminate traveler information and hence reduce congestion and enhance safety. To date there is little data quantifying the exact benefits resulting from TMCs. One study conducted by MnDOT reported decrease in accident rates by 25 percent, 20-minute reduction in response time, 35% increase in average speeds (34 mph to 46 mph) during rush hours and 22% increase in capacity of freeways, after the implementation of their TMC.

Benefits

TMCs provide a number of potential benefits. The main benefits are:

• Faster incident response and reduction in incident rates.
• By broadcasting traveler information and coordinating their activities with the State Patrol, etc, TMCs have been successful in reducing congestion in freeways and arterials. 
• Increases traffic safety by effective incident response and clearance techniques. By providing traveler information regarding incidents it minimizes the likelihood of secondary incidents.
• Enhanced communication in all aspects of transportation management (planning, design, implementation, operation, maintenance). 
• Monetary savings by sharing responsibilities between fewer staff, achieved by co-location of participating agencies at the center. 
• Agencies working closely together in a TMC typically produce a more consistent, unified response to a situation, increasing the overall effectiveness of the transportation resources. 

Costs

The cost of implementing TMCs vary depending upon the size and functions of the TMC. Overall costs involve:

• Conception, design and implementation of TMCs.
• Yearly operational costs including the cost for co-hosting the number of agencies present. (For example, the yearly operation budget for Seattle TMC is in the range of  $1.4 million, and that for San Antonio  ranges from $700,000 to $1 million.               The Houston TranStar is located in a $11.5 million, 52,000 sq. ft. TMC housing transportation and emergency personnel.)

Implementation and Operational Challenges

The challenges that a modern transportation management center face are not confined to implementation alone, equally challenging is its operation and maintenance. 

• The TMC planning, design, and implementation involve not only several departments within the implementing agency (or agencies), but also the efforts of a variety of private sector product and service providers. This requires both significant coordination and ongoing effort to build and maintain consensus. 
• The TMC may be in planning, design, and implementation several years, requiring it to deal with multiple technology generations.
• The agency owning the TMC faces a daunting challenge of implementing, operating, and maintaining not only a complex transportation environment, but a mass of complex and rapidly evolving technology. 
• Often, multiple individuals and organizations are involved in any given transportation situation, with differing (and potentially unclear) roles and responsibilities. These participants may be acting from incomplete understandings of the situation and with differing motivations and priorities. Communication and coordination between the participants is seldom complete. 

Where is it implemented?

Throughout the United States, Western Europe and South East Asia and on a more limited basis in Latin America.

Author: Indu Sreedevi