Engineering Inc. - July/August 2007 - 31

MULTI-PROJECT FEATURE Memphis Upgrades Highways THE SMaRTWay Gresham, Smith and Partners he roads in the city of Memphis—similar to the roads in most major urban areas—are growing more crowded each year with local traffic coupled with more interregional and interstate congestion. But building yet another highway lane can cost $3 million per mile—and that doesn’t take into account property purchases or the inconvenience that construction causes motorists. Enter TDOT SmartWay, the Tennessee Department of Transportation’s management system along the state’s urban interstates that aims to reduce congestion, delays and accidents through a series of communications and information technologies collectively known as an “Intelligent Transportation System,” or ITS. TDOT purchased its urban Memphis ITS project at the relatively bargain rate of about $400,000 per mile—less than one-sixth the total cost of Digital billboards (left) and overhead cameras (right) are two components of tennessee’s “Intelligent transportation system.” rodney Chester T adding a new highway lane. Among its many amenities, the system features closedcircuit television cameras used to more effectively monitor traffic and congestion; special roadway sensors to gauge speed and travel time; electronic signs that broadcast information and real-time traffic updates to motorists; a state-owned fiber optic network; and a Highway Advisory Radio System that enables travelers throughout the region to get up-to-date traffic information via a specified AM radio frequency. The system will be monitored and operated from a new 16,000square-foot, state-of-the-art transportation management center. “The goals of the project were focused on improving incident management and traveler information in the Memphis region,” said Rodney Chester, principal engineer for Gresham, Smith and Partners, the contract engineer for the project. “The project includes devices in both Tennessee and Arkansas and will eventually be connected to other devices installed in Mississippi in the future.” The TDOT SmartWay in Memphis is one of the largest single-contract ITS projects in the nation, covering about 83 miles on sections of I-40, I-240, I-55, SR-385, Sam Cooper Boulevard in Shelby County, Tenn., and Crittenden County, Ark. Officials say the new technology is designed to ensure that appropriate emergency personnel respond to an accident, while, at the same time informing motorists of potential trouble spots on the roadways ahead. By advising travelers in advance to stay alert and reduce their speed, state transportation officials estimate they can reduce instances of secondary accidents by more than 30 percent. State-of-the-art technology provides a wireless link between Memphis and state transportation headquarters in Jackson, Tenn., approximately 80 miles east of Memphis. The link is the first phase of a statewide wireless system that eventually will connect four cities—Memphis, Nashville, Knoxville and Chattanooga—over 634 miles of roadway. “Because multiple states are affected by this project, coordination between each state’s [department of transportation] was imperative,” Chester said. “Because the SmartWay system adjoins the Mississippi state line, but doesn’t cross it, designers made sure that [Mississippi Department of Transportation] officials were involved in the early planning stages. The officials could thus completely understand how the system would operate, in the event Mississippi chooses to connect to or extend the system in the future.” n JULy/AUGUsT 2007 ENGINEERING INC. 31
Engineering Inc. - July/August 2007

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