NEMA’s electroindustry July 2010 - 7

INTEllIgENT TRANSPORTATION

DMS Innovations Meet Agency Needs
toM BeCker, transportation sales Manager, daktroniCs, usa

An increasing number of U.S. agencies are examining the merits of dedicated DMS and full-color technology for dynamic message signs. Recent installations show an effective application of the technology.
A boom in proven intelligent transportation systems (ITS) and products, a push to find economical solutions, and a goal to reduce carbon emissions and traffic congestion have influenced U.S. transportation agencies to install an increasing number of dynamic message signs (DMS). Many agencies today use a combination of best practices and innovative solutions to inform motorists via DMS. full Color The realization of legibility dramatically increased the adoption of full-color DMS in the U.S. According to a recent University of Rhode Island study, enhancing textbased messages with images improves reaction time by an average of 35 percent. Adding color enables the creation of symbols and official icons found in the Manual on Uniform Traffic Control Devices. The California Department of Transportation (Caltrans) uses a Daktronics full-color DMS on SR 99 in Central Valley as part of a comprehensive, integrated system that also includes traffic sensors, visibility sensors, and closed circuit television cameras. It needed bright displays to shine through the local Tule fog, which can form quickly and without warning. The highly-visible displays use attention-grabbing imagery to advise

Photo courtesy of Daktronics, USA

motorists to slow down, thus preventing multiple-car incidents. The effective nature of full-color graphics allows traffic agencies like Caltrans to make conditions safer for motorists. The federal government has recognized the effectiveness of full-color DMS applications. Thus, the upcoming industry standard, NTCIP 1203 v02 Object Definitions for Dynamic Message Signs, will add specifications for graphics and full-color displays, minimizing implementation ambiguities. large toll networks Last year, the Ohio Turnpike Commission installed 230 DMS at 31 toll plazas across the state. Ohio is one of 14 states that use E-ZPass, the largest continuous, interagency toll system in the country. The commission placed the high-resolution, full-color displays above each lane to display the E-ZPass logo. The displays are operated remotely with LCD control pads. VariaBle speed liMits and hot lanes The challenge of variable speed limit signs (VSLS) involved developing a product that looks very similar to a static speed limit sign. VSLS, which are legible from a distance of more than 1,000 feet, use a high-resolution

LED technology with black text on a white LED background to mimic static speed limit signs. When drivers brake suddenly in congestion, the following wave of braking drivers is called a “shockwave.” The effect, seen in numerous worldwide studies, not only increases congestion but also smog, fuel consumption, and accident rates. By adjusting VSLS, the Florida DOT can alleviate the occurrence of the shock wave effect. Florida Department of Transportation (FDOT) installed 20 VSLS on a 10-mile stretch of Interstate 4 as part of its iFlorida project. Sensors detect speeds and overall

Photo courtesy of Daktronics, USA NEMA electroindustry

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July 2010

NEMA’s electroindustry July 2010

Table of Contents for the Digital Edition of NEMA’s electroindustry July 2010