The Dallas Area Rapid Transit (DART) Rail System boasts the longest light rail network in the U.S. The system operates 72 miles of track and services an annual ridership of over 22 million. DART and the Fort Worth Transportation Authority (the T) also jointly operate 35 miles of commuter rail. The Trinity Railway Express (TRE) serves as the link between downtown Dallas and Fort Worth and offers service to DFW International Airport. Through 2014, the DART Rail System is slated to grow to 90 miles.

DART’s light rail system is powered by overhead electric lines. Each rail vehicle is a state-of-the-art example of modern rail technology. A “catenary system” of two electrical cables provides stable working voltage for all trains on the 72-mile, 55-station system.

DART is unusual in that it has one of the few variable voltage power distribution systems in North America. Each substation is polled for energy usage and voltages are varied according to energy used and energy needed. Not all substations have to be operational for the light rail system to work. In the event of loss of utility power to a substation, the system is designed to provide enough power to compensate.

Along with multiple awards in design and engineering, DART is a pioneering leader within the public transit industry. In 2010, the agency received two awards for their innovative approach to light rail in Dallas. The Texas Section of the American Society of Civil Engineers recognized DART’s Green Line with its Texas Outstanding Civil Engineering Achievement Award. That same year, the Greater Dallas Planning Council awarded DART the 2010 BUILT Award for Urban Design. More recently, DART received the Design-Build Institute of America’s 2011 Transportation Owner of the Year – Rail Award for its successful use of the design-build approach in its capital expansion.

Operational challenges
Operating the largest light rail network in the U.S. is no small feat. Based on the agency’s five-year strategic plan to focus on meeting customer’s needs, strive for continual improvement and deliver quality service, DART pursued an ITS solution that would help them better manage their fleet and service their passengers. A primary goal was to track trains throughout the city with greater accuracy than the existing Supervisory Control and Data Acquisition (SCADA) system allowed.

The SCADA system left a few dark areas within its tracking so the dispatchers could not discern the exact location of a train within a block. In addition, DART’s route information contained limited time points on an operator’s hand-held schedule, which made it difficult for train arrival prediction at the stops. Because of this, DART could not automatically notify passengers of a train’s estimated arrival time, or of delays.

Also, capture of train operational statistics, such as precise arrival and departure times and passenger loads was a manual process, and other statistics like dwell time and door opening events were captured only by limited sampling.

In addition to the difficulty with tracking and predicting train arrival and departure times, passengers onboard or at the stops relied solely on train operators to make announcements. Messages were not always articulated clearly or understood by passengers, and making the announcements added to operator workload. DART needed a way to give passengers stop information consistently and with clarity — an important part of their approach to ensuring the safety and security of their passengers and employees.

Fleet management
In 2009, DART partnered with INIT, Innovations in Transportation Inc., a global ITS solutions provider, to provide a vehicle business system (VBS) for their light rail network. The system would address the challenges faced by DART and assist them in achieving their strategic goals. A comprehensive fleet management system was purchased along with automatic vehicle location (AVL) technology, automatic passenger counting technology (APC) and on-board signs and announcements. By partnering with INIT, DART realized several advantages, not just on the operations side, but on the passenger side as well. The new system afforded them the tools to efficiently manage their light rail fleet and better serve their riders.

For DART dispatchers, being able to track vehicles — above ground with GPS and through the tunnels via logical positioning — was a step toward safety and operational efficiency. This was accomplished through the on-board mobile data terminal where operators logged on to a block and trip allowing them to communicate with the central ITS system. This communication — every 20 seconds via GPRS — gave DART dispatchers location information displayed right at their workstations inside the control center. The real-time ETA could now be sent to the station signs for next train arrival information for the waiting passengers.

For train operators, the mobile data terminals gave them the ability to log on using a built-in card reader. From there, all timing information was displayed for each stop on the route giving the operator the correct information to help him or her know when to leave the station. For safety reasons, DART specified that the displays go dark while the vehicle is in motion to avoid operator distraction. As soon as the train stops at the station, the driver displays light up with all the necessary information.
On the passenger side, the advantages of the automatic on-board and at-station announcements were loud and clear. DART generated the announcement files at the central site and uploaded them via WLAN to the trains and stops where passengers could be kept up to date in real-time.

Extending technology
In 2012, DART decided to extend the system to the Trinity Railway Express, their commuter rail line. An AVL system, along with APC technology and on-board, next-stop announcements will be installed on the TRE. Additionally, 19 digital message boards located at ten TRE stations will be installed giving passengers the same level of service they enjoy on DART rail.

The new technology will seamlessly interface with the existing system at DART Rail and will utilize double-sided, ADA compliant LED signage, which will be installed at five stations in Dallas County and five stations in Tarrant County. The signage, along with the audible next train arrival announcements, will increase passenger satisfaction by providing DART and TRE customers with up-to-the-minute information for their travels.
As the agency continues to expand their light rail system over the next few years, the innovation and quality of service will only improve.