Intelligent Transportation Systems in Work Zones: A Case Study - Work Zone Traffic and Incident Management System - Keeping Traffic Moving During Reconstruction of the Big I, a Major Interstate-Interstate Interchange in Albuquerque
The New Mexico State Highway and Transportation Department (NMSHTD) rebuilt the Big I interchange in Albuquerque to make it safer and more efficient and provide better access. The original Big I was severely over-capacity. NMSHTD employed an ITS-based mobile traffic monitoring/management system to help move vehicles through the extensive construction area. ITS components were deployed prior to construction with plans to later incorporate portions of the system into a permanent freeway management system.
NMSHTD used ITS for several reasons:
- Changes in traffic patterns, closures and alternate routes required that travelers be provided with high-quality real-time information.
- The high volume of traffic moving through the interchange created great potential for congestion.
Three main project goals included:
- Provide traffic management capabilities and traveler information on traffic routing, detours, and incidents.
- Minimize capacity restrictions due to incidents.
- Enhance traveler safety.
The project included cameras and sensors to monitor traffic conditions and detect incidents, electronic signs, highway advisory radio, a website, and other media to transmit traveler information. Incident detection was a major component. Lessons learned related to the importance of a reliable communication system, scheduling and planning, public awareness, interagency coordination, and consideration of future maintenance requirements.
When undertaking large-scale construction projects it is necessary for agencies to use various ITS to implement a reliable communications system. The use of ITS in work zones can help alleviate concerns associated with safety, mobility and costs. By developing an effective communications system, agencies are better able to make work zone conditions run as smooth as possible, for all roadway users. There are a number of ways to apply ITS to develop reliable communication systems in work zones, including:
- Deliver accurate information to the public for successful management of work zones. The New Mexico State Highway and Transportation Department (NMSHTD) employed an ITS-based mobile traffic monitoring and management system to help move vehicles through an extensive construction area. NMSHTD used ITS in part because frequent changes in traffic patterns and scheduled closures required that travelers be provided with high-quality real-time information. Among the ITS used to distribute this information were DMS, a website, and automated fax and email updates.
- Maintain the ability to rapidly respond to dynamic roadway conditions. This is especially useful when police, fire or emergency personnel are needed to assess incident severity in order to send the correct number of vehicles; this will result in reduced costs and will free up units to respond to other incidents.
- During the Big I interchange ITS deployment NMSHTD employed staff at the traffic management center (TMC) from 5:00 am to 8:00 pm Monday through Friday, in order to detect any incidents. The staff were able to:
- Notify emergency personnel for dispatch.
- Post messages on electronic roadway signs.
- Provide traveler information to the public via the Internet and a pager network.
- Provide the means for staff to easily make changes to communication sources, should it be required. This will save TMC staff considerable effort in informing travelers of changes in the work zone and detours.
- The mobile traffic monitoring and management system software for the Big I interchange ITS deployment held a set of message scenarios for the electronic roadway signs. Because the core of the Big I interchange was entirely closed to traffic most nights to facilitate roadwork, a whole series of detour messages were required each night. The system enabled TMC operators to activate a pre-defined message scenario for all the DMSs with "one click." These scenarios were not set to activate automatically, although that option did exist.
- During incidents, NMSHTD could manually activate DMS messages indicating the accident location, lanes affected and whether delays were occurring.
ITS technologies can greatly enhance communications within work zone settings, improving mobility and safety while simultaneously cutting costs. Through use of the mobile traffic monitoring and management system NMSHTD reduced work zone crashes by 32% in the first three months, compared to the previous year. With the new ITS system, incident response and clearance time was reduced from 45 minutes (historically) to 25 minutes in the work zone, and a 15% reduction in traffic was experienced from travel demand management techniques. Lastly, the new ITS system allowed NMSHTD to substantially reduce costs and improve public relations.