Traveler Information Program Area
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Operational Scenario
It's 6:30 PM on a summer Friday evening in the Washington, DC area. Between the commuter rush hour traffic and the typical weekend migration of travelers in and out of the city for recreation trips, traffic is heavy on most roads. Three of the millions of travelers impacted conditions this evening are Richard, coming in from Richmond on I-95 to attend a large concert on the Mall; Dan, who works in D.C. and takes Metro to a suburban park-and-ride lot from which he drives home; and Jennifer, who commutes between her job at the National Postal Museum in Washington and her home in western Alexandria, Virginia.
Information on traffic conditions is available to these three travelers from a wide variety of sources, many of which are operated by, or utilize information provided by, the VDOT NOVA Smart Traffic Center (STC) and their regional partners. Traveler information in the region is assembled from a number of sources including:
- Telephone calls from travelers reporting incidents and other conditions
- Observations of incidents and other conditions by the State Police and other law enforcement
- Observations from the VDOT Safety Service Patrol (SSP) vehicle operators who patrol roadways providing assistance to travelers and assisting with traffic incidents
- Observations from VDOT maintenance crews whose work throughout the system provides them a first-hand opportunity to observe conditions
- Telephone calls from the media reporting or inquiring about conditions
- Vehicle traffic detectors along roadways which monitor traffic flow and flag slow-downs that could be indicative of incidents
- Closed-circuit television (CCTV) surveillance cameras located along key freeways throughout the region and which are used by the STC and other traffic operators to monitor conditions and verify potential incidents
- Notices of planned maintenance and construction activities are provided to the STC from a wide variety of transportation and utility agencies and private contractors conducting activities that could impact roadways
- Notices of special events are provided by National Parks and commercial venues to the operators of the Virginia 511 state-wide traveler information system
- Commercial traffic reporting services operating their own information systems (e.g., websites) or who provide information to other information outlets (such as radio and television broadcasters) utilize their own roving vehicles, aerial surveillance, and other techniques to collect information.
Information is collected by various organizations and entered into various systems operated by individual organizations. Much of the information collected by individual organizations is shared with other organizations in the region via a variety of means. For example, information sharing between commercial traffic services and the NOVA STC may occur by telephone or fax. The information on incidents collected by the STC from a variety of sources is entered into its own traffic management system from which information passes to the DC area Regional Integrated Transportation Information System (RITIS), which provides access to the information to a wide range of transportation organizations and provides STC access to information entered by those other organizations. STC traffic surveillance video images are also made available to other organizations via the VDOT Video Clearinghouse.
Our weekend tourist, Richard, coming into D.C. for the concert, obtains information from a number of sources. En-route from Richmond on I-95, Richard utilizes the 511 Virginia telephone information system to learn about incident-related congestion around the I-95 interchange with State Route 3 and chooses to detour onto US 1 through Fredericksburg. As he enters Washington, DC on I-395, he sees VMS messages alerting him of congestion on US 1-his usual approach to the Mall. Richard decides to stay on I-395 awhile longer and back-track slightly to the Mall from the east, avoiding much of the heavy traffic.
Meanwhile, Metro park-and-ride commuter Dan is stepping off at the Vienna Metro station. Walking to his car, Dan consults his combination cell phone/personal digital assistant for any traffic advisories for I-66 westbound, his usual route home to Centreville. Dan subscribes to a personalized commercial traffic information service that sends Dan e-mail advisories when there are incidents anywhere along his pre-defined favorite travel routes. Seeing no message, Dan knows that, despite the typical heavy traffic, his usual I-66 route is his best option.
Jennifer is finishing up her work for the day at the National Postal Museum and is just about ready to head to her car to start her trip home to Alexandria when she decides to check traffic conditions on the 511 Virginia website. Jennifer knows she faces two route options as she crosses the Potomac on I-395: either stay on I-395 or exit off onto US 1. Seeing that there are no unusual conditions on either road, Jennifer decides that she'll probably take her usual route, staying on I-395. Thirty minutes later as she is nearing her decision point, Jennifer checks the 511 Virginia phone system for an update and is alerted of a recent incident on I-395. Based on this up-to-the-minute information, Jennifer decides to take her alternative route, US 1.
Tier II - Activity Areas:
