Design the 511 system to handle the surge in call volume during major events.
A national experience with the development and deployment of 511 Systems.
Made Public Date


Salt Lake City
United States


United States

Implementation and Operational Guidelines for 511 Services, Version 2.0


In March of 1999, the U.S. Department of Transportation (USDOT) petitioned the Federal Communications Commission (FCC) to designate a nationwide three-digit telephone number for traveler information. In July 2001, the FCC designated 511 as the national traveler information number. As of July 2003, nineteen 511 services across the country are operational and many have learned valuable lessons on deploying and operating systems.

In early 2001, the American Association of State Highway and Transportation Officials (AASHTO), the American Public Transportation Association (APTA), and the Intelligent Transportation Society of America (ITS America) with the support of the USDOT established a 511 Deployment Coalition. The goal of the Coalition is that 511 will be a “customer driven multi-modal traveler information service, available across the United States, accessed via telephones and other personal communications devices, realized through locally deployed interoperable systems, enabling a safer, more reliable and efficient transportation system.” In September 2003, the Coalition published the Implementation and Operational Guidelines for 511 Services, Version 2.0 to assist implementers in developing quality systems and increasing the level of operational knowledge among the 511 community. The lesson below is gathered from this guide, which has captured the experiences from many of the existing 511 services nationwide.

Lessons Learned

Experience from early deployers has found that the majority of 511 system usage will be driven by specific major events. These events will most likely be weather related, but they could also include major construction, planned events (e.g., a baseball game, a concert) or incidents.

A major event is a true test of the systems ability to provide a safer, more reliable and efficient transportation network while providing outstanding customer satisfaction. If the system fails during a major event, credibility is lost and agencies have a difficult time recovering. Major events will not occur often, but designing the system to handle these events will help to assure the successful deployment of the 511 system.

The following examples are provided by early deployers for the benefit of future deployers and are presented in the Coalition’s Implementation and Operational Guidelines for 511 Services, Version 2.0.

  • Plan the system to handle an extremely large call volume during inclement weather conditions. For the first five months of operation, the Nebraska 511 system, which focuses on weather-related roadway information, experienced a steady growth in usage as the winter of 2001-02 progressed. From October 2001 through February 2002, the system averaged 25,000 calls per month. However, March brought significant snow storms to the entire state and the system recorded over 103,000 calls, a 400% increase over the monthly average. For the next 15 months, the system never had to meet that demand again, but due to careful planning; the system has proven itself capable of handling extremely large call volumes.
  • Use the 511 System as a tool during major planned events. While most major events around the country tend to be weather-related, or incident related, some are planned events, like the Winter Olympics held in Salt Lake City, Utah in 2002. Utah DOT developed the 511 service with special content features designed specifically for the Olympics. These features included driving directions to venues, event schedules and tips for commuters. The service also offered a link to transit services and provided roadway conditions for the area. In all, the Olympics were a significant and immediate successful test for the system.
  • Use the 511 System to broadcast messages during emergency situations. As more 511 systems are being deployed, implementers continue to find additional ways to use this valuable resource during major emergencies. These situations have included major incidents, evacuations, and AMBER Alerts. The 511 service also offers the potential to become a valuable medium to provide travel information in support of homeland security emergency management. This potential is likely to increase in the coming years as more systems are deployed and familiarity with such systems continues to grow across the nation.

This lesson points out that a successful 511 system needs to be designed to handle a large volume of calls that may occur during major events such as severe weather, special event venues and emergencies. Performance will have a significant impact on the 511 system that can handle the demand during a major event. Reliable customer satisfaction will most likely result in repeat customers to the system in the future whether it be for a specific event or normal commuter travel. The more users the system has, the higher the potential for safer, more efficient travel.

Implementation and Operational Guidelines for 511 Services, Version 2.0

Implementation and Operational Guidelines for 511 Services, Version 2.0
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511 Deployment Coalition

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