Emergency Transportation Operations
photos of traffic merging onto congested highway, congestion in snowstorm, variable message sign, cargo, variable speed limit sign in a work zone, and a freeway at night
Office of Operations 21st Century Operations using 21st Century Technologies

Incident-Specific Traveler Information

Providing incident information to the public can dramatically reduce the impact of highway incidents on traffic movement by allowing motorists to take alternate travel routes, change departure times, or otherwise modify their travel plans to avoid incidents. Common technologies and methods used to provide incident information to the public and divert traffic include:

  • Predetermined alternate routes
  • Distribution of traffic incident information to radio and television outlets
  • Dynamic message signs along the roadways
  • Highway advisory radio broadcasts
  • Traveler information internet sites
  • Pager and broadcast fax alerts
  • Traveler information telephone numbers

Many media outlets are oriented to the news value of an incident, particularly a spectacular one, and do not provide information that motorists can use to make good decisions about the use of alternate routes. However, media information usually describes the general location of the incident, but often does not provide specifics about what ramps or streets are impacted. It is also common to see message on dynamic highway message signs that say "Congestion Ahead," or "Accident at X, Expect Delays." These messages are perhaps better than no notification at all, but provide very little useful information. Motorists may prefer predictable travel times to shorter delay-free travel in major urban areas, given that delay free travel is virtually impossible. Finally, some private sector information service providers (ISP) provide traveler information to subscribers and to media outlets. Many of these ISPs also have their own traffic monitoring equipment to supplement information from public sector sources.

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