Akin to 911, 711 or 411, this three-digit phone number has been set up in the United State to allow people to gain access to information about transportation. Requested by the United States Department of Transportation and implemented by the Federal Communications Commission on July 21, 2000, 511 should help travelers make informed decision on what on routes and times to travel.
511 is one communication medium of the larger Intelligent Transportation Systems (ITS), which includes web sites, variable message signs and highway advisory radio. These systems are intended to give the traveler real time information on road conditions and highway incidents (such as construction, accidents or basically anything that impedes the flow of traffic).
Similar to 911, 511 is operated by State and local agencies and not the federal government. Also, there is no federal funding provided to implement or maintain information for 511. Because of this, the system is not yet in wide spread use, and may take 5 years (2005) to become commonplace.
Ideally, 511 systems will be computer driven (no live operators) with speech recognition, opposed to keying in commands by pressing a bottom on your phone. This is imperative to safety, as a lot of users will be calling from their cell phones while driving.
511 systems should be available to the public for free (excluding the taxes, of course). Although per-call fees are not prohibited, they are discouraged by the Feds. These systems have several benefits that are only effective if people use them and charging a per-call fee would be a great deterrent.
Sources:
http://www.itsa.org/
http://www.its.dot.gov/511/511.htm