5-1-1

5-1-1 is a transportation and traffic information telephone hotline in most regions of the United States and Canada. Travelers can dial 511, a three-digit telephone number, on landlines and most mobile phones. The number has also extended to be the default name of many state and provincial transportation department road conditions Web sites, such as Wisconsin's site. It is an example of an N11 code, part of the North American Numbering Plan.

5-1-1 services in the United States are organized by state or region. Some 5-1-1 services are limited to information for drivers regarding road conditions and traffic. Other services have a wider scope, also providing information on public transport, carpooling and other services.

Beginning as a research project at the University of North Dakota in the Summer 1995, an Advanced Traveler Information System, known by its phone number #SAFE (#7233). This initial system provided the proof of concept for a statewide application across both North and South Dakota, and later Minnesota. This system proved that all interstates, and state highways, could be covered and information about these roadways could be provided to travelers on demand 24/7. After more than 5 years of around the clock operations, the principles that established the operational and business rules of the #SAFE program were adopted by the FHWA as the initial guidelines of what was to later become 5-1-1.

In March 1998, a 3-digit dialing code was launched in the Cincinnati–Northern Kentucky metropolitan area for the ARTIMIS project. The SmarTraveler service, operated by SmartRoute Systems for the Kentucky Transportation Cabinet since 1995, had been using a 7-digit code (333-3333) which was available to landline phones in both Cincinnati and Northern Kentucky area codes, but cellular callers had to dial a separate code (*1) to access the same touch-tone traffic system. SmartRoute Systems and KYTC negotiated with the two active cellular carriers and Cincinnati Bell and reached an agreement on allowing a 3-digit code "2-1-1" (a number agreed by the carriers), making this the "first in the nation". This implementation was seen as proof that wireless carriers could implement short-codes without a * or # prefix requirement, and led to a series of discussions with the USDOT and the FCC pushing the carriers to release the number (which they viewed as precious internal resources).

On October 2, 1996, Eli Sherer of SmartRoute Systems, along with representatives from ITS America, the USDOT Joint Program Office, and others met with the FCC regarding the possibility of reserving an N11 number nationwide for Advanced Traveler Information Systems. This meeting led to further discussions at ITS America and USDOT, and the information provided was used and molded into the USDOT petition to the FCC for a 3-digit code for ATIS. The USDOT petition (as noted below) did NOT request a specific N11 number; When the FCC ruling was made on July 21, 2001, the 511 code was "ASSIGNED as a national abbreviated dialing code to be used exclusively for access to travel information services," and at the same time, the 211 code was "ASSIGNED as a national abbreviated dialing code to be used to access community information and referral services." Therefore, the 211 code that had been in use in Cincinnati since 1998 was changed to 511.

As of March 2001, at least 300 telephone numbers existed for travel information systems in the United States. To overcome the confusion caused by this array of numbers, the United States Department of Transportation (USDOT) petitioned the Federal Communications Commission (FCC) for a national assignment of a single three-digit N11 dialing code. On July 21, 2000, the FCC assigned 511 as a nationwide telephone number for intelligent transportation system (ITS) traveler information, along with 2-1-1 for social services. Its use is being promoted by the USDOT's ITS initiative.

"On March 8, 1999, the U.S. Department of Transportation (U.S. DOT) petitioned the Federal Communications Commission (FCC) to designate a nationwide three-digit telephone number for traveler information.
On July 21, 2000, the FCC designated 511 as the United States' national travel information telephone number."

The first 511 traveler information system to launch was the Cincinnati area's ARTIMIS hotline in June 2001.