AmateurRadio.com

Have you ever wondered where those odd stations found at the ends of the AM broadcast band might be located and what they're all about? These are 'Traveller Information Stations' or 'TIS's and, 'Highway Advisory Radio' (HAR) stations. Because of their low power (100mw - 10W), they make challenging DX targets if you can catch the ID on their continually- repeated audio loop.

These stations are located throughout Canada and the USA at places such as highway intersections, border crossings, ferry terminals, airports and parks ... just about any place that needs to advise travellers (vehicles) with up-to-date directions or information. From here on Mayne Island, the farthest TIS I have been able to identify was WPTC509, located in Carbon County, Wyoming.

courtesy: https://www.google.ca/maps

Thanks to the International Radio Club of America's (IRCA) Phil Bytheway, an up-to-date list (58 pages) of all known stations is available for download or, if you choose, as a purchased hard copy.

 IRCA TIS/HAR LIST (Winter 2016)

The IRCA TIS/HAR LIST lists all US and Canadian TIS/HAR stations, by frequency, including call letters, state (province,) city, county, licensee, address, coordinates, expiration date and dates of DXM/DXN reports/sources. It has been updated with FCC data, DXM, DXN and DXer reports, and on-line listings through March 1 2016.
The 2016 IRCA TIS/HAR LIST is posted on the IRCA website for all to download. The link is: http://www.ircaonline.org/TIS_2016.pdf.
For those preferring a hard copy, one can be ordered from the IRCA.
 
As well, this page on regulations, permitted content and TIS history has some interesting info.

IRCA is one of the oldest clubs dedicated to DXing the broadcast bands and members receive a monthly journal of members loggings as well as other relevant articles. A trip to the IRCA website might get you hooked on this part of the radio hobby as it's probably the way that most amateurs discovered the 'magic of radio', on late winter nights! Just in case you need it,  the mwlist will help you identify any stations heard in the AM broadcast band, worldwide.