trucks equipped with gps satellite navigation units have enabled drivers to forgo a traditional paper-based map, saving time and effort. drivers willing to pay for satellite radio or who work for a company that pays for it can listen to commercial-free music, sports, news, and talk radio coast-to-coast without interruption of signals between cities (as terrestrial radio signals are limited to a certain radius from the broadcasting tower). digital satellite television allows smaller dish sizes, which means truck drivers are not limited to free terrestrial broadcast television and have more options about what they watch during their off-duty periods.