A significant body of research has indicated that the use of hand-held cellular phones in moving vehicles can create a dangerous distraction to drivers in urban areas. Cellular phones with headphone interfaces may create a lesser, but still significant distraction. No research has yet explored the use of these phones by drivers on less congested rural roads where the driver’s workload is lower. The national “511” highway information system is heavily used by drivers, especially during inclement weather, to plan and replan their trips. While the system can be accessed by most telephones and authorities agree that users should call from home or from the roadside, a primary user group includes drivers who will access the system while driving on the roads. Few studies have explored the usability of the 511 user interface; we could find no published studies that have investigated the usability of 511 in the context of a mobile phone user who has the added workload of driving a vehicle.