Better than singing, turning up the radio, driving with the window down or stopping periodically for exercise, if you are too tired to drive, sleep is the only remedy. A 15 minute nap possibly coupled with consumption of some strong coffee might get you to a point where you can continue for another hour or two. There is no better position to be in than that of being well rested before driving.
Drowsy Driving – Canadian Sleep Society PDF
Cst. Tim Schewe (Ret.) runs DriveSmartBC, a community web site about traffic safety in British Columbia. For 25 years he was an officer with the Royal Canadian Mounted Police, including five years on general duty, 20 in traffic and 10 as a collision analyst responsible of conducting technical investigations of collisions. He retired from policing in 2006 but continues to be active in traffic safety through the DriveSmartBC web site, teaching seminars and contributing content to newspapers and web sites.