I am a firm believer in hours. With unfavorable traffic conditions a person could spent 8 hours behind the wheel and only travel 200 miles. I personally believe that limiting hours is a safer way to be sure the driver will stay fresh and alert. Professional truckers are restricted to the number of hours they are legally allowed to drive.
Unless I have a good reason I have a specific time in mind when I call it quits for the day which can be anywhere between 4 PM and 7 PM. My goal is to be registered and hooked up at a camp site before it gets dark. Usually I'll start searching for a place to hook up between 3:30 PM and 6:00 PM. Sometimes I'll plan on just pulling into a rest stop at about 6 PM which give me time to walk and feed the dogs make a sandwich or heat up a can of something on the stove and settle in and read a book before going to sleep.
Does anyone else try to calculate their hours rather than miles?
2014 4 WD Silverado 403 CI diesel long bed dually, B&W hitch with 95 Gallon Auxiliary Fuel Tank, pulling a 33 foot Holiday Rambler Alumascape suite, Winegard SK-3005 TRAV'LER slimline dish, Splendide 2100 XC washer dryer, TST Tire Pressure monitor system.