I was surprised how long it took me sometimes. That is the reason that I use 350 miles a day or less as a rule of thumb, since I am the only driver. Driver fatigue can sneak up on you. For the 34 days in which I wrote down the times I left and the time I arrived on site, I averaged 40% over the time predicted by Mapquest. Included in this time were short lunch breaks and bathroom breaks but no days with longer stops. There are multiple reasons for the overage – weather, traffic, road construction (common in northern states and mountains during the summer), back up due to accidents, etc. Also, Mapquest assumes you will be driving the speed limit. The speed limit may exceed 65 mph in some states out west and but almost all trailer tires are limited to 65 mph. Another problem was finding the camp ground (GPS was not accurate for more than 10% of the campgrounds. You could get close but then had to hunt). I found a solution for this in 2017 by looking at Google Earth and finding the GPS coordinates for the entrance to the campground before I left home and using that on my car GPS. It worked great (but do not use the GPS coordinates for the actual specific campsite – this may send you down a road next to the park – it happened to me).