Quote Originally Posted by Ascension View Post
A fairly standard convention is that a man can walk 10 miles a day, horse can go 10 leagues (30 miles). 3 months is roughly 90 days. 90 times 30 = 2700 miles. 4 months is 120 days = 3600 miles. Boston to LA is 2983. Your image is 3000 pixels wide so I would say the scale is about 1 pixel per mile.
For distance and travel time measurements, I look to the PCT (Pacific Crest Trail) and the usual travel times on that. It's a trail that follows the Sierra Nevada and Cascade ranges from Mexico to Canada. It's about 2600 miles long, and usually takes 5-6 months to complete. Most people cover around 20 miles a day. However, speed hikers often attempt an extremely light-packed version of the trail, taking barely anything with them, and some average 35-40 miles a day. For horseback, 20 miles a day is apparently considered leisurely (though I'm no equestrian, so take that with a grain of salt), and it seems that a horseback speed of about twice that of walking is reasonable. The record is, I think, just over 66 days walking. When thinking of heroic adventurers on an epic quest, I tend to judge their physical fitness, the distance required, the amount of gear required, and their haste, and use empirical PCT numbers to estimate their travel time.

All of that is to say, Ascension is essentially right; a scale of 1 mile:1 px is probably what you're looking for. I really like the look of this map style, and it seems that you've got it down pretty nicely. Well done.