because flight times are subject to the winds which vary, using the scheduled times gives you an approximate time [deduct for taxi time]...as for routes not flown non stop, you could extrapolate from sked'd trips using the point to point distances between cities. this can be determined from www.webflyer.com. also, flights may not fly a great circle route because of air traffic control, winds, avoiding restricted areas etc. anyway, i don't know of a site that will do what you want...good luck