This is good idea but could be done differently. One major issue is that time is not only the optimization criteria. For example, if there are two places both 3

This is good idea but could be done differently. One major issue is that time is not only the optimization criteria. For example, if there are two places both 30 minutes away but one requires me to take tons of turns through narrow streets while other is straight forward highway driving then I would chose the later. Hack I would later even if cost was 25% more. Others may have some other criteria, for example, eating near river shore instead of in dirty back alley. The bottom line is that you can't just throwaway physical maps. One way to marry your idea in physical may might be to color code places according to how far they are.