Comparing the quality of routes in navigation

When you enter a source and destination in Google Maps, it shows you multiple routes to reach from source to target. We have come up with another system that displays multiple routes from the same source to the same target (but these routes are different than those provided by Google Maps). The aim is to report alternative routes to the users that are similar in terms of travel time but are significantly different from each other in terms of the roads travelled.

We want to compare the "quality" of routes generated by our approach and by Google Maps. Specifically, we want the users to evaluate which of the two approaches report more realistic and meaningful alternative paths. We plan to show the routes generated by the two approaches for multiple source-target pairs and ask the users to choose whether approach A is better, approach B is better or both are similar. I am not sure whether this is an acceptable approach and if there are better approaches. Any suggestion will be highly appreciated.