Choice of route can save on gas. Shorter paths are generally better than longer paths, but there are complicating factors. For example, a shorter path which has you stuck in stop and go traffic could burn more gas than a somewhat longer route on an open road. Remember that slowing down or stopping only to speed back up again wastes all the kinetic energy which you had to pay for with fuel. There are various route planning programs which can help you deal with these factors. The video introduces one.