Significant savings can be achieved through route optimization. A key first step is to know your costs. Only when you know those cost, can you start to control them.
Time is money and time only marches on. Once a minute has passed, that minute is no longer available for any productive use. In the world of route planning, there are way too many opportunities to have unproductive minutes. Doing manual repetitive tasks or planning less than the best routes can yield quite a bit of time that could be spent elsewhere.