We use Directions API but a single route recalculation can generate up to 2000 queries, it is too expensive, how can it be optimized?

Our service is wanting a consistent result when selecting a route based on various factors. We simply are looking to understand if there is any order to the resulting routes in the response. Specifically whether or not travel time dictates that order.

Our service is wanting a consistent result when selecting a route based on various factors. We simply are looking to understand if there is any order to the resulting routes in the response. Specifically whether or not travel time dictates that order.