The Routing API routing engine prioritizes links included in the route for travel time during the day, link distance, other features, and traffic information (if enabled).
Most use cases need a route with the fastest travel time, which you can request using the
fastest routing mode, however there may be times when it makes sense to choose another routing mode. Types prioritize these elements as follows:
fastest: routing favors the least amount of travel time, can consider traffic if enabled. This is the most commonly used routing type.
shortest: routing favors the least amount of travel distance, disregards traffic