1. A method comprising: receiving, at a travel coordination system from a provider device, a current location of a provider that is available to transport a rider, the provider operating the provider device in communication with the travel coordination system; identifying, by the travel coordination system, a destination for the provider; determining, by the travel coordination system, a set of candidate routes from the current location of the provider to the destination; generating, by the travel coordination system for each candidate route in the set of candidate routes, a route score, wherein generating a route score for a candidate route comprises: identifying a set of zones through which the candidate route passes, determining, for each zone in the set of zones, an estimated wait time at an arrival time at the zone in the set of zones for the provider by traveling along the candidate route, the estimated wait time being an estimated amount of time the provider is expected to wait in the zone before receiving an assignment request to transport a rider in the zone, and generating a route score for the candidate route based on the estimated wait times for the set of zones; selecting, by the travel coordination system, a route from the set of candidate routes based on a route score corresponding to the selected route; and transmitting, by the travel coordination system, data of the selected route to the provider device.