Use the Distance Matrix API to find the closest taxis based on drive time and drive distance
Performing a simple radius or “straight line” distance search to find the nearest available taxis can often provide misleading results. For example, a taxi may be on the far side of a highway or the other side of a river and take a long time to drive to the pick-up point. The D istance
Matrix API can calculate the driving distances and times, based on Google’s road network, to improve the accuracy of your search results.
The distance matrix API can also make use of the real time traffic information provided by Google which can improve the matches between drivers and customers.
Also if you have multiple vehicle types available, you could use the Distance Matrix API to show the closest of each of these types so that the user could make an informed decision not only on time they would take to come but also on the type of vehicle to hire also.