Location APIs let other companies' software use a digital map, so that a fleet, a delivery company or an app can find addresses, plan routes and show maps without building a map of its own. The map provider's service that offers them is called a location platform. An API is a fixed way for one program to send a request to the map provider's servers and get an answer back. The request may be an address, or two points on the map. The answer is a position, a route or a travel time.
A location platform offers a handful of standard services. Geocoding turns an address into a latitude and a longitude. Reverse geocoding turns a point back into an address. Routing returns the best route between two points and how long it should take, with rules for trucks, such as low bridges and roads closed to heavy vehicles. A travel-time matrix returns the time between every pair of points in a list. Search finds places by name. Map display sends the map images that an app shows on screen. The company usually pays for every thousand requests.
Take, for example, a parcel delivery company in Delhi that delivers 40,000 parcels a day. At 6 a.m., its system sends all 40,000 addresses to the geocoding service. Each answer comes back with a position and a confidence score, which says how sure the service is. About 36,000 addresses come back with a confident position. The other 4,000 are written in ways such as "Gali No. 4, near the old water tank", and they get low scores. The company's support team confirms these by phone with the customer, or with the local delivery rider. Data quality software can clean many such addresses before they are sent.
Next, the system asks the travel-time matrix for the time between every pair of stops in each area, at the traffic expected at 10 a.m. These are times by road, not straight-line distances. A shop 500 metres away across a railway line may be 15 minutes away by road. Route optimisation software uses the times to build about 400 routes, of about 100 stops each. During the day, if a road is closed, the routing service returns a new route to the rider's phone.
Ride-hailing apps use the same kind of service in a different way. Their ride dispatch system asks for travel times from every nearby driver to the rider, and offers the ride to the driver who can arrive first by road.
Why not build a map instead? A map of a whole country must be surveyed and updated every day, which only a few companies can afford. A location platform lets a company pay only for the requests it makes. It sells the same data as the digital map, delivered as answers to software instead of as a map for a screen.