Raj Rajkumar of Carnegie Mellon University in Pittsburgh, Pennsylvania, identifies multiple ways in which companies can build maps for their robot cars. The first is Google’s “do everything” approach: the company controls its entire driverless car operations, gathering the map data itself and processing it for the intelligent software that drives its cars. Google could use Street View to get its map data, collected by a dedicated fleet of cars. But it’s expensive and impractical to run Street View cars for the sole purpose of repeatedly scanning roads to keep maps up-to-date. For example, Street View has mapped a busy street in London, the A201 next to St Paul’s Cathedral, seven times since it began in 2008. But the street I live on, in a Greenwich suburb, has only ever been mapped once, last year.