The Silicon Valley race to build a self-driving car may revolve around one simple question: to map or not to map. The company at the forefront of the race, Google Inc, is creating intricate maps that detail every tree and curb along the road – an expensive endeavor that other companies could find difficult to match. Newer entrants such as ride-share service Uber and Apple Inc could take a shortcut and develop a car capable of piloting itself without such elaborate and expensive blueprints, industry experts say.