Caltrans, which designs and manages the state's major roadworks, is widely respected around the world for its engineering prowess and professionalism.

ECONOMIST: High-speed trains

TomTom's real-time driving community automatically detects road closures and roadworks even when they are not reported by official sources.

ENGADGET: TomTom announces HD Traffic upgrade, BMW Partnership

In January Transport for London introduced a permit scheme, adopted by 18 of London's 33 councils, which meant companies would need permission before beginning any roadworks.

BBC: Utility firms 'should pay rental for London roadworks'