According to a recent survey, three out of four car drivers say they would buy a car that automatically cuts and restarts the engine in traffic to offer fuel savings of up to 8%. 

The technology is already in production not widely available. 

It also offers a parallel cut in CO2 emissions. 

The survey, by Motorpoint only covered car drivers but the reaction amongst van and light truck operators doing urban work would probably be similar.  

In practice, the technology - essentially a beefed up starter motor and enhanced engine electronics - stops the engine when the driver comes to a halt and takes the vehicle out of gear. 

Pressing the clutch automatically restarts the engine.