[jvriezen]

An even better safety approach is a 'dead man' switch. This requires a person to continuously hold a switch in the pressed position for the robot to operate. Of course you couple this with a policy that you never jerry rig the switch to be held other than by a human watching the robot.

Basically every push lawn mower has one of these on the handle, and every riding lawnmower has a seat switch that does the same thing (at least when the blades are spinning.)

Update: Clarification: I agree, driving in the pits is not appropriate. My suggestion above is more for driving in the shop and could even apply to driving on a practice field, which is more danger prone than a real field. Seems like it would be a good idea to have a driver station setting that allows you to invert the space bar, and require that it be pressed when enabling and result in a kill if released while enabled.