Car park users are increasingly complaining about receiving static shocks at car park ticket machines. Electrostatic charges can build up when a vehicle rolls along a road surface. This charge will most commonly dissipate to ground through the vehicle's tyres when the car is stationary. But in some instances, the charge is unable to dissipate due to the road surface having high resistance levels. In these cases, if a user is to touch a conductive and grounded object such as a ticket machine, they will receive a static electric shock.

In theory, the problem is easy to treat but in practice there are many factors at play. For instance, under dry conditions the instances of shocks will increase, this is due to the high resistance to ground and surface resistance to the floor. Other factors can also increase the amount of charge built up, including the speed at which a car travels, the characteristics of the tyre and the type of substrate. The worst scenarios are ones where a vehicle can travel at speed on an insulating surface, such as an asphalt ramp with no queue at a barrier which would allow the charge to decay before the user makes contact with the ticket machine.