Explanation: Coasting is the term used when the clutch is held down, or the gear lever is in neutral, and the vehicle is allowed to freewheel. This reduces the driver's control of the vehicle. When you coast, the engine can't drive the wheels to stabilise you through a corner, or give the assistance of engine braking to help slow the car.
Category: Safety margins
References: The official DVSA guide to driving: section 5, Highway code: rule 122