rolling stop
An automobile driving maneuver in which a driver slows down, but does not completely stop, at a stop sign.
rolling stop: slowing down instead of stopping
A rolling stop occurs when a driver reduces speed at a stop sign or traffic signal but does not bring the vehicle to a complete halt, typically moving at 5 to 15 mph through the intersection. The vehicle's wheels continue turning throughout the maneuver rather than coming to rest. This differs from a legal stop, where the vehicle must achieve zero velocity and remain stationary for a measurable moment before proceeding.
In traffic enforcement, the distinction between a rolling stop and a complete stop is legally significant. Most jurisdictions define a stop as a full cessation of motion; rolling stops therefore constitute violations of traffic code. Law enforcement measures this using observation of wheel rotation, vehicle momentum, and the driver's apparent control of the vehicle at the sign or signal. Police typically cite rolling stops under the same statutes governing failure to obey traffic control devices.
Why the practice persists
Drivers perform rolling stops to save fuel, reduce engine wear, and decrease acceleration time, particularly in congested urban driving where frequent stops occur. At low speeds, the kinetic energy loss and fuel consumption reductions are measurable but modest. However, these minor savings come with increased accident risk; the driver's reduced control and visibility during a rolling stop makes collision with pedestrians, cyclists, and cross-traffic more likely. Insurance underwriters and safety analysts consistently identify rolling stops as a contributing factor in intersection collisions.
Autonomous vehicle systems are programmed to execute complete stops at designated control points rather than rolling stops, treating the legal requirement as a functional safety boundary. This rigid compliance reflects the liability exposure and the system's inability to exercise the judgment that might justify exceptions in exceptional circumstances.
The term emerged in common use during the 1980s as traffic enforcement and insurance analysis became more granular. It reflects a specific violation category rather than a technical driving technique, serving mainly as a way for enforcement and safety professionals to distinguish this behavior from either complete compliance or more dangerous violations like running a signal.