StopandGoVerkehr

StopandGoVerkehr, often described in English as stop-and-go traffic, refers to a traffic condition in which vehicles repeatedly accelerate and brake, producing alternating periods of movement and complete stops. It typically occurs at relatively high traffic density when road capacity is insufficient to maintain smooth flow, especially on urban arterials, freeways near bottlenecks, and at incidents or heavy merging zones.

Causes include bottlenecks, traffic signals, incidents, lane reductions, ramp merging, weather, and varying vehicle speeds. Small disturbances—such as a single vehicle braking gently—can amplify as drivers react, creating backward-propagating shockwaves along the line of traffic.

StopandGoVerkehr is a manifestation of unstable traffic flow. In many models, as density approaches the roadway's capacity, average speed declines and fluctuations grow, leading to repeated stopping and starting, sometimes forming what drivers call phantom jams even when no obvious obstacle is present.

Effects include longer travel times, increased fuel consumption and emissions, higher risk of rear-end collisions, and driver fatigue. The phenomenon is a common subject of traffic engineering and transportation research worldwide.

Mitigation approaches focus on maintaining stable flow: adaptive traffic signal control, ramp metering, variable speed limits, and synchronized traffic management; lane management and construction-zone design; improving incident response; and, in the long term, deployment of connected and automated vehicles to dampen disturbances and smooth traffic.

Related terms include stop-and-go waves, phantom jams, and traffic oscillations.