How Individual Drivers Contribute to Smooth Traffic Flow
Last reviewed: 2026 · Driviology Road Safety Education Team
Quick Answer
Maintaining a consistent speed and avoiding unnecessary braking helps prevent the ripple effect that causes "phantom" traffic jams - slowdowns with no actual cause like a collision or lane closure.
Where our guide to reducing traffic congestion focuses on habits at merges and busy points, this page focuses on the steady-speed contribution to overall flow on open roads.
What Causes a Phantom Jam
One driver braking slightly harder than necessary causes the driver behind to brake harder still, and the effect ripples backward, eventually stopping traffic entirely with no actual incident at the source.
Maintaining a Consistent Speed
Holding a steady speed rather than repeatedly accelerating and braking reduces how strongly this ripple effect builds as it travels backward through traffic.
Leaving Enough Space Helps Too
Extra following distance gives room to absorb small speed changes ahead without needing to brake hard, connecting back to the everyday value of a safe following distance.