Traffic Waves - a #Visualization

Lewis Lehe and Matthew Greene over at KQED have a complete description of traffic waves, and a sweet visualization to go with it.

The simplest explanation for why traffic waves happen is that drivers have relatively slow reaction times: if the car in front of you suddenly slows down, it’ll likely take you a second or so to hit the brakes. The slower your reaction time, the harder you have to brake to compensate and keep a safe distance. The same goes for the car behind you, which has to brake even harder than you did in order to slow down faster. And so on down the road, in a domino-like effect.

To illustrate this concept, programmer Lewis Lehe, a civil engineering graduate student at UC Berkeley, created this visualization. Select a car from the bunch, click “Hit the Brakes” to slow down your highlighted car, and then wait until a traffic wave forms. The red bars represent deceleration levels (braking) and the green,  acceleration (speeding up). Mouse over a car to slow everything down see its velocity and acceleration at any given point during the wave (assuming all the cars are in the same single lane). 

Check it out (and for the full article, go here...)