A recent article in MIT's Technology Review magazine finds that spontaneous traffic jams - slowdowns in heavy traffic that happen without an obvious obstacle - could be reduced if vehicles maintained equal distance between a slowing car ahead and the one right behind.
This would prevent what normally happens when one car brakes sharply: the slowdown propagates back with increasing amplitude.
The researcher hopes to avoid this through future widespread use of adaptive cruise control and front and rear facing cameras.
But it's pretty close to the way I drive my Volt now on freeways. It's always in L, so as soon as I see the car ahead slow down I back off the accelerator, checking the rear view mirror to calibrate how rapidly it's safe to slow down. This absorbs much of the braking car's speed change, reducing the propagation of the slowdown.
Yet another way that Volts make the world better.