I’ll go for a serious answer.
When driving, particularly on freeways and highways, everyone must now leave a lot of space between them and the car ahead proportional to how fast they are going - even in heavy traffic. And they must allow a car that is signalling properly to merge into their lane. (But not like a bunch of cars at a time of course)
Everyone must also start to decelerate as soon as they see brake lights ahead or notice slowing, but they have more space (starting further back in the road), so won’t have to decelerate as strongly as the car ahead is and will reach a higher minimum speed or be stopped for less time when the car ahead starts accelerating again.
I believe this would mostly end stop-and-go traffic and smooth out all slow traffic (increasing fuel economy and reducing stress) by reducing/eliminating traffic waves. Probably even increase average speeds (but I’m less sure about that)
https://youtu.be/kCpjgl2baLs?t=1m9s