Drafting - don't try this at home

The university I graduated at was working on an automated driving system. The cars relied on radar to keep their intervals and little modules on the road. That was about 10 years ago. They even did a test where the cars (about 5) drove up to 60 mph only a couple feet apart and slowed down and sped up accordingly. The study was primarily on an autopilot system so I am not sure the interval technology was used for something else.

I am an aero engineer. We did a study that when cars/trucks drive abreast they create a unified pressure front and each vehicle shares the drag. Bad for us good for big trucks. I cannot remember the distance but as far as drafting you should see an improvment 4-6 car lengths behind a semi (but then that was a simulation so not sure how accurate it was), which is a safe distance. Just watch out for tons of crap off their back wheels.

Due to the angle of our windshield if you drive 60 most stuff will deflect. When I get up to 70-75 it either cracks or chips my windshield.