Spline Editing

By changing where the dots are, the curve editor dictates on which frame an object will get to a location and where that location is, so essentially all it did was change at what frame the cars reached a certain y-position. Because of how our brains see it, though, it looks as if the cars are moving like real objects do (except for the pink one.) 

What would be called the "bezier curve," which is essentially just easing on both the start and end, making the car realistically (or as realistically as you can get) "accelerate" and "decelerate."

The only real challenge I had was changing the time that the cars got to their destination, since I didn't realize there were editable parameters at the bottom of the curve editor. I did accidentally give all the cars unrestricted changes before I read the car-by-car directions, but that was just a time sink.

This can mostly just be used for either manual slow-motion and acceleration/deceleration. If I want the a vehicle to start moving faster, I just go to the curve editor. This is somewhat true for all animated movements, just changing the acceleration and deceleration, though.