Packing cars together and synchronizing them is probably the safer way. Less chance that a car, person or animal will get between two cars if the space between them is less.

How many pedestrians are killed by jumping between two train wagons?

I would rather we take small step, and frankly deer have no problem jumping into groups of cars or even between semis and their trailers. They are not a situationally aware animal.

> How many pedestrians are killed by jumping between two train wagons?

How many tires blow out per year, or cars get slippery?

Fewer tires than they would if a computer checked their air pressure diligently.

Taking small steps is fine, but the smallness should be in the location, not the density. Just a small neighborhood with only self driving cars, instead of a large neighborhood with a small proportion of self driving cars.

And of course, a deer-free neighborhood will be best to start with.