They drive more conservatively than the most conservative human driver, mainly because they don’t try at all to cooperate with other vehicles. It’s clearly due to technical reasons, not because they’re being more safe.
For example, if they need to make a lane change for a turn on a congested street, they will wait for someone to let them in rather than “pushing” their way in like a human driver (especially a bus driver) would. When that inevitably doesn’t happen, they are forced to go around the block and try again.
That exact behavior happened during the “Uber” ride I took on a Waymo, and it is possible they have improved since then.
For example, if they need to make a lane change for a turn on a congested street, they will wait for someone to let them in rather than “pushing” their way in like a human driver (especially a bus driver) would. When that inevitably doesn’t happen, they are forced to go around the block and try again.
That exact behavior happened during the “Uber” ride I took on a Waymo, and it is possible they have improved since then.