We already have different speed limits for different users in some highways (for instance, one major highway near where I live has a limit in some places of 110

We already have different speed limits for different users in some highways (for instance, one major highway near where I live has a limit in some places of 110 km/h for cars and 90 km/h for trucks and buses), so there's precedent. But I believe that, at least initially, speed limits for self-driving vehicles will be lower.