I don't see how it's safe to allow this for bikes, but it's not safe for cars? Why not just allowing everyone to "slow down and look for traffic" and then decid

I don't see how it's safe to allow this for bikes, but it's not safe for cars? Why not just allowing everyone to "slow down and look for traffic" and then decide if it's safe to go through or not? That's basically what you do when there's no traffic lights and if people really slow down and look there will be rarely any problems with that. That's how roundabouts function, and they are generally very safe.