30 is dangerous if you are not wearing a helmet or hit a kerb with your pelvis.Remarkably difficult for your average punter to get up to a dangerous speed on a bike in a reasonably well populated area mind.
One thing which could be helpful for motorists and cyclists is to ban jaywalking like they do in some German states (or all of them?).
You’re never going to get rid of the risk of injury in any form of transport but you can manage that risk better by slowing down