Two seconds is an eternity depending on your speed. If you can’t see two seconds of travel ahead, you better not stop paying attention for that time.

It's true, as exemplified by a scratched bike.

Still, it happens, and the designer of the infrastructure must be aware of that.

To take the devil's advocate role, people will keep traveling long after they exhausted their ability to pay attention, and/or keep reasonable distance from the next one in the front.

> people will keep traveling long after they exhausted their ability to pay attention, and/or keep reasonable distance from the next one in the front

While this is true, we haven’t stopped selling knives because a few people use them irresponsibly. By the same token, we shouldn’t discount infrastructure because a few people drive when they shouldn’t.