This issue is not limited to time sharing. It's equally inefficient to stack individual cars on highways during rush hours.

Public transport is the best answers, but even so rush hours is still hard to manage.

Rush hour is a global issue that could actually be mitigated by more flexible schedules and increase in remote work. So we shouldn't try to solve it by transportation alone.

Interestingly jobs that can't be remote (factories, etc) usually already use alternative schedules that avoid office rush hours.