In Texas, they implement "hurricane lanes," which just means during disasters, you can legally drive on the shoulder. In practice, I've seen it where all lanes

In Texas, they implement "hurricane lanes," which just means during disasters, you can legally drive on the shoulder. In practice, I've seen it where all lanes are made outbound-only. If you live within 10 miles of a US Nuclear Facility like me, NRC requires they send an annual calendar marked with siren-testing dates and escape-route maps. You can request free iodine tablets, for use while you're irradiated in traffic. But IMHO both examples are mostly just coping mechanisms, designed to give panic direction.