Take on mass hysteria

at I don't get is that cities and states do nothing but fan the flames of hysteria. Two decisions stand out:
-Bloomberg ordering the sensible evacuation of low lying properties by 5pm today
- The MTA shutting down train service by noon today

Does anybody see the issue here. The hurricane is not supposed to hit until late tonight yet we shut down mass transit a full 12 hours in advance. You are setting yourself up for a mass exodus using the main arteries out of the city. Cars will be backed up for a hundred miles on the BQE, the Henry Hudson and the thruway. It'll be like Woodstock without the free love and Jimi Hendrix.
Honestly I thought the idea was to avoid hysteria and then you tell 100,000 people to leave their homes and go into a shelter