if the other unions strike, they could shutdown every aspect of the city - including the schools.
that's not to say this is being handled well - I do not understand why they haven't hired every private bus they could find and massed them at collection points in the suburbs where people can park, and load them onto buses that would make 3 or 4 stops in key parts of the city. the HOV4 rules are not working, all the legitimate traffic (with 4 persons) is bottled up behind the checkpoints, so traffic inside the "box" is actually far less then it usually is, so this plan is not allowing for good utilization of surface transport - its all backed up behind the checkpoints.