Originally Posted by njd1

Remember that the callout time means the time by which you must be at the gate. If you are a two hour drive to the airport, that's not going to work since you still need to catch a bus to the terminal from the employee lot (at EWR that's 10-15 min, depending on whether you catch it at the right time), get through security (2 min KCM, potentially 10+ if you're randomed), and walk to the gate (10+ minutes if you're stuck at the far end of the terminal and have to take yet another bus to get to an aircraft on a stand as opposed to a jetbridge.