Has market for CC shrunk?

[Kevin] Molloy says people who come to the convention center are part of the “rubber-tire market” that lives two or three hours away and can drive here at a time when many people are cutting back on travel expenses.

Could someone explain this to me? I thought it was meant to be a convention center. Now it’s limited to people who live two or three hours away?

Why would they come to a convention center?  For what events?