Define Central PA. I live in Center City and I drive. I suspect most people drive rather than walk. If you park on Vine or a nearby street, it is only three or four blocks to VIP or ADH/Grey.
Locked, during the day? That's odd.
I'd call ahead. In fact, best move is to call ahead to get a lineup. You're far less likely to get a pick (and they cycle girls in and out rather quickly) if you just show up, and having a choice is always better than not having a choice. That's capitalism, isn't it?