This time it seems I crash on entrance to "The Strip" via Freeside.
A possible cause was completing the Debt Collector quest, which I did, in fact, complete, leading me to believe this is the reason for my constant crashes on entrance to The Strip.
One possible solution was using a monorail. I'll try this now, but I believe this should be in here, considering that door isn't meant to crash just because you complete a quest.
If there are any other solutions, I'd love to hear them. I'm using a vanilla Fallout: New Vegas.
PC Specs:
AMD Athlon II X4 630 Quad Core ~3.36 GHz
4 GB DDR3 RAM
nVidia 9800 GT 1 GB Dedicated RAM
Microsoft Windows XP Professional x64 SP2
New Vegas Settings on Ultra (Water Multisampling Low), full resolution, 2x AA 15xAF