HL2 Crashes when i open a map

This is basically "how do I determine if my hardware is stable?"

Sounds like you've already tried

• making sure your video drivers are 100% up to date

• monitoring temperatures (though you should try the "open case with house fan blowing on it" to make absolutely sure)

But you have not tried

• removing ALL overclocks: CPU and GPU. Make everything run at absolute stock speeds to reduce variables.

• disable CrossFire in the drivers so you are only running on one video card, not two: does it still happen? (no need to physically remove the 2nd card, disabling CrossFire in the drivers should work)

The standard "is my system stable?" tests should be run:

• run Prime95 overnight and see if your CPU is stable

• run Memtest86 overnight and see if your memory is stable

• run Furmark for an hour or so (be careful as this thing loads GPUs far beyond any realistic load)

Warning: Battlefield 3 is known to be extremely GPU intensive and may cause more heat than most games.

Are you referring to this area?

This does sound like a bug. That doesn't normally happen, and the doorway pictured above is the correct path to take.

Verifying the game's files is probably the best course of action. (Step 1, and Step 2 - Select Half-Life 2 instead of Counter-Strike as pictured)

Edit: As noted in the comments below, the poster found that the solution was to restart the chapter.

Images from: http://www.visualwalkthroughs.com/halflife2/highway17/highway17.htm