What happens with me, before:
Try 1- Timed Out
Try 2- Connection problem when on
Try 3- Crash
Now here's what happens
Try 1: Timed out, maybe lucky to get on
Try 2: Get on, connection problem
Try 3: Very rare crash, get on
Try 4: I've never had to try 4 times.
Also, I believe server traffic has nothing to do about this.
I believe it depends mostly on how many props are spawned in the server, and everything's gotta load in time, and your computer can't catch up!
Also, it is not based on luck.
Tweaking graphics settings would be the best way to solve this problem.
I had to go into my brother's Intel graphics panel and turn the 3d Graphics to the performance setting, and now he gets on easier.