Tripping rooms which are spawn points with one exit is considered a fopaux... and should be discouraged. Now I can see that the practice of setting trips near spawn points seem frustrating to some, specially for the players who run like their pants are on fire without a care... but this is the reality of the game. Its no more frustrating than someone dropping a nade when they spawn on the spawn point. just for the next to get it when they spawn.
All I can recommend is what your step... There is plenty of dog shit out there... lol
I don't drop my nades when I spawn or throw them to the spawn point, but there's a slight difference anyway. If somebody sets a trip half a step away from the spawn point, the kill is guaranteed. I like to gun and run and I hit many tripwires along the way, which is fine. What I'm taking bout is taking half a step and blowing up.... its slightly different imho...
As I stated before, there is a spawn protection for trips and mines, and it's more than a step or two.