Question: What does Rogue Improved Trap Sense actually do?

[dapaperboy]

http://compendium.ddo.com/wiki/Enhancement:Rogue_Improved_Trap_Sense_I

I'm not fully understanding what this enchantment does. Isn't the +2 bonus only applied when you get hit/affected by a trap because it's a save against it (I'm thinking that the +2 bonus works like a saving throw against traps). Then why is it called "improved trap sense" if it's only applied when you get hit/affected by one and doesn't improve your trap sense? Please explain this :/

[Hobgoblin]

if your reflex save is 20, if you roll for a spell you add 20 if you roll against a trap you roll 22

make sense?

hob

[Tirkan]

Rogue Trap Sense is, and always has been, an ability that increases your chance to get out of the way of a trap.

It's called that because you get a 'split second' warning, a 'sensation' if you will, that Something Bad is about to happen to you if you don't get out of the way.

Would you like it better if they called it 'Improved Spider Sense' instead?