2003 Civic Intermittent High Idle???

The other day when sitting in stop and go traffic, my civic idle jumped up do 2500 rpm when i was in gear. It was like this until i got off the interstate and drove awhile. At the next stop it was fine, no check engine light or dtc's. Any ideas?????

I have a 2002 Accord V6 and the idle speed would oscillate up and down. It turned out to be a dirty Idle Air Control valve.