Having just raced at a track with allot of unprotected concrete and lived to tell the tale.....I guess I don't have an answer for you.
If it makes you feel better the Labor Day event is the only time IT cars will get to race at HPT next year. The other event is a Double Natioal (first weekend in May).
i've ran Gateway twice, and HPT maybe eight weekends and haven't had contact with a wall either. but i'd much rather not run at these types of places if i can avoid it. if i didn't run HPT even once in 2009 i wouldn't be much disappointed.