thanks for all the suggestions.

i don't need a high end limo service. however, my main consideration is the tuesday morning trip between college park and IAD, which is during the rush hour. if i take the supershuttle, it's asking me to pick me up at 6:30am for my 9:40am flight. but i am not checking in luggage and really don't need to be at the airport that early.

if i take out a rental car, how long would it take from college park to IAD during morning rush hour? also i have never returned a rental car in IAD. would it take a long time to get back to the terminal from rental car counters?

again thanks for all the assistance!