Originally Posted by Alpha Golf
I've never waited more than 5 minutes at NW concourse at DCA, my home airport. So half an hour should be plenty. Walk to the gates is only about 3 minutes from there.
CO/DL/others can be much longer, specially Friday afternoons.
I disagree. I think the wait is 10 minutes on average, often closer to 20. Remember that NW shares this terminal with a couple of LCCs who tend to have more infrequent travellers.