Got a little dizzy driving in circles to the floors with availability, but this is probably the best option for a reasonably priced covered parking garage at BWI ($12/day). It's a huge garage and has availability most of the time (even when the cheaper express and long term parking lots are full, this has had plenty of availability.
After you park, there are a few bus stops on level 2 that have busses every 10-15 minutes to take you to the terminal. I waited about 7 minutes and it's a quick trip to the terminal.
If you don't care about having a covered garage, the express lot is a cheaper option that has similar service. And if you want to be closer to the airport, the more expensive hourly lot is the choice for you. You can pay before you drive out at the pay stations on Level 2 or just way at the gate on your way out. Will definitely use this lot in the future. read more