I was on a B2B out of Baltimore back in January 2020, and used turnaround day to walk to the Baltimore Museum of Industry on Key Highway. At that time, the walk was very easy and (IIRC) there were sidewalks all the way. On the return, a guard directed us to the car exit gate (straight up from the west side of the terminal building) - just walk in front of the terminal to the luggage drop-off point before entering. If the weather is reasonable, it should be an easy walk.