Perhaps you missed the part where I explain my reasoning...
MOST of the base workers head north on 235 after working. It would make sense that this would be the time they would be stopping for groceries, quick pick-ups, etc.
Of course I didn't miss it.
And that's relevant if most of the base workers live FAR from the base that they might shop for groceries on the way home.
Unless of course, they live as far north as Charlotte Hall or further, in which case, they won't bother. They'll shop near home.
So - people who live in Mechanicsville or thereabouts.
Or if they're driving home to Leonardtown - where they will buy groceries THERE.
If they live in Hollywood or California - the store is right near home.
Work doesn't really figure into it.
Secondly - it's an easy thing to turn into Shopper's or Giant or WalMart or Weis at the light - and get back out and head north.
Harris Teeter - not so much. Not terribly convenient.