To get information about the B & A trail being closed at Joyce Lane, I called the number Cindy left. The person who answered this morning referred me to the B & A Trails Office at 410 222 6141.  The trails office didn't return my call.
     Looking at the detailed AA County Street Map, it appears there are ways around the trail closure.  Southbound riders can turn left (TL) at Glen Oban Dr, about 1/2 mile before the trail closure.  Then  turn right (TR) onto RT 648 south that parallels the trail. Next  TR from 648 onto Little Joyce LA which ends at the trail.  If Little
Joyce looks too private, continue a little further on 648 and see if the short right turn to access the trail past the bridge closure works.  If not, TR onto Ritchie Hwy and in 1/2 mile turn right onto the ARNOLD SHOPPING CTR THAT CONTAINS THE AAA.  You should be able to pick up the trail at the rear of this shopping center. 
      Since children use this trail, the rangers are probably reluctant to suggest a way around the closure that goes a short distance on a busy road.

Regarding getting around the B & A closure, it appears that Little Joyce Ln doesn't go through to the Trail.  Therefore, you will need to continue south on Ritchie Hwy a short distance to Arnold Rd, where you turn right to pick up the trail.