I don’t ride out in that area much but I am relatively familiar with much of the drive from Glenmont to Ft Meade and a quick look at the Google maps suggested bike route confirms my thoughts. An awful lot of the available east to west routing is on some very heavily traveled and fairly fast commuter roads. The few stretches of bike path that Google found are not in areas that I know to be particularly dangerous from a knock you down & steal your wallet perspective but the roads and especially the choke points required by those famous rivers of cars I95 , Rte 29 and the BW Parkway could make it a scary ride.