Monitoring the Thursday A.M. commute: Outer loop snarled in Md., MARC delays MARC Camden Line trains are running on a single track between Riverdale and Greenbelt. Train 842 is expected to run 25 to 30 minutes late. A Red Line train heading for Glenmont is off-loading at White Flint, so some delays are possible. The outer loop of the Beltway remains slow in Maryland near Colesville Road due to the earlier accident. There's also serious congestion on the outer loop in Virginia near the Springfield Interchange. And we're hearing reports of Blue and Orange Line trains experiencing problems in downtown Washington, with trains reportedly holding or having other issues at Federal Center SW and Smithsonian. MARC Camden Line train 845 is running 10 minutes late and will board at the opposite track at Greenbelt, College Park and Riverdale. Southbound I-270 is very congested essentially from Germantown all the way down to the spur. Once you get near Rockville things slow down considerably, so expect delays if you're heading that way. The outer loop of the Beltway remains jammed up in Maryland after the earlier accident near Colesville Road. MARC Camden Line train 841 is terminating at the Greenbelt station due to the tree on the tracks. Riders are going to transfer onto train 843, which will run about 25 to 30 minutes late and make an additional stop at Riverdale. Expect crowding on train 843 due to the extra passengers. Train 840 to Baltimore will start out at the Riverdale station. The accident on the outer loop just after Colesville Road has been cleared from the shoulder. Again, heavy delays still remain approaching this spot. MARC Camden Line train 841 is stopped south of Greenbelt because a tree is down across both sets of tracks. Lanes have reopened on the outer loop of the Beltway after Colesville Road. The right shoulder remains blocked. Expect lingering delays approaching this area. The lovely weather continues with sun, light breezes and mild temperatures, according to the Capital Weather Gang. An accident on the outer loop just after Colesville Road is blocking the left three lanes. Delays are getting heavier and heavier. MARC train 843 won't have a working bathroom this morning due to a mechanical issue. No other MARC trains should have the same problem.