Freepers, try this streaming video link (URL), you can get an excellent real time view of the police stopping and questioning drivers of white vehicles one by one on I-95 and the overall roadblock in the D.C. area:
http://nbc4.feedroom.com/start.jsp?&rf=bm&mp=WMP&wmp=1&rm=0&fr=091101_124434_4e8ac9xe8e1f56bfexw50ea&rdm=976788.5506014628
I'd checked NBC's FeedRoom a couple of times earlier this a.m. I believe it's just a clip, not live coverage.