This kind of traffic jams are pretty often in Moscow. The reason for them is often the top security measures that are needed by the governmental agencies to protect the important people while their ride. This time the jam got on the sat images in Russian analogue of google maps so it now can be seen from space too. Clicking on the image can reveal the map itself so that one can scale it or move up/down to see the real size of the jam.
It's interesting that the vip cars are not seen on those sat images. The reason for this that according to the same security regulations road should be closed far before the motorcade appears.
And inside there are some shots "from the ground".