How about getting rid of the freaking HOV lanes — the social experiment that reduces the road capacity between 20% and 33%, depending on the number of other lanes out there? Anyone who’s ever driven that side of the Beltway will tell you that the Inner Loop starts backing up into Virginia at almost precisely 3:30pm every day. Why? Because that’s when 1/3 of the I-270 spur lanes are taken away for HOV restrictions.
I believe that the problem is not the HOV on the Spur, but the number of people trying to shift lanes between the 270 split and Montrose RD. If you are trying to make the Montrose Road exit from the spur, you need to cross three lanes while traffic from the outer loop is trying to cross at least three lanes to get to the through lanes.
The next monster bottleneck is Northbound past Father Hurley where the road goes from three lanes to two. I have seen this pinch point back traffic up past 118.