A modest proposal: In line with recent comments regarding pedestrian crossing of 22nd (e.g. comparing it to a game of frogger) , I suggest we just stop enforcing traffic laws in the vicinity of these "dangerous" intersections and let nature take its course. The vast majority of accidents are caused by driver error (i.e. bad driving) and therefore allowing accidents to happen would get rid of drivers who make mistakes, improving safety for those who don't.

If you don't get the spirit of this, please google " a modest proposal" by Jonathon Swift.
On a more serious note, is there any evidence that making these particular intersections safer (i.e. adding interchanges) will reduce the number and/or severity of accidents? I ask this in all seriousness, because I suspect that just like building more freeways to relieve congestion, building safety features into roads, simply leads to to compensatory behaviour (i.e. unsafe driving) that will keep the accidents happening. This is just a hunch and I am perfectly willing to change it if presented with evidence to the contrary. Please note, I do not mean to downplay the importance of safety, or the feelings if anyone who has had an accident or knows someone who has.