Regarding the recent fatal crash in Brighton: I understand that the cyclist was traveling down a rather steep hill on an arterial, Commonwealth Avenue, at speed, ran a red light and collided with a vehicle that was crossing on the green. Last I heard, it was unknown whether the cyclist ran the light intentionally, or failed to notice it, or there was brake failure.
Here’s a Google Maps overhead view of the intersection.
The cyclist was coming from the lower middle of the image (may vary according to your screen size) in the service road, which is the rightmost road.
The cyclist’s view (more or less) approaching the intersection is shown in Google Street View.
There was a Boston Globe news story about the crash.
The Globe article makes a lot of the cyclist’s not wearing a helmet. That might indeed have prevented the fatality, but as we all know, a helmet is only a last resort. A very serious issue when traveling on the service road is conflict with vehicles turning right from the main roadway — this is right-hook central and not only for bicyclists. Note in the street view that a car is proceeding straight across in the service road, but there is a green light for the main roadway as well. You can move forward and back along the service road and main roadway too in the street view and verify that they have the same signal phase. There also doesn’t appear to be a prohibition against turning right on red, even from the main roadway. However, the location of the bicycle and bicyclist following the crash suggest that she collided with a vehicle traveling from right to left, where there would be sight-line issues due to the building on the corner. The article includes a quote from Pete Stidman, and I agree with what he said. One thing he suggested was special signals; a longer yellow might help, but only a separate signal phase for traffic turning right from the main roadway would eliminate the conflict.