CSX S364 collided with the rear of a Q116 on a restricted proceed signal at 31mph Tuesday morning. Miraculously there were no injuries, although three intermodal cars on the 116 were derailed. Until just a few months ago under Conrail/NORAC rules, the signal would have been a stop & proceed.
Perhaps if you were required to stop, and then proceed at Restricted Speed as opposed to just slowing down to Restricted Speed, the train may have been going just a bit slower and it's crew may have been able to comply with Restricted Speed which would mean they would be able to stop in half the range of vision.
I don't think that the "Restricted Proceed" signal is better than the Stop & Proceed.