Were your brake lights on when you lost the Volvo? Maybe it's not that helpful when stopped... (Heck, people rear-end FIRE TRUCKS with the whole array of lights going. It seems like this is a hole with no bottom...)I use L a lot of the time to take advantage of the regen, but I do get nervous about the lack of a brake light. I have had cars run up on me when I slow, and finally went back to D during a long stop & go session on the expressway after having a couple of guys behind were not paying attention. Maybe I'm overcautious, but I had a great Volvo totaled out by some jerk behind me who was playing with his radio and didn't notice that traffic had stopped.
Gen II Volts not only pay attention to the pedal but also the slowing rate, and turn on the brake lights when the rules call for it. I can't remember what it is in meters per sec^2, but it works out to about 0.1g. https://www.youtube.com/watch?v=_F4iyghT-qA