I also did many miles commuting and riding in the city. A key, absolute rule after too many close calls was to never cross in front of a car about to enter or cross-over the road I was on unless I could see the driver looking at me. No matter how clear my right-of-way was or how obvious I thought I was. One close call about every 10K miles or so was enough for me to realize only purely defensive riding in the city would keep me uninjured (or worse). Sure a lot of riders rail at bad drivers, but that doesn't help in the end if you get t-boned. Hope this helmet helps with that.