a bit of an aside
makes an interesting read.
I have noticed that it seems the compounds used for tar snakes vary from area to area and have universally become slipperier over the past few years. Hwy 14 out of Cedar City, UT, was incredibly slippery when I took it in May 13, and that was with relatively new Pirelli Scorpion Trails at proper inflation. It became better over the crest on 14, but my psyche was wounded by then and all sphincters were shut and I had a death grip on the grips. This road was taken probably at about low to mid 70s (degrees, not mph).
I guessed that the compounds used had changed, but the above article documents it and the wasteful and dangerous practice of using too much for the financial gain of the contractor.