Its nothing to do with DSC. Its called having the capability for thought and judgement. When I was gingerly driving up the hill with kids around throwing snowballs, that was not a time to use the phone. While I was driving at 10mph along the wide, clear open road with not a soul in sight, that, unsurprisingly, was a relative safe time to use the phone. Of all the demands placed on a driver, trundling along at 10 while on the phone should not be the greatest of them! I could have shut my eyes and had a 99% chance of making it safe.