Riskiest distraction for drivers = cellphones
I avoid speaking on my cellphone when I'm driving unless I'm on Hwy 280 between the Penninsula and San Francisco where people drive more carefully and leave a decent distance between cars. Glad I've been doing that since according to this Wall Street Journal story (subscription required)
Among the many distractions faced by car drivers, cellphones and other wireless devices contributed to far and away the most crashes, near-crashes and other incidents, according to a new government study expected to be released next week.
...The researchers also found drivers looked at the road ahead less while dialing manually (40% of time) than hands-free dialing (50%). That compares with 70% of time looking ahead in driving without talking on a cellphone. While talking, drivers became less aware of their surrounding situation -- instead looking straight ahead most of the time (90% of time for hand-held phones and 77% for hands-free phones, compared with 70% in normal driving).