Totally apart from awareness and driving technique, the simple change of driving slower has a huge impact on safety.
The laws of physics dictate that going twice as fast equals four times the stopping distance, and should an impact occur, twice the speed equals four times the impart force.
Energy=1/2mass*velocity^2
"nearly half (46 per cent) of ... casualty crashes [above 40mph] probably would have been avoided, or reduced to non-casualty crashes, if none of the case vehicles had been traveling above the speed limit. A more conservative estimate, based on calculation of stopping distances and impact speeds, indicates that 29 per cent of crashes would have been avoided altogether"
Speed and Crash Risk - Executive Summary
“When travel speed increases by 1%, the injury crash rate increases by about 2%, the serious injury crash rate increases by about 3%, and the fatal crash rate increases by about 4%"
Traffic Safety Center Newsletter Winter 2008, Volume 5, No. 1: Traffic Safety Culture: the role of speed
I suspect this alone is more than enough to compensate for any increased risk from glancing at a Scangauge or coming up close to stop&go traffic from accordion driving.