26 July 2001: An estimated 3% of passenger vehicle drivers are talking on hand-held cellphones at any given time, according to a study by the US National Highway Traffic Safety Administration. The agency estimates that 500,000 people driving cars, vans, sport utility vehicles and pickup trucks are talking on cellphones at any given moment during weekday daylight hours.

The NHTSA observed more than 12,000 vehicles at 640 intersections during October and November. The research covered use of hand-held cellphones, not 'hands free' sets that allow drivers to keep both hands firmly on the wheel. Some 8% of the activity was by van and sport utility vehicle drivers during non-rush hour periods.

Female drivers were observed using cellphones more frequently than male drivers. This was especially true for female van and SUV drivers, where the cellphone use rate of 6.1 percent was nearly twice the rate for male drivers.

US Government data suggests some sort of driver distraction is a contributing factor in 20 percent to 30 percent of all crashes. There are no figures for how cellphones figure in crash causes.