University of Illinois researchers have published a study in Transportation Research Part A: Policy and Practice that examines cellphone bans and accident rates using two unique factors: the length of observation time and the method used to measure driver density. Unlike most studies that focus on short-term results, this one used seven years’ worth of driver data in two neighboring states, one with a cellphone ban and one without. Also, the researchers examined the number of licensed drivers per mile of road, classified individual counties as urban, rural, or very rural, and analyzed trends in each class over time.
What’s the Big Idea?
For all three classes of counties, the implementation of a cellphone ban corresponded to an initial rise in accident rate, followed by a steep decline — but with differing magnitudes for each class. While there was a marked and sustained decrease in urban counties, very rural counties experienced a relative increase during the same period. The researchers admit they don’t know what’s behind this increase, but they believe that for urban areas, the persistent decline in accident rate over time is sufficient evidence for more cities to enact cellphone bans.