The Governors Highway Safety Association released a study that sifted through 350 scientific papers dealing with distracted driving. They summarized their analysis in a nice report that can be downloaded here.
There are 4 types of distraction:
- Visual – looking at something other than the road
- Auditory – listening to something not related to driving
- Manual – manipulating something other than the steering wheel
- Cognitive – thinking about something other than driving
Smart phones provide all four modalities! About two thirds of drivers report using a cell phone while driving, and 7-10% were observed to be using one at any given time. About 12% of drivers admit to texting while driving, and about 1% of drivers are texting at any given time. At least one driver is reported to be distracted in 15-30% of car crashes.
The following items were gleaned from the papers reviewed:
- Cell phone use increases crash risk, but the exact amount is not known
- Hands-free cell phone use has not been shown to be safer
- Texting increases crash risk, but the exact amount is not known
- Hand-held phone bans reduce use somewhat
- Texting bans have not shown any significant effect, although high visibility enforcement campaigns offer some hope
Syracuse NY and Hartford CT enacted high visibility campaigns (“Phone in one hand, ticket in the other”) in late 2010 and spring 2011. They found that cell phone use dropped by half, and texting dropped 72% in Hartford and 32% in Syracuse. These results do not agree with the GHSA findings, most likely because of the intensity of the efforts in these two cities.
Bottom line: We all know that texting while driving is bad and cell phone discussions while on the road are not very good either. There may be some utility to enacting bans on these activities. However, given the other responsibilities of our police departments, enforcement will always be a lower priority. Engineering solutions like roadway rumble strips can help divert attention back to driving, and crash investigations should aggressively examine any contributions to driver distraction. Ultimately, we’re going to have to treat this problem like we do for driving while intoxicated, with stiff penalties and driving restrictions. Unfortunately, I don’t think we’ve got the fortitude to do it anytime soon.
Download: GHSA Report on Distracted Driving