Driver distraction has always been a focus of prevention among the traffic safety community. Driver distraction includes all activities that divert attention and full engagement from the task of driving including general inattention (lost in thought), smoking, eating, grooming, reading, interactions with passengers or vehicle controls, and electronic device use. Traffic safety researchers agree that driver distractions can greatly increase the risk that a crash will occur. American motorists appear to be highly conflicted about using cell phones while driving. Though most drivers (67.8 percent) surveyed in the 2014 AAA Foundation Traffic Safety Index reported that they supported restrictions on talking on a cell phone while driving; interestingly nearly 7 of 10 (69.2 percent) drivers in the same survey admitted to having talked on a cell phone while driving in the past month. Cell phones and other electronic communications or entertainment devices have been of particular interest to researchers. Two epidemiological studies, one in Canada and the other in Australia concluded that engaging in either handheld or hands-free cell phone conversations while driving leads to roughly a four-fold increase in the risk of crashing. Numerous simulator studies, closed-track, in-vehicle camera, and other studies have demonstrated significant increases in serious driving errors resulting from cell phone use while driving. In an ongoing series of studies, Dr. David Strayer, a professor of psychology at the University of Utah, has studied the nature of cell phone use while driving and has concluded that the distracting effects of cell phone conversation amount to a serious performance deficit. Strayer described this in a 2005 essay: “We found that even when drivers were directing their gaze at objects in the driving environment they often failed to see them because attention was directed elsewhere. Thus, talking on a cell phone created a form of inattention blindness, making drivers less aware of important information in the driving scene. We also compared hand-held and hands-free cell phones and found the impairments to driving are identical for these two modes of communication. There was no evidence that handsfree cell phones were any safer to use while driving than hand-held devices.” It is clear that conducting a cell phone conversation while driving leads to greatly weakened visual information-processing, with predictable and often disastrous consequences. Between 2011 and 2015, distracted driving was a factor in nearly 3 of every 10 traffic fatalities and more than 1 of every 5 serious injuries. Driver distraction ranks only behind driver impairment and driver speed as a prevalent driver behaviour in traffic fatalities and serious injuries. Until recently, Washington State had not attempted to measure the statewide level of driver distraction on Washington roads. This report documents the survey methods and results of Washington’s first statewide driver distraction observation survey. Intersections were sampled in incorporated areas 1) so that observers would be able to view more clearly the target behaviours of drivers inside their vehicles, and 2) so that observers would be able to collect a sufficient number of observations to reach a robust estimate. Accordingly, a database of all 6,279 intersections in Washington’s incorporated areas was generated and tagged with geographic coordinates, road names (where available), and other information. This process is detailed further in Appendix A. Intersections were randomly sampled from 23 counties with 50 or more total intersections. These 23 counties comprised 94 percent of all municipal intersections in the state (5,906 of 6,279). Each of the 23 counties was allotted the percentage of survey intersections equal to that county’s proportion of all intersections in the 23-county pool of 5,906 sites. For example, since 929 of the sites in the 23-county sample (15.7 percent) are in King County, 47 of the 300 sample sites (15.7 percent) were assigned to King County. The final sites were randomly selected for each county to reach the predetermined proportional allotment. In preparation for the survey, the survey coordinator assigned a smaller team to visit each site in order to document, photograph, and record relevant information. Geographic coordinates for each location were programmed into GPS devices and site sheets were produced to instruct the observers where to stand and which direction of travel to observe. Five two-person teams (consisting of an observer and a recorder) received classroom instruction and field training in observation and data recording procedures in April 2016. Data was collected using an iPad application modified from the Washington State seat belt observation application to collect distracted driver observations. The observations were conducted for 20 minute periods at each site in May 2016 between the hours of 7 a.m. and 6 p.m. For each vehicle surveyed at a given site, one member of the team observed oncoming vehicle motion and driver distraction behaviour and reported those observations verbally to the team’s recorder (facing the observer), who entered that information into the data fields appearing on the iPad screen. A more detailed description of the data collection process is described in Appendix B. A total of 22,322 vehicle drivers were observed in the survey. The weighted statewide estimate of Washington’s driver-distraction rate was 9.2 percent of all drivers observed, with a 95 percent confidence interval of +/- 0.89 percent; 5.6 percent of observed drivers were holding or manipulating phones, 1.3 percent were holding phones to their ears, and 2.3 percent were observed engaging in some other distracting behaviour, such as eating, tuning a radio, or attending to pets or children. (Author/publisher)
Samenvatting