Comparison study of the prevalence of cell phone use while driving in the City of Victoria, British Columbia

Transcription

1 Final Report Comparison study of the prevalence of cell phone use while driving in the City of Victoria, British Columbia A final report on the research project surveying the number of drivers using a cell phone in Victoria, BC after the ban on cell phones went into effect in January April 30, 2010 Enquiries should be directed to: Glenyth Nasvadi ICBC Manager, Road Safety Planning and Research

2 1 Comparison study of the prevalence of cell phone use while driving in the City of Victoria, British Columbia Executive Summary A study conducted in 2009 looked at the prevalence of cell phone use while driving in Victoria, BC. This was an observational study of 8000 vehicles at 40 sites within the City of Victoria. The ban on driving with hand-held electronic devices went into effect in January The observational study was replicated in April 2010 to determine if there were any effects on driver habits after the ban was implemented. For this study, the definition of observation of cell phone use included visually observing the driver holding the cell phone to their ear while the vehicle was either in motion or stopped at a traffic light or stop sign. Texting, ing or use of any other handheld electronic device was not considered use of a cell phone for the purposes of this study. In the 2009 study, the mean percentage of drivers using cell phones in the study area was 4.41%. The outlying areas had a mean percentage of 4.48% compared to the downtown core s mean percentage of 4.13%. There were a total of 350 drivers observed using cell phones from the 8000 vehicles observed. In 2010, the mean percentage of drivers using cell phones in the study area was 0.94%. The outlying areas had a mean percentage of 0.90% compared to the downtown core s mean percentage of 1.0%. There were a total of 75 drivers observed using cell phones from the 8000 vehicles observed. Gender of the driver was noted and the ratio observed for both years remained relatively consistent with more male drivers observed using cell phones than female drivers. A comparison chart was created to display the differences in the number of cell phones counted at each site in 2009 and There was a significant decrease at all of the sites with the exception of one site that had the same count for both years. The range of number of cell phones observed in 2009 ranged from 2 to 15 while in 2010, the range was from 0 to 6 cell phones observed at each of the sites. The parameters of traffic density and road type did not reveal patterns of cell phone use within the study area. ArcGIS was used to create various maps which provided a visual analysis of the distribution of cell phone use at the data collection sites. A statistical summary of the data has been provided in the report.

3 Cell phone use while driving in Victoria, BC 2 1. Introduction In February 2009, students from the University of Victoria, Department of Geography, Thomas Edghill and Theresa Fingler conducted an observational study of the number of drivers using cell phones at 40 intersections within the City of Victoria, British Columbia. Previous studies have shown that the likelihood of being in a road accident increases significantly when cell phone use and driving are combined (Caird 2008). Such research has indicated that the use of a cell phone is one of the most prevalent causes for driver distraction. As a result, several Canadian provinces have implemented laws banning the use of cell phones while driving. Amendments to the Motor Vehicle Act of British Columbia came into effect January 1, Drivers can no longer use hand-held cell phones and other hand-held portable electronic devices (DriveSmartBC 2010). The observational study conducted in 2009 was conducted before any restrictions on cell phone use while driving were in place. The study was repeated in March/April of 2010 after the cell phone ban went into effect. A comparison of the 2009 and 2010 results has been provided in this final report along with an analysis of the correlation of cell phone use to traffic density and road type. 1.1 Study Objectives The goal of this study was to identify the prevalence of cell phone use at various locations within the City of Victoria, British Columbia and correlate this data with road type and traffic density. A comparison of the 2009 and 2010 results has been provided to determine if the ban on cell phone use has had an effect of driver habits. Using ESRI s ArcMap software, the data was utilized to create maps and a kernel density estimation surface. A Pearson s r statistical analysis was used to correlate percentage of cell phone use while driving and traffic density. 2. Study Area and Data Collection 2.1 Study Area The study area for the research is in the City of Victoria, British Columbia. Victoria is the largest urban area on Vancouver Island, and the 15th largest metropolitan area in Canada. The city has an area of 19.7 km 2 with a population of 83,250. The City of Victoria and surrounding area is known as the Capital Regional District (CRD) and has an area of km 2 with a population of 383,801. The CRD is made up of 13 municipalities and 3 electoral districts.

4 3 2.2 Data collection methods 2009 and 2010 Data was collected at 40 intersections within the City of Victoria (see table 1). The locations of the data collection sites were selected based on road type, either collector or arterial (see figure 1). Twenty intersections from each road classification were chosen as sites for data collection (see table 2 and 3). A systematic random sampling design to provide a regular spatially-distributed sample of intersections was selected to provide comprehensive results throughout the study area. A unique identification number, ranging from 1 to 40, was assigned to each of the data collection sites (see figure 1b). A stratified random sample subset of fifteen data collection sites were concentrated on intersections within the downtown core (see table 4). The boundaries of the downtown region consisted of the area south of Pandora Avenue, west of Cook Street, north of Humbolt Street and east of Wharf Street and the Johnson Street Bridge (see figure 2). Data collected at each site included the number of vehicles, number of drivers using a cell phone and passengers present in the vehicle, driver gender, time of observation and total minutes spent at each site (see figure 3). Handheld counters were used to track the number of vehicles passing the intersection and number of drivers using a cell phone at each intersection. There were 200 cars counted at each of the 40 sample sites for a total of 8000 cars. The survey targeted the drivers of passenger cars, trucks, minivans and sport utility vehicles. Emergency vehicles and taxis were not counted as part of the study. The 2009 observations were conducted on weekdays between February 12 19th, 2009 between the hours of 0830 and 1630 hrs. The 2010 observations were conducted on weekdays from March 29 April 2, 2010 and April 7, 2010 between the hours of 0830 and 1630 hrs. For consistency purposes, the time of the day for the data collection at each site in 2010 was chosen to correlate with a similar time of day that data was collected at each of the sites in 2009 (see table 5). All of the data collection site times in 2010 were conducted within 60 minutes of the corresponding data collection sites in For this study, the definition of observation of cell phone use included visually observing the driver holding the cell phone to their ear while the vehicle was either in motion or stopped at a traffic light or stop sign. Texting, ing or use of any other handheld electronic device such as an ipod Touch was not considered use of a cell phone for the purposes of this study. It was not possible to differentiate between a person dialling a cell phone and texting, so the act of dialling a cell phone was not included as part of the study. Although these activities are at present, not allowed under the Motor Vehicle Act, these parameters were set in the 2009 observational study and therefore, no changes to the data collection methods were adopted in 2010.

5 Cell phone use while driving in Victoria, BC 4 Direction of the traffic flow for purposes of observing vehicles was randomly chosen at each of the intersections. Location of the researchers at each of the intersections was chosen as either before or after the intersection. Number of lanes, ranging from 1 to 3, was noted in the observation field notes. At 34 of the sites, data collection was limited to one side of the road, observing traffic flow in only one direction. Six of the sites, (numbers 11, 15, 16, 17, 24, 36), were located in primarily residential areas. Traffic flow was considerably slower in these areas so all directions of traffic flow were observed at these six locations. The rate of traffic flow was adjusted according to the number of lanes observed. This calculation only affected the rate of traffic flow observed at each of these intersections. The sample size remained consistent at 200 vehicles for all of the intersections. Shapefiles for use with ArcMap were obtained from National Topographic Data Base (NTDB). The geographic coordinate system for these files was GCS_North_American_1983. The vector datasets including road network and water were used from the Mapsheet 092B06. The municipal boundary vector dataset (2006) was obtained from Statistics Canada. These shapefiles were obtained from 2006 files. All other datasets, such as cell phone data collection sites were derived from this basedata. 3. Methods 2010 data Selection of the data collection sites were based on their location according to road classification. The analysis of arterial road and collector road locations were included to determine if there were any trends regarding usage of cell phone based on the two road categories. Arterial roads are defined as a moderate or high-capacity road which is immediately below a highway level of service. An arterial road has the potential to carry large volumes of traffic between areas in urban centres. Collector roads are defined as low or moderate-capacity roads which are below a highway or arterial road level of service. Collector roads tend to lead traffic from local roads or sections of neighbourhoods to arterial roads or directly to highways (ICBC 2009). Twenty sites were selected from each of the road types. At intersections that had both an arterial road and collector road meeting, the direction of the traffic onto the selected road type determined the classification of the data collection point at that location. Statistical summaries of the datasets were formed from the results of the collected data. Two methods of analysis were made using ArcMap. A point pattern analysis was performed through the creation of a kernel density estimation (KDE) surface and a map was created to show the distribution of cell phone use throughout the study area. Pearson s r

6 5 statistical test was used to find a correlation between traffic rate per hour and percentage of cell phone use at a given intersection. A brief statistical summary of the cell phone count and percentage data for 2009 and 2010 is provided in table 6. The map showing the data collection sites with proportional symbology was created to show distribution of cell phone count throughout the study area (see figure 4). Data was displayed in 4 categories ranging from 0 to 6 cell phones observed. Pearson s r was calculated using Microsoft Excel software in order to find a correlation between the traffic rate per hour and cell phone counts per hour at each collection site. The Pearson s r method calculates the linear relationship between two variables with the output ranging from -1 to +1. A value nearing -1 indicates the existence of a negative linear relationship which consists of high values on the x-axis and low values on the y-axis. A value nearing +1 indicates the existence of a positive linear relationship which consists of low values on the x-axis and high values on the y-axis. A correlation of 0 indicates no correlation between the two variables (O Sullivan 2003). A KDE surface was created from the amalgamation of the traffic density calculated from the data gathered at each intersection. KDE methods are used to convert point data to continuous surfaces showing event density or intensity (Silverman 1986). The theory behind creating a KDE surface is to show a pattern of density at any location, not just the location where the event took place (O Sullivan 2003). This method was chosen to display the varying traffic rates per hour at the data collection points. KDE was done as a visual aid to identify areas of high density based on the known point data locations. The created surface should not be interpreted, in this case, to show the true value of events at unknown locations. The cell size of the KDE was 20m with a search radius of 550m. There were 7 categories of data classified using the natural breaks categorization. The point data for the cell phone counts were overlaid onto the traffic density KDE surface to provide a basis for visual analysis of the relationship between cell phone counts and traffic rates per hour (see figure 5). 4. Results study The mean percentage of drivers using cell phones in the study area was 4.41%. The outlying areas had a mean percentage of 4.48% compared to the downtown core s mean percentage of 4.13%. The percentage of drivers using cell phones on arterial roads was 3.88% and the percentage found on collector roads was 4.88%. The percentage range of cell phone counts ranged from 1.0% of drivers at the Cook and Johnson intersection to 7.5% of drivers at the Douglas and Finlayson intersection. Out of the 8000 drivers

7 Cell phone use while driving in Victoria, BC 6 observed, there were 350 drivers observed using a cell phone. The time spent at all of the collection sites combined was 854 minutes, a total of 14.2 hours of observation. The percentage of male and female drivers using a cell phone was 67.4% and 32.6% respectively. Of the 236 male drivers observed, the number of male drivers without passengers was 204 (86%), and the number of male drivers with passengers was 32 (14.0%). Of the 114 female drivers, there were 107 female drivers observed without passengers (94.0%) and 7 female drivers observed with a passenger (6%). The dataset provided by ICBC listed the 2007 proportion of the gender of licensed drivers as males 51% and females 49%. A summary of the 2009 data collection has been provided in table 7. The Pearson s r statistic calculated on the traffic rates per hour and the percentage of cell phone use had a correlation of with a p-value of This correlation is significant at the 95% confidence interval. This value showed that there was a weak positive linear correlation between the two variables of traffic density and percentage of cell phone use study The mean percentage of drivers using cell phones in the study area was 0.94%. The outlying areas had a mean percentage of 0.90% compared to the downtown core s mean percentage of 1.0%. The percentage of drivers using cell phones on arterial roads was 0.90% and the percentage found on collector roads was 0.98%. The percentage range of cell phone counts ranged from 0 to 3.0% of drivers at the data collection sites. Out of the 8000 drivers observed, there were 75 drivers observed using a cell phone. The time spent at all of the collection sites combined was 905 minutes, a total of 15.1 hours of observation. The percentage of male and female drivers using a cell phone was 76.0% and 24.0% respectively. Of the 57 male drivers observed, the number of male drivers without any passengers was 40 (70%), and the number of male drivers with passengers was 17 (30%). Of the 18 female drivers, there were 17 female drivers observed without passengers (94%) and 1 female drivers observed with a passenger (6%). The dataset provided by ICBC listed the 2007 proportion of the gender of licensed drivers as males 51% and females 49%. A summary of the 2010 data collection has been provided in table 8. The Pearson s r statistic calculated on the traffic rates per hour and the percentage of cell phone use had a correlation of with a p-value of This correlation is significant at the 95% confidence interval. This value showed that there was a weak positive linear correlation between the two variables of traffic density and percentage of cell phone use.

8 Observation notes 2010 The traffic pattern at the intersection of Catherine Street and Esquimalt Road changed from 2009 to In 2009, there were two lanes in the westbound direction. In 2010, this changed to one lane in the westbound direction. Minutes spent at this site increased to 46 minutes in 2010 from 23 minutes in All field observation sheets for 2010 have been provided for each of the sites. 4.3 Comparison charts A bar chart was created to show a visual comparison of the 2009 and 2010 results (see figure 6). All of the sites showed a decrease in the number of drivers using cell phones in 2010 with the exception of the Cook Street and Johnson Street intersection which had the same number of cell phone users observed. The intersection of Douglas Street and Finlayson Street had the highest number of cell phone users at 7.5% in 2009, and had the second highest number of cell phone users at 2.5% in the 2010 study. Histograms were created to show the distribution of the number of cell phone users observed at a given intersection in 2009 and 2010 (see figure 7). The most frequent value of cell phone users observed in 2009 was 9 instances of drivers using cell phones at 9 of the intersections. In 2010, the most frequent category was 1 driver observed at 13 of the intersections. There were 0 drivers using cell phones observed at 5 of the intersections in Discussion The methods used in the 2010 study were replicated as closely as possible to the methods used in the 2009 study. The primary difference in the data collection methods were the months in which the data was collected. The results obtained in 2009 were collected in February while the results collected in 2010 were in March/April. Location at the intersections in 2009 and 2010 were the same, as was the location of the researchers at each of the intersections. Time of day of the data collection was conducted at a similar time for both 2009 and 2010, however, the specific day of the week was not matched from the previous year. Thomas Edghill was not available to participate in the 2010 study. A student from the University of Victoria, Jennifer Elliot, assisted with data collection for All other parameters of the study remained the same. The results from the 2010 study showed a significant decline in the number of drivers using cell phones in the study area. There was a 78.57% drop in the number of cell phone users in the 2010 study after the cell phone use while driving ban went into effect on January 1, 2010.

9 Cell phone use while driving in Victoria, BC 8 In 2009, the number of drivers using cell phone ranged from 2 to 15 while in 2010, there were 0 to 6 drivers observed using cell phones at the collection sites. In addition to there being fewer drivers using cell phones observed, many drivers were seen to be using Bluetooth technology. There did not appear to be a notable geographic pattern of cell phone use throughout the study area in As found with the 2009 study, road type or traffic density did not appear to have an effect on driver cell phone use habits. The visual analysis results from does not suggest the distribution of cell phone use is based on any one or more factors studied. The subset of downtown Victoria sites does not reveal any patterns of cell phone use compared to the outlying areas. According to the demographic statistics collected, male drivers without passengers present were the most prevalent category of driver for both 2009 and The percentages of female drivers using cell phones with or without a passenger did not change from 2009 to The results from the 2010 study showed a consistent distribution of drivers using cell phones throughout the city. The results had a much smaller range of values compared to the 2009 results. Future research will provide additional datasets for the study that shows cell phone use in the area and driver habits. New research may reveal long term patterns in driver habits and will demonstrate whether the downward trend of cell phone use continues as was shown here with the 2010 results.

10 9 References Caird, J., Willness, Steel, Scialfa (2008). A meta-analysis of the effects of cell phones on driver performance. Accident Analysis and Prevention 40: Drive Smart BC (April, 2010). Cell Phone Amendment to Motor Vehicle Act. Retrieved from Insurance Corporation of British Columbia (2009). British Columbia Traffic Statistics. O Sullivan, D. & Unwin, D. (2003). Geographic Information Analysis. Wiley & Sons: New Jersey. Silverman, B. W. (1986). Density estimation for statistics and data analysis. Chapman and Hall, London.

11 Cell phone use while driving in Victoria, BC 10 Table 1. Listing of data collections sites with ID numbers. ID Location 1 Albany Street & Gorge Road East 2 Bay Street & Government Street 3 Bay Street & Shelbourne Street 4 Blanshard Street & Caledonia Avenue 5 Blanshard Street & Hillside Avenue 6 Blanshard Street & Johnson Street 7 Cook Street & Dallas Road 8 Cook Street & Fairfield Road 9 Cook Street & Fort Street 10 Cook Street & Johnston Street 11 Craigflower Road & Styles Street 12 Dallas Road & Douglas Street 13 Doncaster Drive & Hillside Avenue 14 Douglas Street & Fort Street 15 Douglas Street & Pandora Avenue 16 Douglas Street & Yates Street 17 Fort Street & Pandora Avenue 18 Fort Street & Richmond Road 19 Gorge Road East & Jutland Road 20 Hillside Avenue & Quadra Street 21 Bay Street & Cedar Hill Road 22 Blanshard Street & Fort Street 23 Catherine Street & Esquimalt Street 24 Cedar Hill Road & Hillside Avenue 25 Dallas Road & Huron Street 26 Douglas Street & Finlayson Street 27 Douglas Street & Topaz Avenue 28 Fairfield Road & Foul Bay Road 29 Fairfield Road & Moss Street 30 Fernwood Avenue & Pandora Avenue 31 Finlayson Street & Somerset Street 32 Government Street & Pandora Avenue 33 Government Street & Wharf Street 34 Government Street & Yates Street 35 Johnson Street Bridge 36 Menzies Street & Michigan Street 37 Pandora Avenue & Quadra Street 38 Quadra Street & Yates Street 39 Vancouver Street & Yates Street 40 Wharf Street & Yates Street

12 11 Table 2. Selected arterial road intersections in Victoria, BC. ID Location 1 Albany Street & Gorge Road East 3 Bay Street & Government Street 4 Bay Street & Shelbourne Street 5 Blanshard Street & Caledonia Avenue 7 Blanshard Street & Hillside Avenue 8 Blanshard Street & Johnson Street 11 Cook Street & Dallas Road 12 Cook Street & Fairfield Road 13 Cook Street & Fort Street 14 Cook Street & Johnston Street 15 Craigflower Road & Styles Street 16 Dallas Road & Douglas Street 18 Doncaster Drive & Hillside Avenue 20 Douglas Street & Fort Street 21 Douglas Street & Pandora Avenue 23 Douglas Street & Yates Street 28 Fort Street & Pandora Avenue 29 Fort Street & Richmond Road 30 Gorge Road East & Jutland Road 34 Hillside Avenue & Quadra Street

13 Cell phone use while driving in Victoria, BC 12 Table 3. Selected collector road intersections in Victoria, BC. ID Location 2 Bay Street & Cedar Hill Road 6 Blanshard Street & Fort Street 9 Catherine Street & Esquimalt Street 10 Cedar Hill Road & Hillside Avenue 17 Dallas Road & Huron Street 19 Douglas Street & Finlayson Street 22 Douglas Street & Topaz Avenue 24 Fairfield Road & Foul Bay Road 25 Fairfield Road & Moss Street 26 Fernwood Avenue & Pandora Avenue 27 Finlayson Street & Somerset Street 31 Government Street & Pandora Avenue 32 Government Street & Wharf Street 33 Government Street & Yates Street 35 Johnson Street Bridge 36 Menzies Street & Michigan Street 37 Pandora Avenue & Quadra Street 38 Quadra Street & Yates Street 39 Vancouver Street & Yates Street 40 Wharf Street & Yates Street

14 13 Table 4. Subset of sites in downtown core of Victoria, BC. ID Location 6 Blanshard Street & Fort Street 8 Blanshard Street & Johnson Street 13 Cook Street & Fort Street 14 Cook Street & Johnston Street 20 Douglas Street & Fort Street 21 Douglas Street & Pandora Avenue 23 Douglas Street & Yates Street 31 Government Street & Pandora Avenue 32 Government Street & Wharf Street 33 Government Street & Yates Street 35 Johnson Street Bridge 37 Pandora Avenue & Quadra Street 38 Quadra Street & Yates Street 39 Vancouver Street & Yates Street 40 Wharf Street & Yates Street

15 Cell phone use while driving in Victoria, BC 14

16 15 Table 6. Summary of selected results of cell phone data collection for 2009 and Based on a sample size of 200 cars at 40 sites for a total of 8000 cars observed. Location ID Location Sample 2009 Data Collection Results 2010 Data Collection Results Number of drivers using cell phones Percent Minutes at Site Number of drivers using cell phones Percent Minutes at Site 1 Albany & Gorge % % 22 2 Bay & Cedar Hill % % 25 3 Bay & Government % % 17 4 Bay & Shelbourne % % 17 5 Blanshard & Caledonia % % 9 6 Blanshard & Fort % % 21 7 Blanshard & Hillside % % 8 8 Blanshard & Johnson % % 13 9 Catherine & Esquimalt % % Cedar Hill & Hillside % % Cook & Dallas % % Cook & Fairfield % % Cook & Fort % % Cook & Johnston % % Craigflower & Styles % % Dallas & Douglas % % Dallas & Huron % % Doncaster & Hillside % % Douglas & Finlayson % % 9 20 Douglas & Fort % % Douglas & Pandora % % Douglas & Topaz % % Douglas & Yates % % Fairfield & Foul Bay % % Fairfield & Moss % % Fernwood & Pandora % % Finlayson & Somerset % % Fort & Pandora % % Fort & Richmond % % Gorge & Jutland % % Government & Pandora % % Government & Wharf % % Government & Yates % % Hillside & Quadra % % Johnson Street Bridge % % Menzies & Michigan % % Pandora & Quadra % % Quadra & Yates % % Vancouver & Yates % % Wharf & Yates % % 18

17 Table 7. Cell phone use while driving in Victoria, BC 16

18 Table 8. 17

19 Cell phone use while driving in Victoria, BC 18 Figure 1. Location of cell phone data collection sites in 2009 and 2010 in Victoria, BC.

20 Figure 1b. Data collection sites displaying site identification numbers. 19

21 Cell phone use while driving in Victoria, BC 20 Figure 2. Downtown subset of data collection sites in Victoria, BC with associated site identification numbers.

22 21 Figure 3. Sample of field data collection sheets Site Identification Number 35 Date Monday, March 29, 2010 Intersection Traffic direction Location at intersection Johnson Street Bridge Westbound After Number of Lanes 1 Start Time Finish Time Alone With Passenger Male Female

23 Cell phone use while driving in Victoria, BC 22 Figure 4. Data collection sites showing proportional symbols of cell phone counts in Victoria, BC, Based on a sample size of 200 cars at 40 sites for a total of 8000 cars observed.

24 Figure 5. KDE surface of traffic density with proportional symbols of cell phone counts at the collection sites in Victoria, BC, Darker blue areas indicate areas with higher traffic density. Based on a sample size of 200 cars at 40 sites for a total of 8000 cars observed. 23

25 Cell phone use while driving in Victoria, BC 24 Figure 6. Comparison of 2009 and 2010 results of number of drivers using cell phones in Victoria, BC. Based on a sample size of 200 cars at 40 sites for a total of 8000 cars observed. Albany & Gorge Bay & Cedar Hill Bay & Government Bay & Shelbourne Blanshard & Caledonia Blanshard & Fort Blanshard & Hillside Blanshard & Johnson Catherine & Esquimalt Cedar Hill & Hillside Cook & Dallas Cook & Fairfield Cook & Fort Cook & Johnston Craigflower & Styles Dallas & Douglas Dallas & Huron Doncaster & Hillside Douglas & Finlayson Douglas & Fort Douglas & Pandora Douglas & Topaz Douglas & Yates Fairfield & Foul Bay Fairfield & Moss Fernwood & Pandora Finlayson & Somerset Fort & Pandora Fort & Richmond Gorge & Jutland Government & Pandora Government & Wharf Government & Yates Hillside & Quadra Johnson Street Bridge Menzies & Michigan Pandora & Quadra Quadra & Yates Vancouver & Yates Wharf & Yates 2009 data 2010 data Number of drivers using cell phones

26 Number of intersections Number of intersections 25 Figure 7. Comparison of 2009 and 2010 results showing frequency of total number of cell phone users observed per intersection in Victoria, BC. Based on a sample size of 200 cars at 40 sites for a total of 8000 cars observed Distribution of number of cell phones observed per intersection 2009 Frequency Cell phones observed Distribution of number of cell phones observed per intersection Cell phones observed Frequency