Design Project 2
056:144 Human Factors
Submitted to: Professor Pennathur Submitted on: 09/22/12
Team All-Star

The purpose of this project is data collection of human behavior in a natural setting. This descriptive research is based on observation of real life situations, rather than a controlled research setting. The project involves monitoring drivers at traffic lights to determine the effect of cell phone use on braking behavior. These observations are analyzed to determine better considerations for human factors.

Procedure: In order to receive better observations and more usable samples of data, the group collected three samples from stoplight locations (intersections of Iowa and Madison, Burlington and Gilbert, and Clinton and College) all located in Iowa City, IA. The three samples were collected at different times of day, including morning (8-10 AM), midday (12-2 PM) and evening (4-6 PM). These times are assumed to include the most populated stoplight traffic, in order to provide more representative samples that can describe general behavior. Data was collected by group members at an individual stoplight location, in one direction (either East/West or North/South). Observation were recorded on provided data collection sheets each time the stoplight turned red (stop) for a 30 minute period. The variables collected included: The lane the vehicle was traveling in, whether a cell phone was being used while driving, the gender of the driver, the location in the lane based off stopping behavior, and the vehicle type. To record data, group members stood on either side of the street, at a stoplight location. Standing near the stoplight, group members logged data as vehicles moved through traffic. Variables were observed for a manageable amount of vehicles during each red (stop) light. During the period, basic observations were acknowledged as detailed in the results (below). A few vehicles were spot collected, as practice, before the data collection period began. Results: The analysis for this project is based off the compiled data and observations of group members. The compiled data includes 145 subjects or vehicles observed during 109 red (stop) lights at the various locations and times as seen in the Table 1.1 (below).

Table 1.1: Observed Results Stopping Behavior: | bumper behind the white line | | 92 | | | bumper over the white line | | 44 | | | passing through the red light | | 9 | Vehicle Type: | | 1-Car | | | 68 | | | 2-SUV | | | 21 | | | 3-Minivan | | | 15 | | | 4-Truck | | | 32 | | | 5-Other | | | 9 | Gender: | | 1-Male | | | 96 | | | 2-Female | | | 49 | Lane: | | 1-closest lane | | | 86 | | | 2-inner lane | | | 59 | Cell Phone: | | 0-no cell phone | | | 117 | | | 1-yes cell phone | | | 28 | | | Total red lights: 109 | | | Total: 145 | Recorded variable results for 145 total observed subjects/vehicles based off 109 red lights, results include samples from three stoplight locations (intersections of Iowa and Madison, Burlington and Gilbert, and Clinton and College) at different times of day.

The purpose of this project is data collection of human behavior in a natural setting. Monitoring drivers at traffic lights to determine the effect of cell phone use on braking behavior is the main comparison of this project. The distribution of braking behavior is illustrated in Figure 1.1 (below).

Figure 1.1: Distribution of stopping behavior

Subject's behaviors were recorded based off three behaviors upon stopping at the traffic light: bumper behind the white line, bumper over the white line, and passing through the red light illegally.

The results suggest many drivers (64%) follow proper driving procedures in an urban setting. Some drivers did cross over the white boundary line, 30% passed over, and 6% blew through the light entirely during observation. This is perhaps correlated to the size of the vehicle observed however, as many trucks, vans, and buses, were recorded. The traffic the intersection of Iowa and Madison in particular, was affected by many city and university buses and trucks. Most of the larger vehicles at this location passed over the white line. These vehicles are perhaps harder to control, for the driver, based off their size. The distribution of vehicles observed is illustrated in Figure 1.2 (below).

Figure 1.2: Distribution of vehicles observed

Vehicles observed included cars, SUV's, vans, trucks, buses, and others among those recorded at stoplight locations.

Cell phone use is a major problem for drivers. No accidents or problems were observed during the experiment; however the stopping behavior can be affected by cell phone use. Talking, calling, texting, and general use of cell phones was seen during observation. More disturbing observations included blatant use of cell phones during green lights, while turning, while on a moped, or even while passing through a red light illegally. Much of the cell phone was correlated to younger drivers in smaller vehicles. The stopping behavior affected by cell phone use is correlated and distributed among the three observation periods in Table 1.2 (below).

Table 1.2: Stopping behavior for drivers on a cell phone vs. not on a cell phone | | Morning | Midday | Afternoon | Total red lights:109 | | 25 | 33 | 41 | Cell Phone | Behind Line | 90% | 68.75% | 72.72% | | Over Line | 10% | 25% | 27.28% | | Run Light | 0% | 6.25% | 0% | | | | | | No Cell Phone | Behind Line | 68.63% | 65.23% | 68.77% | | Over Line | 31.37% | 23.90% | 25.58% | | Run Light | 0% | 10.87% | 4.65% |
Stopping behavior affected by cell phone use observed during the three high traffic periods.

Based off these results, there is little correlation to the cell phone use and stopping behavior. Both cell phone using and non cell phone using drivers stayed behind the white boundary line at least 60% of the time. Non cell phone users traveled over the line more frequently during observation. Morning drivers appear to be more alert, no drivers blatantly passed through a red light during that period. Also morning drivers using cell phones stopped behind the line in greater frequency than non cell phone using drivers. The cause of this may be the cell phone user's knowledge of their unsafe driving; purposefully driving more cautiously while using the cell phone. This would perhaps distribute more evenly with more observations, only 25 lights were observed for the morning period. The results have similar percentages among midday and afternoon drivers, morning drivers differed somewhat, with cell phone using drivers actually having better stopping behavior. This is perhaps due to the distribution of cell phone using and non cell phone using drivers seen in Table 1.3 (below).

Table 1.3: Distribution of drivers using cell phones | Morning | Midday | Afternoon | Using | 16.40% | 25.80% | 20.40% | Not Using | 83.60% | 74.20% | 79.60% |
Cell phone using drivers as observed during the three high traffic periods.

Morning drivers used cell phones less frequently than other observed periods. This distribution is somewhat startling to a safe driver, as cell phone use can be attributed many accidents, especially in a high traffic, urban area such as Iowa City. Among genders, there was little correlation to cell phone use as listed in Table 1.4 (below).

Table 1.4: Cell phone use among genders | Morning | Midday | Afternoon | Males | 40% | 75% | 27.30% | Females | 60% | 25% | 72.70% |
There was little correlation among genders using cell phone while driving.

Cell phone use among genders is balanced when compiled in total. These results may be skewed due to the distribution of males (66%) and females (34%) observed, however most of the cell phone users were observed in smaller vehicles. The results were analyzed to determine the effect of cell phone use on braking behavior. With the small sample of 145 drivers during 109 stoplights, there is little statistical significance to the data. However the practical significance of observations can draw important conclusions. Simple observation analysis is an effective way of determining better human factors for these complex real world situations.

Conclusion: Based off the results, there is little correlation of the effect of cell phone use on stopping behavior. The distribution of male and female cell phone using drivers is balanced when taking into account the three traffic periods. These results are not without observations however, the blatant use of cell phones while driving is a major problem correlated to millions of accidents across the U.S. Specifically here in Iowa City, the percentage of cell phone using drivers in problematic for thousands of pedestrians crossing streets, as well as the high volume "college town" traffic. The percentage of cell phone using drivers is cause for certain recommendations for safer driving. It is imperative to limit the cell phone use of drivers for safer traffic. Systems, with considerations for human factors, could improve traffic safety. The simplest solution is for drivers to put away their cell phones, leaving them in a place where they cannot be used. Most drivers know the implications of distracted driving, and yet they still use various technologies while driving without second thought. State legislation involving penalties would be a simplistic solution as it would encompass all Iowa drivers. Similar legislation in other states has given drivers more pause before using cell phone while driving. Other solutions include technologies in the car or on the cell phone itself. Various systems and applications can be installed to alert the driver of possible hazards of distracted driving. The data is limited in its statistical significance, with the small sample of 145 drivers during 109 stoplights. The practical significance of observations provides much better findings for this study, as compared to a laboratory setting. Laboratory analysis does not include the vast complexities of this real world situation. Observational analysis is much more useful for determining real world results, providing better recommendations for human factors.
Data from Excel: Number | Red Light | Date | Time | Location | Lane | Cell Phone | Gender | Stop Behavior | Vehicle Type | 1 | 1 | 9/18/2012 | 9:30 | Iowa and Madison | 2 | 0 | 1 | 1 | 4 | 2 | | 9/18/2012 | 9:30 | Iowa and Madison | 1 | 0 | 2 | 1 | 1 | 3 | | 9/18/2012 | 9:30 | Iowa and Madison | 2 | 0 | 1 | 2 | 4 | 4 | 2 | 9/18/2012 | 9:32 | Iowa and Madison | 1 | 0 | 1 | 2 | 5 | 5 | 3 | 9/18/2012 | 9:33 | Iowa and Madison | 2 | 0 | 1 | 1 | 4 | 6 | 4 | 9/18/2012 | 9:34 | Iowa and Madison | 1 | 0 | 1 | 2 | 4 | 7 | | 9/18/2012 | 9:34 | Iowa and Madison | 2 | 0 | 2 | 2 | 1 | 8 | | 9/18/2012 | 9:34 | Iowa and Madison | 1 | 0 | 2 | 1 | 1 | 9 | 5 | 9/18/2012 | 9:35 | Iowa and Madison | 2 | 0 | 1 | 1 | 4 | 10 | | 9/18/2012 | 9:35 | Iowa and Madison | 2 | 1 | 2 | 1 | 4 | 11 | | 9/18/2012 | 9:35 | Iowa and Madison | 1 | 0 | 1 | 1 | 4 | 12 | 6 | 9/18/2012 | 9:36 | Iowa and Madison | 1 | 0 | 2 | 1 | 2 | 13 | | 9/18/2012 | 9:36 | Iowa and Madison | 1 | 0 | 1 | 1 | 1 | 14 | | 9/18/2012 | 9:36 | Iowa and Madison | 1 | 0 | 1 | 1 | 1 | 15 | 7 | 9/18/2012 | 9:38 | Iowa and Madison | 1 | 0 | 2 | 1 | 1 | 16 | 8 | 9/18/2012 | 9:39 | Iowa and Madison | 1 | 0 | 1 | 1 | 4 | 17 | 9 | 9/18/2012 | 9:41 | Iowa and Madison | 1 | 0 | 1 | 1 | 2 | 18 | | 9/18/2012 | 9:41 | Iowa and Madison | 1 | 0 | 1 | 2 | 4 | 19 | | 9/18/2012 | 9:41 | Iowa and Madison | 1 | 0 | 1 | 2 | 1 | 20 | 10 | 9/18/2012 | 9:43 | Iowa and Madison | 2 | 0 | 1 | 1 | 1 | 21 | | 9/18/2012 | 9:43 | Iowa and Madison | 1 | 0 | 1 | 1 | 5 | 22 | 11 | 9/18/2012 | 9:44 | Iowa and Madison | 2 | 0 | 1 | 1 | 5 | 23 | 12 | 9/18/2012 | 9:45 | Iowa and Madison | 1 | 0 | 1 | 2 | 5 | 24 | | 9/18/2012 | 9:45 | Iowa and Madison | 1 | 0 | 1 | 2 | 4 | 25 | | 9/18/2012 | 9:45 | Iowa and Madison | 2 | 1 | 1 | 1 | 4 | 26 | | 9/18/2012 | 9:45 | Iowa and Madison | 1 | 1 | 2 | 1 | 1 | 27 | 13 | 9/18/2012 | 9:46 | Iowa and Madison | 1 | 0 | 2 | 1 | 1 | 28 | | 9/18/2012 | 9:46 | Iowa and Madison | 2 | 0 | 1 | 2 | 5 | 29 | | 9/18/2012 | 9:46 | Iowa and Madison | 1 | 0 | 1 | 1 | 2 | 30 | | 9/18/2012 | 9:46 | Iowa and Madison | 2 | 0 | 2 | 1 | 1 | 31 | 14 | 9/18/2012 | 9:48 | Iowa and Madison | 2 | 1 | 1 | 1 | 4 | 32 | | 9/18/2012 | 9:48 | Iowa and Madison | 2 | 0 | 1 | 1 | 4 | 33 | | 9/18/2012 | 9:48 | Iowa and Madison | 1 | 0 | 1 | 1 | 2 | 34 | | 9/18/2012 | 9:48 | Iowa and Madison | 2 | 0 | 1 | 1 | 2 | 35 | 15 | 9/18/2012 | 9:50 | Iowa and Madison | 1 | 1 | 2 | 2 | 1 | 36 | | 9/18/2012 | 9:50 | Iowa and Madison | 1 | 0 | 1 | 1 | 1 | 37 | | 9/18/2012 | 9:50 | Iowa and Madison | 1 | 0 | 1 | 1 | 3 | 38 | | 9/18/2012 | 9:50 | Iowa and Madison | 1 | 1 | 1 | 1 | 3 | 39 | | 9/18/2012 | 9:50 | Iowa and Madison | 2 | 0 | 1 | 2 | 3 | 40 | 16 | 9/18/2012 | 9:51 | Iowa and Madison | 1 | 0 | 1 | 1 | 4 | 41 | | 9/18/2012 | 9:51 | Iowa and Madison | 2 | 0 | 2 | 1 | 2 | 42 | | 9/18/2012 | 9:51 | Iowa and Madison | 1 | 0 | 1 | 1 | 2 | 43 | 17 | 9/18/2012 | 9:52 | Iowa and Madison | 1 | 0 | 1 | 2 | 4 | 44 | | 9/18/2012 | 9:52 | Iowa and Madison | 2 | 0 | 1 | 1 | 4 | 45 | | 9/18/2012 | 9:52 | Iowa and Madison | 1 | 0 | 1 | 1 | 4 | 46 | 18 | 9/18/2012 | 9:53 | Iowa and Madison | 2 | 0 | 2 | 1 | 1 | 47 | | 9/18/2012 | 9:53 | Iowa and Madison | 2 | 0 | 2 | 1 | 1 | 48 | | 9/18/2012 | 9:53 | Iowa and Madison | 1 | 1 | 2 | 1 | 2 | 49 | 19 | 9/18/2012 | 9:55 | Iowa and Madison | 1 | 0 | 1 | 1 | 5 | 50 | | 9/18/2012 | 9:55 | Iowa and Madison | 1 | 0 | 1 | 2 | 1 | 51 | 20 | 9/18/2012 | 9:56 | Iowa and Madison | 2 | 0 | 1 | 1 | 3 | 52 | 21 | 9/18/2012 | 9:57 | Iowa and Madison | 1 | 0 | 1 | 2 | 1 | 53 | | 9/18/2012 | 9:57 | Iowa and Madison | 1 | 0 | 1 | 1 | 1 | 54 | | 9/18/2012 | 9:57 | Iowa and Madison | 2 | 1 | 2 | 1 | 1 | 55 | | 9/18/2012 | 9:57 | Iowa and Madison | 2 | 0 | 1 | 2 | 5 | 56 | 22 | 9/18/2012 | 9:58 | Iowa and Madison | 2 | 0 | 1 | 1 | 2 | 57 | 23 | 9/18/2012 | 9:59 | Iowa and Madison | 1 | 0 | 1 | 2 | 5 | 58 | | 9/18/2012 | 9:59 | Iowa and Madison | 2 | 0 | 1 | 2 | 5 | 59 | 24 | 9/18/2012 | 10:00 | Iowa and Madison | 2 | 1 | 1 | 1 | 1 | 60 | | 9/18/2012 | 10:00 | Iowa and Madison | 1 | 0 | 1 | 1 | 1 | 61 | 25 | 9/18/2012 | 10:01 | Iowa and Madison | 2 | 1 | 2 | 1 | 2 | 62 | 26 | | 1:30 | Burlington and Gilbert | 1 | 0 | 1 | 2 | 3 | 63 | 27 | | 1:31 | Burlington and Gilbert | 1 | 0 | 1 | 1 | 1 | 64 | 28 | | 1:33 | Burlington and Gilbert | 2 | 0 | 1 | 2 | 1 | 65 | 29 | | 1:34 | Burlington and Gilbert | 2 | 0 | 2 | 1 | 4 | 66 | 30 | | 1:35 | Burlington and Gilbert | 1 | 1 | 2 | 1 | 2 | 67 | 31 | | 1:36 | Burlington and Gilbert | 1 | 0 | 2 | 1 | 1 | 68 | 32 | | 1:37 | Burlington and Gilbert | 1 | 0 | 1 | 2 | 3 | 69 | 33 | | 1:39 | Burlington and Gilbert | 2 | 0 | 1 | 1 | 4 | 70 | 34 | | 1:41 | Burlington and Gilbert | 1 | 0 | 2 | 2 | 1 | 71 | 35 | | 1:43 | Burlington and Gilbert | 1 | 1 | 1 | 1 | 4 | 72 | 36 | | 1:45 | Burlington and Gilbert | 2 | 0 | 1 | 1 | 1 | 73 | 37 | | 1:46 | Burlington and Gilbert | 1 | 0 | 2 | 1 | 1 | 74 | 38 | | 1:47 | Burlington and Gilbert | 1 | 0 | 1 | 2 | 2 | 75 | 39 | | 1:49 | Burlington and Gilbert | 1 | 0 | 1 | 1 | 4 | 76 | 40 | | 1:52 | Burlington and Gilbert | 2 | 0 | 1 | 2 | 4 | 77 | 41 | | 1:54 | Burlington and Gilbert | 1 | 1 | 1 | 1 | 1 | 78 | 42 | | 1:56 | Burlington and Gilbert | 2 | 0 | 2 | 1 | 1 | 79 | 43 | | 1:57 | Burlington and Gilbert | 1 | 0 | 2 | 2 | 1 | 80 | 44 | | 1:58 | Burlington and Gilbert | 2 | 1 | 1 | 2 | 1 | 81 | 45 | | 1:59 | Burlington and Gilbert | 2 | 1 | 1 | 1 | 1 | 82 | 46 | | 2:00 | Burlington and Gilbert | 2 | 1 | 1 | 2 | 4 | 83 | 47 | | 1:30 | Gilbert & Burlington | 2 | 0 | 1 | 2 | 3 | 84 | 48 | | 1:31 | Gilbert & Burlington | 2 | 0 | 2 | 1 | 1 | 85 | 49 | | 1:33 | Gilbert & Burlington | 1 | 0 | 1 | 2 | 4 | 86 | 50 | | 1:34 | Gilbert & Burlington | 1 | 0 | 2 | 3 | 3 | 87 | 51 | | 1:35 | Gilbert & Burlington | 2 | 1 | 2 | 1 | 2 | 88 | 52 | | 1:36 | Gilbert & Burlington | 1 | 0 | 1 | 1 | 1 | 89 | 53 | | 1:38 | Gilbert & Burlington | 1 | 0 | 1 | 2 | 1 | 90 | 54 | | 1:40 | Gilbert & Burlington | 1 | 0 | 1 | 1 | 4 | 91 | 55 | | 1:42 | Gilbert & Burlington | 1 | 0 | 2 | 1 | 1 | 92 | 56 | | 1:43 | Gilbert & Burlington | 2 | 1 | 1 | 1 | 4 | 93 | 57 | | 1:44 | Gilbert & Burlington | 1 | 1 | 2 | 1 | 1 | 94 | 58 | | 1:46 | Gilbert & Burlington | 1 | 0 | 1 | 1 | 2 | 95 | 59 | | 1:47 | Gilbert & Burlington | 1 | 1 | 1 | 2 | 4 | 96 | 60 | | 1:49 | Gilbert & Burlington | 2 | 0 | 2 | 1 | 1 | 97 | 61 | | 1:51 | Gilbert & Burlington | 2 | 0 | 1 | 1 | 1 | 98 | 62 | | 1:53 | Gilbert & Burlington | 1 | 1 | 1 | 1 | 1 | 99 | 63 | | 1:54 | Gilbert & Burlington | 2 | 0 | 1 | 2 | 4 | 100 | 64 | | 1:55 | Gilbert & Burlington | 1 | 0 | 1 | 1 | 1 | 101 | 65 | | 1:56 | Gilbert & Burlington | 2 | 0 | 1 | 1 | 3 | 102 | 66 | | 1:58 | Gilbert & Burlington | 1 | 1 | 1 | 1 | 1 | 103 | 67 | | 2:00 | Gilbert & Burlington | 1 | 1 | 1 | 3 | 4 | 104 | 68 | | 13:31 | Clinton and College | 1 | 0 | 2 | 2 | 1 | 105 | 69 | | 13:33 | Clinton and College | 1 | 1 | 2 | 1 | 1 | 106 | 70 | | 13:34 | Clinton and College | 2 | 0 | 1 | 2 | 3 | 107 | 71 | | 13:35 | Clinton and College | 2 | 0 | 1 | 3 | 1 | 108 | 72 | | 13:36 | Clinton and College | 2 | 0 | 2 | 3 | 1 | 109 | 73 | | 13:37 | Clinton and College | 1 | 1 | 1 | 1 | 4 | 110 | 74 | | 13:38 | Clinton and College | 1 | 0 | 1 | 1 | 2 | 111 | 75 | | 13:39 | Clinton and College | 1 | 0 | 2 | 1 | 1 | 112 | 76 | | 13:40 | Clinton and College | 1 | 0 | 2 | 1 | 1 | 113 | 77 | | 13:41 | Clinton and College | 1 | 0 | 2 | 1 | 1 | 114 | 78 | | 13:42 | Clinton and College | 1 | 0 | 2 | 2 | 1 | 115 | 79 | | 13:43 | Clinton and College | 2 | 0 | 2 | 3 | 1 | 116 | 80 | | 13:44 | Clinton and College | 2 | 0 | 2 | 1 | 3 | 117 | 81 | | 13:45 | Clinton and College | 1 | 0 | 2 | 1 | 4 | 118 | 82 | | 13:46 | Clinton and College | 1 | 0 | 1 | 3 | 3 | 119 | 83 | | 13:47 | Clinton and College | 2 | 0 | 1 | 1 | 3 | 120 | 84 | | 13:48 | Clinton and College | 1 | 0 | 1 | 1 | 1 | 121 | 85 | | 13:49 | Clinton and College | 1 | 0 | 1 | 2 | 1 | 122 | 86 | | 13:50 | Clinton and College | 1 | 0 | 2 | 1 | 1 | 123 | 87 | | 13:51 | Clinton and College | 2 | 1 | 1 | 2 | 2 | 124 | 88 | | 13:52 | Clinton and College | 1 | 0 | 1 | 2 | 1 | 125 | 89 | | 17:00 | Iowa and Madison | 2 | 0 | 1 | 1 | 2 | 126 | 90 | | 17:01 | Iowa and Madison | 2 | 0 | 2 | 1 | 1 | 127 | 91 | | 17:02 | Iowa and Madison | 2 | 0 | 1 | 2 | 1 | 128 | 92 | | 17:03 | Iowa and Madison | 1 | 0 | 2 | 1 | 1 | 129 | 93 | | 17:04 | Iowa and Madison | 2 | 0 | 2 | 2 | 1 | 130 | 94 | | 17:05 | Iowa and Madison | 1 | 0 | 2 | 2 | 1 | 131 | 95 | | 17:06 | Iowa and Madison | 1 | 0 | 1 | 1 | 1 | 132 | 96 | | 17:07 | Iowa and Madison | 1 | 1 | 1 | 1 | 3 | 133 | 97 | | 17:08 | Iowa and Madison | 1 | 0 | 2 | 1 | 3 | 134 | 98 | | 17:09 | Iowa and Madison | 2 | 0 | 1 | 2 | 1 | 135 | 99 | | 17:10 | Iowa and Madison | 2 | 0 | 1 | 3 | 1 | 136 | 100 | | 17:11 | Iowa and Madison | 1 | 0 | 1 | 1 | 1 | 137 | 101 | | 17:12 | Iowa and Madison | 1 | 0 | 1 | 1 | 2 | 138 | 102 | | 17:13 | Iowa and Madison | 1 | 1 | 2 | 2 | 2 | 139 | 103 | | 17:14 | Iowa and Madison | 2 | 0 | 1 | 1 | 4 | 140 | 104 | | 17:15 | Iowa and Madison | 1 | 0 | 2 | 3 | 2 | 141 | 105 | | 17:16 | Iowa and Madison | 1 | 0 | 2 | 1 | 1 | 142 | 106 | | 17:17 | Iowa and Madison | 2 | 0 | 2 | 1 | 1 | 143 | 107 | | 17:18 | Iowa and Madison | 1 | 0 | 1 | 2 | 1 | 144 | 108 | | 17:19 | Iowa and Madison | 2 | 0 | 1 | 2 | 1 | 145 | 109 | | 17:20 | Iowa and Madison | 1 | 0 | 1 | 3 | 2 |