This final report describes the second Strategic Highway Research Program naturalistic driving study (SHRP 2 NDS) Safety Project S07 (In-Vehicle Driving Behaviour Field Study). The principal objective of the S07 project was to collect a comprehensive naturalistic driving database. This database–together with associated roadway, driver, and environmental data–provides a resource from which to study the role of driver performance and behaviour in traffic safety and how driver behaviour affects the risk of crashes. This involves understanding how the driver interacts with and adapts to the vehicle, the traffic environment, roadway characteristics, traffic control devices, and other environmental features. To accomplish its objective, the S07 project enrolled 3,247 volunteer drivers as primary participants, ages 16 to 98, across six sites: two counties surrounding Tampa, Florida; 11 counties in central Indiana containing Bloomington; one county in western New York containing Buffalo; four counties in North Carolina containing Raleigh, Durham, and Chapel Hill; 10 counties in central Pennsylvania containing State College; and three counties in Washington containing Seattle. The six study centers encompass more than 21,000 square miles, contain about 7.6 million registered vehicles of all types, and have a population of approximately 6.5 million people of driving age (>15 years). The six teams selected to manage the study centers were Indiana University (Indiana), CUBRC (New York), Westat (North Carolina), Battelle (Washington), Pennsylvania State University (Pennsylvania), and CUBRC/University of South Florida (Florida). These teams performed a variety of tasks at each study center, including establishing and maintaining appropriate Institutional Review Board (IRB) approvals, recruiting volunteer drivers to participate in the study, obtaining driver consent and performing driver assessments, installing the data acquisition system (DAS) in participant vehicles, managing the participants and fleet of equipped vehicles over the 38 months of data collection activities, and de-installing the DAS equipment. As described in the following sections, each of these tasks provided challenges that needed to be addressed for the data collection effort to be successful. Four of the six sites (Bloomington, Seattle, State College, and Tampa) used their local IRB for oversight. Of these four, all but Tampa were required to undergo a full IRB review. The remaining two sites (Buffalo and Durham) each had an initial full review by their local IRB before the start of the study but subsequently adopted Virginia Tech’s IRB as the “IRB of Record” during the execution of the study. Over the course of the study, 18 amendments to the original IRB application were prepared, submitted, and approved by the IRB committees overseeing the project. Recruiting participants for the NDS turned out to be the most challenging part of the study. The study design was intended to provide a balanced sample of drivers by age and gender. However, obtaining the desired number of participants in the specified age groups in a timely way proved to be more difficult than expected. Of most concern was the difficulty of attracting both younger (ages 16 to 20) and older (ages 76 and above) drivers. Recruiting activities formally began using the Center for Survey Research (CSR) at Virginia Polytechnic Institute and State University (Virginia Tech) as a single national call center for all study sites. After a few months, it became apparent that the national call center was not supplying sufficient participants. Thus, the study centers were directed to increase local recruiting to supplement the national call center efforts. The study centers employed a wide variety of recruiting methods, including fliers and posters, newspaper and magazine ads, TV/radio ads, websites, and social media. The success of the recruiting strategies varied from site to site. The most successful recruiting methods were TV and radio ads for three of the sites (Buffalo, Durham, and Seattle) and Craigslist for the other three sites (Bloomington, State College, and Tampa). In addition, the initial compensation levels for participation were raised in an effort to increase interest in participating in the program. It was necessary to obtain informed consent from potential participants before they could be enrolled in the study. In most cases, consent was obtained when the recruit showed up for assessment tests and equipment installation. The driver assessment tests, administered by a trained assessor, were an important source of information about the participants and complemented the naturalistic driving data. The objective of the assessment tests was to establish a baseline in functional abilities of the driver with regard to perception, cognition, and psychomotor and physical abilities. In addition, surveys or questionnaires included psychological testing and documentation of health, medical conditions, and medications as well as safe driving knowledge and history. Specific tests that were administered included a clock drawing test, Conners’ Continuous Performance Test, Optec 6500 Vision Testing (for acuity, day and night contrast sensitivity, colour perception, and peripheral vision), the Jamar Grip Strength test, and a Driving Health Inventory (DHI). Further details, including qualifications of the assessors and a list of tests in the DHI, can be found in the Chapter 3 section on participant assessment tests and surveys. Installation facilities were established at each of the six study centers. Study centers were required to provide one installation bay per 150 DAS units assigned to their site. Thus, the Buffalo, Seattle, and Tampa sites each established three installation bays, Durham established two installation bays, and State College and Bloomington each established one installation bay. The study centers also established the capability to perform two installations per day, per bay. As expected at the beginning of the program, installing the full set of DAS equipment in a vehicle almost always required less than 4 hours. During the course of the program, the actual number of installations completed per day ultimately depended on the success in recruiting participants in the required age groups and DAS equipment availability. Additional factors affecting the number of installations performed per day were the number of last-minute participant cancellations, participants failing to show up for their scheduled appointment (i.e., no-shows), and rejected vehicles. Participant management included answering questions about incentive payments, scheduling vehicle maintenance appointments, helping with questions from the participants’ garage mechanics should they arise during routine non-NDS maintenance, and servicing activities. Fleet maintenance activities included care and upkeep of the instrumentation in the participant’s vehicle, replacing a data drive that had reached its storage capacity, and repairing damaged NDS equipment. To assist in these activities, a Request Tracker (RT) tracking system was implemented by the Virginia Tech Transportation Institute (VTTI) to help monitor the fleet of installed vehicles and allow communication of any observed issues between VTTI and the study centers. This system proved to be quite effective in identifying and tracking issues of importance to the fleet. During the course of the program, VTTI issued more than 9,576 RT tickets to the six centers. These tickets covered issues such as vehicle maintenance, solid-state drive (SSD) replacements, and other operational issues. Another important activity was to conduct a crash investigation in the event that one of the participant vehicles was involved in a crash. There were three methods of notification when a participant of the driving study was involved in a crash. The fist and most common notification occurred when participants called the study center (or sent an e-mail) to indicate that they were in a crash, as per instructions in the consent agreement. The second was incidental notifications from participants, either when they spoke with research staff during scheduling of vehicle maintenance or when SSDs were swapped. Incidental notifications were usually associated with minor crashes, when the participant assumed it was not necessary to contact the study center. The third, and least common, was notification by VTTI. Based on the severity of the crash, one of two different levels of crash investigation was performed. Over the course of the study, 110 (Level 1 and Level 2) crash investigations were performed at the six study center sites. DAS de-installation activities during the NDS can be divided into the following two categories: de-installations that routinely occurred during the course of the program and de-installations of the participant fleet at the end of the program. The routine de-installations occurred when participants either completed their time in the study or left the study before their planned completion time (e.g., if moving). The end-of-program de-installation activities began at all study centers on September 1, 2013, and were completed in December 2013. In general, most of the de-installations were performed at the study center installation sites. However, some de-installations were performed in the field when necessary. Over the course of the study, under the direction of the National Academies, and with the support of VTTI, the teams at each of the six study centers successfully • Identified and contacted more than 16,358 people who expressed some interest in participating in the study. Of these, 3,247 became primary test participants in targeted demographic age and gender cells. This compares favourably with the goal of enrolling 3,100 to 3,300 participants which was established at the onset of the program. • Performed 3,362 installations of DAS equipment into approximately 35 different makes of participant vehicles. • Maintained and managed the fleet of participants and vehicles for approximately 38 months. • The study centers were aware of 188 crashes that were experienced by the instrumented vehicles in their fleets. None of these crashes involved a fatality or a severe injury. This is lower than the number of crashes that was expected at the beginning of the study and also lower than the number of crashes identified by VTTI. With regard to the latter point, the VTTI crash numbers are based, in part, on data obtained from the vehicles. It appears that there were crashes that were not reported by the participants to the study centers. The S07 program activities at the six study centers have contributed to the collection of a rich set of NDS data. Most of the instrumented vehicle data include information on vehicle speed, acceleration, and braking; all vehicle controls; lane position; forward radar (indicating headway distance to objects in front of the vehicle); and video views forward, to the rear, and on the driver’s face and hands. The study center instrumented vehicles travelled 49,657,037 miles during 6,650,519 trips, of which an estimated 5.4 million trips (81%) were made by consented drivers (based on driver ID) and are available to researchers. At the beginning of the program, a target of 3,900 DAS-years in the field was established. The six study centers obtained 3,958 participant years in the field, which is 101.5% of the goal. (Author/publisher) The Naturalistic Driving Study was tested in several locations with In-Vehicle Driving Behavior Field Studies, including: Bloomington, Indiana (S07A, http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3053), Central Pennsylvania (S07B, http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3054), Tampa Bay, Florida (S07C, http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3055), Erie County, New York (S07D, http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3056), Raleigh-Durham, North Carolina (S07E, http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3058), and Seattle, Washington (S07F, http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=3059)
Samenvatting