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5The objective of the SHRP 2 Safety focus area is to mitigate traf- fic injuries and fatalities by preventing, or reducing the severity, of collisions. To support that program effort, it was decided that a major aspect of the Safety area would be to conduct a large- scale naturalistic driving study (NDS) to address the role of driver performance and behavior in traffic safety. This involves understanding how the driver interacts with and adapts to the vehicle, the traffic environment, roadway characteristics, and other environmental features. Vehicle use was recorded con- tinuously in the SHRP 2 NDS. Information on vehicle travel or exposure can be extracted at the same level of detail as for safety-related events like crashes and near crashes. Hence, the SHRP 2 NDS is the first large-scale study to support detailed estimates of collision risk. Moreover, crashes are a leading cause of nonrecurring congestion. Collision prevention has added benefits in terms of reduced delay, fuel consumption, and emissions. For the exposure-based analysis approach supported by SHRP 2, characteristics of interest (such as roadway parame- ters) needed to be available for events, such as crashes, and for comparable driving segments where collisions did not occur. Due to the cost of mobile data collection, SHRP 2 was not able to collect roadway data using mobile data collection for all roads driven by participants in the Naturalistic Driving Study (NDS). Thus, it was anticipated that additional roadway data would come from existing sources in the public and private sectors. The goal of this research project was to design, build, and populate a Roadway Information Database (RID) with data from the mobile data collection project (S04B), existing road- way data (from public and private sources), and supplemen- tal data to help further characterize operations. The focus of this research was on providing good quality data that is linked to the NDS database and stored in a secure, flexible database, accessible using geographic information system (GIS) tools. The RID will in essence provide the road element for safety research for the more than 5 million trips taken by the NDS participants. The data will support a comprehensive safety assessment of how driver behavior and performance might be impacted by roadway characteristics, environmental and vehicular factors, and the influence of these factors and their interactions on collision risk, especially the risk of lane depar- ture and intersection collisions. The RID, through the use of dynamic segmentation, will enable safety researchers to look at data sets of selected road characteristics and study match- ing NDS trips to explore the relationships between driver, road, and vehicle. The six study sites where roadway data were collected are as follows: ⢠Bloomington, Indiana; ⢠Erie County, Buffalo, New York; ⢠RaleighâDurham, North Carolina; ⢠Tampa, Florida; ⢠State College, Pennsylvania; and ⢠Seattle, Washington. In order to accomplish this goal, the following objectives guided the development of the SHRP 2 RID: ⢠Assess user needs. ⢠Reevaluate mobile data collection vendors: 44 Develop short list to bid on request for proposals (RFP). 44 Determine vendor capabilities. ⢠Develop project specifications for data collection and delivery. ⢠Conduct pilot data collection and evaluation on initial 900 centerline miles (out of 12,500 total centerline miles) to refine processes and data accuracy requirements, while assuring that data were sufficient for safety analysis. ⢠Conduct data discovery for existing roadway and sup- plemental data from government, public, and private sources. C h a p t e r 1 Introduction
644 Developing basic long-term recommendations for data- base management after the SHRP 2 program. This report briefly explains the tasks completed by the project team to achieve these objectives. The report presents information on the identification of data requirements, the data collection plan, the data discovery and acquisition effort for existing roadway and supplemental data, the qual- ity assurance process on the mobile data collection project, the database design, database demonstration, and conclu- sions. Further details on project tasks are presented in the appendices. ⢠Develop a data collection strategy for roadway informa- tion that complements the SHRP 2 NDS data and supports exposure-based risk analysis, as well as other safety analyses. ⢠Provide coordination and quality assurance for the col- lection and delivery of data by the mobile data collection contractor. ⢠Acquire national basemap, existing roadway, and supple- mental data. ⢠Design, develop, and populate the SHRP 2 RID. ⢠Manage the RID for the duration of the SHRP 2 program, including the following: 44 Supporting data analysis efforts requiring roadway data.
