Project snapshot. More details below.
Impact on Practice
|ANALYSIS OF DRIVING BEHAVIOR FIELD STUDY DATA AND COUNTER MEASURE IMPLICATIONS (S08A, S08B, S08C, S08D)
Analysis of early NDS data to address four high-priority topics: safety on rural two-lane curves, rear-end crashes, driver inattention, and offset left-turn lanes. Phase 1 demonstrated proof-of-concept; Phase 2 will conduct full analyses.
Results from these analysis projects will be used to design or refine cost-effective measures to reduce road departure crashes, warn inattentive drivers, and help DOTs design intersections that balance crash risk with construction and maintenance costs. Experience in analyzing the data will help establish efficient methods to identify, extract, and analyze NDS data that will benefit other data users.
|Three projects were approved for full analysis beginning in spring of 2013. A report summarizing the Phase 1 proof-of-concept work on all four projects is available on the following page.
Staff Responsibility: Kenneth Campbell
The project is divided into two phases. In Phase 1, the contractor will conduct preliminary proof-of-concept analyses using small datasets derived from data obtained in the first few months of SHRP 2 NDS data collection to develop, test, and validate the contractor’s analytic approach or to compare the feasibility of alternateapproaches. If a contractor’s work is chosen to move into Phase 2, the contractor will conduct full analyses, with any appropriate modifications based on their Phase 1 analyses, to make the most appropriate use of the full SHRP 2 NDS data set. Approval to conduct Phase 2 for each Phase 1 contractor will depend on satisfactory completion of Phase 1 and on other factors such as the potential usefulness of the contract’s Phase 2 results to improve safety and reduce crash risk, the contract’s Phase 2 budget, and the overall coverage of priority research areas across all contractors. It is possible that not all Phase 1 contracts will proceed to Phase 2.
The overall objective of this project was to conduct analyses of the SHRP 2 Naturalistic Driving Study (NDS) data to obtain new information and insights on critical safety issues. The results of these analyses should: lead to real-world applications and safety benefits – theoretical knowledge without potential applications is not a priority; be broadly applicable to a substantial number of drivers, roadways, and/or vehicles in the United States; demonstrate the use of the unique NDS data – similar results could not be obtained from existing non-naturalistic data sets.
The project is divided into two phases. In Phase 1, the contractor conducted preliminary proof-of-concept analyses using small datasets derived from data obtained in the first few months of SHRP 2 NDS data collection to develop, test, and validate the contractor’s analytic approach or to compare the feasibility of alternate approaches. If a contractor’s work is chosen to move into Phase 2, the contractor conducted full analyses, with any appropriate modifications based on their Phase 1 analyses, to make the most appropriate use of the full SHRP 2 NDS data set.
Approval to conduct Phase 2 for each Phase 1 contractor depended on satisfactory completion of Phase 1 and on other factors such as the potential usefulness of the contract’s Phase 2 results to improve safety and reduce crash risk, the contract’s Phase 2 budget, and the overall coverage of priority research areas across all contractors. It is possible that not all Phase 1 contracts proceeded to Phase 2.
The Virginia Tech Transportation Institute (VTTI) provided data files and user support for all S08 analysis contractors. The Iowa State University Center for Transportation Research and Education (CTRE), the Project S04A Roadway Information Database contractor, provided roadway data files and support. Funds for VTTI and CTRE data file preparation and support were provided separately .
VTTI produced de-identified summary data sets, such as trip and event files, that will be available to all S08 contractors. During Phase 1, VTTI worked with each S08 contractor under the direction of SHRP 2 staff to develop sampling and data processing procedures to implement, test, and refine each contractor’s analyses. Production of analysis data sets for each S08 contractor will be carried out by VTTI under the direction of the S08 contractors using algorithms provided by the S08 contractors. Several iterations may be needed as contractors become more familiar with the NDS data. Under the direction of SHRP 2 staff, VTTI also will work with each contractor to develop each contractor’s sampling and data processing procedures and technical support budget for their Phase 2 proposal.
Contractors should take data file preparation costs into consideration in developing their analytical methodologies. The final SHRP 2 NDS data set will be very large – approaching one petabyte. Data file preparation costs can be substantial to produce analysis files that have not been carefully thought out. No single Phase 2 S08 project can use a disproportionate part of the available VTTI and CTRE resources, which provide data file preparation and support for all S08 Phase 1 and Phase 2 analysis projects.
SHRP 2 NDS data are being collected in a research project involving human subjects. Therefore, use of the data is subject to federal regulations governing protection of human subjects. Requirements for data confidentiality and security will be strictly followed in all S08 contracts. Institutional Review Board (IRB) approval by the contractor’s home institution is likely to be required in most, if not all, S08 studies. A data sharing agreement will also be required.
During Phase 1, VTTI will work with each S08 contractor under the direction of SHRP 2 staff to establish procedures for accessing the SHRP 2 NDS data. De-identified data sets may be supplied to S08 researchers subject to the terms of a data access agreement which will be established under Task 1 of each project. Access to the most protected information such as driver face video will only be permitted at the VTTI secure data enclave. See the SHRP 2 Data Access Guide for additional detail.
A separate effort will collect roadway data on about 4,500 miles of roads in each site. A roadway data collection vehicle will drive selected roads and record roadway geometry (horizontal curvature information, grade, cross slope, lane and shoulder information), speed limit signs, and intersection locations and characteristics. Data will be obtained from the six study sites over a two-year period. The order in which the study sites will be collected has not been determined yet, but priority will be given to those sites that deployed DAS early in the study. The roadway data do not involve human subjects, so they should not raise confidentiality issues or require IRB approval for their use. As noted above, CTRE will provide roadway data files and support.
Project Status: This project is complete.
Product Availablity: The SHRP2 report
, Initial Analyses from the SHRP 2 Naturalistic Driving Study: Addressing Driver Performance and Behavior in Traffice Safety was published in June 2013. It is available as an Adobe PDF.