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.
|Completed. A report summarizing the Phase 1 proof-of-concept work on all four projects is available on the following page.
SCOPE OF WORK
For SHRP 2 Project S08D
Analysis of the SHRP 2 Naturalistic Driving Study Data
SCOPE OF WORK
The objective of this project is 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 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 alternate approaches. 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.
Data file preparation and user support
The Virginia Tech Transportation Institute (VTTI) will provide 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, will provide roadway data files and support. Funds for VTTI and CTRE data file preparation and support will be provided separately .
VTTI will produce de-identified summary data sets, such as trip and event files, that will be available to all S08 contractors. During Phase 1, VTTI will work 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.
Data access, security, confidentiality, and IRB requirements
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.
PHASE 1: PRELIMINARY PROOF-OF-CONCEPT ANALYSIS
Task 1-1: Institutional Review Board Approval; Data Sharing Agreement.
Each S08 contractor will be responsible for complying with all legal requirements in connection with the research to be undertaken under the S08 Contract, including without limitation all applicable Department of Health and Human Services (DHHS) policies and regulations on the protection of human research subjects (45 CFR Part 46, as amended). Each contractor shall have an approved Federal Wide Assurance on file with DHHS and shall conduct the research in accordance with an IRB-approved protocol. Without limitation of the following, each contractor shall be responsible for ensuring initial and continuing review by the contractor’s IRB or another qualified IRB pursuant to an arrangement for cooperative research under 45 CFR Section 46.114, which shall be subject to approval by the National Academy of Sciences (NAS) IRB. Each contractor shall be responsible for maintaining the confidentiality of all research data in conformance with the approved research protocols, informed consent forms, and data sharing agreement.
Each S08 contractor shall cooperate with the NAS and the VTTI IRBs and shall comply with any requirements or conditions imposed on the research by these IRBs, including all conditions specified in the participant consent forms and a data sharing agreement which will be required for this project. Access to SHRP 2 NDS data is contingent upon IRB approval and execution of the data sharing agreement. The Data Access Guide contains the informed consent form for primary drivers in the SHRP 2 NDS and a sample data sharing agreement for use of the SHRP 2 NDS data.
Continuation of funding under this contract will be contingent upon NAS IRB approval. NAS reserves the right to terminate any S08 contract where IRB approvals are not obtained in a timely manner. Respondents to this RFP shall demonstrate: (1) the current status of its Federal Wide Assurance on file with DHHS; (2) training in the conduct of human subjects research provided to key staff members; (3) the organization’s IRB approval process; and (4) an understanding of issues regarding the protection of participant privacy consistent with the specific terms of the participant consent form and data sharing agreement.
Products: All necessary IRB approvals and executed data sharing agreement.
Task 1-2: Prepare detailed analysis plan, define and obtain initial access to data sets.
Immediately upon award, S08 contractors will develop a complete Phase 1 analysis plan and schedule of activities. They will work with VTTI and CTRE to define and obtain initial access to the SHRP 2 NDS data sets needed for these analyses. They will begin initial analyses to test their data file definitions and structure and their analysis plans on sample datasets. They will submit their complete Phase 1 analysis plans to SHRP 2 for review and approval.
The S08 projects are likely to share and provide input on some common data needs such as triggers for various events (near collisions, other collision surrogates, traffic events such as left turns, and other useful identifiers), data file structures, and machine vision software to generate new information (e.g., recognize speed limit signs or detect angry drivers from the face video). Where appropriate, we wish to establish common definitions and implementation methods for S08 contractors. There will be an initial one-day kickoff meeting of all S08 contractors scheduled as soon as feasible at VTTI in Blacksburg, VA to initiate this dialogue.
Products: Detailed analysis plan, defined data sets
Task 1-3: Present analysis plan at July 2011 SHRP 2 Safety Symposium
S08 contractors will present their analysis plans, in as much detail as is known at the time, at the SHRP 2 Safety Symposium in Washington DC on July 14-15, 2011.
Product: PowerPoint and/or other presentation and hand-out materials
Task 1-4: Access data, test analysis methodology, conduct preliminary proof-of-concept analyses, iterate as needed.
After their analysis plans are approved, contractors will test their analysis methodology on the SHRP 2 NDS data sets obtained in Task 1-2. As needed, they will revise their analysis plans and data needs, obtain additional data sets, access these data sets, and test again. Several iterations may be needed as contractors become familiar with the SHRP 2 NDS data, as they test various options for their data extraction and analysis, and as more data are available for analysis. The contractors’ Phase 1 analyses must confirm the viability of their analysis plans and must provide a basis for estimating the cost of their Phase 2 work, including preparation of all necessary datasets.
Products: Contained in Phase 1 interim and final reports.
Task 1-5: Phase 1 interim report
Contractors will prepare a brief interim report on work through early December 2011. The report should document the contractor’s progress in refining the analysis plan, obtaining the data, and applying the contractor’s statistical methodologies to the data. It is not intended for publication. The report should include:
- The analysis plan and methodology, with all modifications, including
- the data used and how they were extracted from the SHRP 2 NDS data files;
- how any crash surrogates were defined and used;
- the statistical or analytical methods used;
- how the results generalize to the target population
- Lessons learned about the use of the SHRP 2 NDS data sets, including accessibility, usability, IRB experience/requirements, and any other areas in which the use of the database might be improved.
- Any indications of results that may be obtained from analyses of the full data set and potential implications of these results.
Task 1-6: Phase 1 final report
Contractors will prepare a Phase 1 report documenting their results from Phase 1 and their plans for Phase 2. The report will include thorough discussions of the following:
- The priority area addressed and the specific research question or questions studied.
- Literature review of current knowledge on these research questions.
- The final Phase 1 analysis plan and methodology, including
- the data used and how they were extracted from the full SHRP 2 NDS data files;
- how any crash surrogates were defined and used;
- the statistical or analytical methods used;
- how the results generalize to address a significant highway safety problem.
- The results and their implications: what has been learned from the Phase 1 analyses and how these results can be applied to reduce crash and injury risk.
- Lessons learned about the use of the SHRP 2 NDS data sets, including accessibility, usability, IRB experience and requirements, and any other areas in which the use of the database might be improved.
It is recognized that the Phase 1 analyses will be able to address only a small portion of the SHRP 2 NDS data so that definitive results and implications may not be available after Phase 1.
Next, the Phase 1 report will provide a detailed plan for Phase 2, including thorough discussions of the following:
- Any revisions to the analysis plan and data file specifications proposed for Phase 2
- Potential amendments for IRB materials and data sharing agreement, if necessary
- Budget for the contractor’s Phase 2 activities. The Phase 2 budget should include funds for travel to SHRP 2 Safety Symposia in 2012 and 2013 and one additional meeting each year. As discussed above, it should not include costs for data file preparation and support activities from VTTI and CTRE.
- A separate budget for VTTIs and CTRE data file preparation and support activities for the contractor’s Phase 2 analyses, prepared in consultation with VTTI and CTRE. Funding for VTTI and CTRE data support in Phase 2 will be provided directly by SHRP 2 to VTTI and CTRE under separate contracts for each Phase 2 analysis contractor. Each S08 Phase 1 contractor must provide a budget for these VTTI and CTRE data file preparation and support activities.
- Anticipated results: how the Phase 2 analyses are expected to confirm, extend, or add to the Phase 1 results and how these final results can be applied to reduce crash and injury risk.
Phase 1 deliverables:
- Monthly and quarterly progress reports.
- Amplified work plan: two weeks after award. This should include any required modifications to the proposal and a schedule of major activities for the remainder of Phase 1.
- Detailed Phase 1 analysis plan and data set definitions: eight weeks after award.
- Research plan presentation at the SHRP 2 Safety Symposium in Washington DC on July 12-13, 2012.
- Phase 1 brief interim report: September 3, 2012.
- Phase 1 draft final report: December 31, 2012.
- Phase 1 final report: two weeks following receipt of comments on the draft report