Run-off-road (ROR) traffic crashes account for almost one-third of the deaths and serious injuries each year on U.S. highways. The effective design of roadsides, including the placement of roadside safety devices, can reduce the frequency and/or severity of these crashes but requires an understanding of the nature and frequency of roadside encroachments. Unfortunately, the best quality encroachment data currently available were collected in the 1960s and 1970s. The age of these datasets means they are likely no longer representative of the current vehicle fleet or highway conditions. Further, each of these datasets has significant limitations, including specific exclusion of heavy vehicles and motorcycles and a very limited range of traffic volumes (i.e., less than 20,000 vehicles per day); such limitations have fostered much debate over the value of findings from these studies.
Immense progress has taken place in both the development of new roadside safety devices and in the improvement of existing devices since the 1960s. Proper development, testing, and placement of these devices along the roadside, however, is required to maximize their effectiveness. The guidelines for development, testing, and placement of these devices rely heavily on roadside encroachment data across the range of traffic volumes and vehicle types.
There is a critical need to collect new roadside encroachment data to understand the frequency and nature of encroachments across the entire vehicle fleet. These data will guide refinement of current crash testing procedures in the Manual for Assessing Safety Hardware (MASH) and facilitate updates to the Roadside Design Guide (RDG) and potentially the Highway Safety Manual (HSM). Thus, this research is supported by the Technical Committee on Roadside Safety’s (TCRS) Strategic Plan.
The objectives of this research are to (1) develop a database of roadside encroachment characteristics for a variety of roadside conditions and roadway types and (2) analyze the database to evaluate (a) the effects of the characteristics on the nature and frequency of roadside encroachments, (b) the relationship between unreported and reported crashes, and (c) whether heavy vehicles, buses, and motorcycles encroach differently than passenger vehicles.
Development of the database should address the following roadside encroachment characteristics, at a minimum:
Rural v. urban;
Urban curbed v. uncurbed;
Various traffic volumes and speeds;
Horizontal and vertical alignments;
Number of lanes, lane width, and access density.
Further, the database development should address the following roadside encroachment outcomes, at a minimum: reported and unreported; intentional and unintentional; tracking v. non-tracking; runoff distance; vehicle trajectory; and crash severity.
Accomplishment of the project objectives will require the following tasks.
Task descriptions are intended to provide a framework for conducting the research. The NCHRP is seeking the insights of proposers on how best to achieve the research objectives. Proposers are expected to describe research plans that can realistically be accomplished within the constraints of available funds and contract time. Proposals must present the proposers’ current thinking in sufficient detail to demonstrate their understanding of the problem and the soundness of their approach to accomplishing the project objectives.
Task 1. Conduct a critical review of the literature to identify (a) existing and potential methods for the collection of roadside encroachment data, including electronic encroachment monitoring techniques and (b) currently available data that may be applicable to the research.
Task 2. Identify agencies willing to participate in this study through sharing their crash and road inventory databases, and allowing the research team to monitor encroachments. Identify data elements that are needed but not available in existing databases. Submit a technical memorandum that summarizes the findings of Task 1 and 2 for NCHRP review.
Task 3. Propose a Phase II work plan for collection and analysis of data on encroachments on representative roadway segments that can be used in conjunction with existing databases to achieve the project objectives. The plan shall include (a) a detailed cost estimate for the data collection and (b) an estimated size and scope of the proposed encroachment database.
Note: The database file type shall be compatible with commonly used software.
Task 4. Submit an interim report presenting the results of Phase I.
Note: The contractor shall meet with NCHRP within 1 month of submitting the Task 4 interim report to obtain approval to conduct Phase II.
Task 5. Execute the approved work plan to collect roadside encroachment data with the participation of the agencies identified in Task 2.
Task 6. In order to demonstrate the utility and robustness of the database, analyze the roadside encroachment data in accordance with the approved work plan to determine:
a. The effects of characteristics in the database on the nature and frequency of roadside encroachments.
b. The relationship of unreported to reported crashes for various roadside hazards and features.
c. Whether heavy vehicles, buses, and motorcycles encroach differently than passenger vehicles and should therefore be specifically addressed within the RDG (as requested by NTSB for buses and other heavy vehicles) and in the MASH crash testing procedures.
Task 7. Submit a final report that documents results; summarizes findings; draws conclusions; and identifies and informs any needed updates to the RDG, HSM, and MASH. An appendix to the report shall include electronic files of (a) the database and (b) all datasets collected in the project.
A. The proposal, including appendices, shall not exceed 35 single-spaced pages; the Research Plan, Item 4 of the proposal, shall not exceed 15 single-spaced pages, in 12-point font or larger.
B. For budgeting purposes, proposers should plan for 2 in-person meetings with NCHRP in Washington, DC or Irvine, CA.
C. Proposals should include a task-by-task breakdown of labor hours for each staff member as shown in Figure 4 in the brochure, "Information and Instructions for Preparing Proposals" (http://onlinepubs.trb.org/onlinepubs/crp/docs/ProposalPrep.pdf). Proposals also should include a breakdown of all costs (e.g., wages, indirect costs, travel, materials, and total) for each task using Figures 5 and 6 in the brochure. Please note that TRB Cooperative Research Program subawards (selected proposers are considered subawards to the National Academy of Sciences, the parent organization of TRB) must comply with 2 CFR 200 – Uniform Administrative Requirements, Cost Principles, and Audit Requirements for Federal Awards. These requirements include a provision that proposers without a "federally" Negotiated Indirect Costs Rate Agreement (NICRA) shall be subject to a maximum allowable indirect rate of 10% of Modified Total Direct Costs. Modified Total Direct Costs include all salaries and wages, applicable fringe benefits, materials and supplies, services, travel, and up to the first $25,000 of each lower-tier subaward and subcontract. Modified Total Direct Costs exclude equipment, capital expenditures, charges for patient care, rental costs, tuition remission, scholarships and fellowships, participant support costs and the portion of each lower-tier subaward and subcontract in excess of $25,000.
D. Item 5 in the proposal, "Qualifications of the Research Team," must include a section labeled "Disclosure." Information relevant to the NCHRP's need to ensure objectivity and to be aware of possible sources of significant financial or organizational conflict of interest in conducting the research must be presented in this section of the proposal. For example, under certain conditions, ownership of the proposing agency, other organizational relationships, or proprietary rights and interests could be perceived as jeopardizing an objective approach to the research effort, and proposers are asked to disclose any such circumstances and to explain how they will be accounted for in this study. If there are no issues related to objectivity, this should be stated.
E. Proposals are evaluated by the NCHRP staff and project panels consisting of individuals collectively very knowledgeable in the problem area. Selection of an agency is made by the project panel considering the following factors: (1) the proposer's demonstrated understanding of the problem; (2) the merit of the proposed research approach and experiment design; (3) the experience, qualifications, and objectivity of the research team in the same or closely related problem area; (4) the plan for ensuring application of results; (5) the proposer's plan for participation by Disadvantaged Business Enterprises--small firms owned and controlled by minorities or women; and (6) the adequacy of the facilities.
Note: The proposer's plan for participation by Disadvantaged Business Enterprises should be incorporated in Item 12 of the proposal.
F. Copyrights - All data, written materials, computer software, graphic and photographic images, and other information prepared under the contract and the copyrights therein shall be owned by the National Academies of Sciences, Engineering, and Medicine. The contractor and subcontractors will be able to publish this material for non-commercial purposes, for internal use, or to further academic research or studies with permission from TRB Cooperative Research Programs. The contractor and subcontractors will not be allowed to sell the project material without prior approval by the National Academies of Sciences, Engineering, and Medicine. By signing a contract with the National Academy of Sciences, contractors accept legal responsibility for any copyright infringement that may exist in work done for TRB. Contractors are therefore responsible for obtaining all necessary permissions for use of copyrighted material in TRB's Cooperative Research Programs publications. For guidance on TRB's policies on using copyrighted material please consult Section 5.4, "Use of Copyrighted Material," in the Procedural Manual for Contractors.