BACKGROUND
With the increased emphasis on highway safety, both nationally and with many local agencies, more individuals look to the Highway Safety Manual (HSM) for guidance on how to reduce fatalities and serious injuries on roadways. However, it may be challenging for new users of the crash prediction methods in HSM Part C to understand the various definitions, facility types, facility features, and input values used in safety performance functions (SPFs) and adjustment factors (AFs). This situation can lead to the improper application of the HSM predictive methods.
Research is needed to develop resources and ensure state department of transportation staff and other practitioners can interpret and apply the correct input values to crash prediction models to better support data-driven safety analysis.
OBJECTIVE
The objective of this project is to develop an imagery reference to assist practitioners in understanding the data elements and definitions used in crash prediction methods as outlined in Part C of the HSM, 2nd Edition.
The imagery reference will feature graphics, photographs, drawings, plots, multimedia, and other visual aids to clearly illustrate the characteristics and features of the inputs utilized in predictive analysis.
Accomplishment of the project objective will require at least the following tasks.
TASKS
The sequencing of tasks and deliverables, such as technical memorandums or summary reports, shall be structured for delivery in quarterly progress report submissions in which specific deliverables are requested or proposed. A time estimation for each phase is presented below. However, the proposer may re-sequence the timeline according to their best thinking.
PHASE I – PLANNING AND PREPARATION
Phase I is estimated to be accomplished within 9 months. The research team shall list the necessary inputs for all SPFs and AFs, including geometric design features, traffic control features, site characteristics, and other relevant factors, along with the corresponding proposed imagery references.
For each imagery reference, the research team shall:
- Specify the recommended image type (e.g., photograph, graphics, artistic rendering, multimedia, etc.), and
- Ensure the images accurately represent the elements defined in the HSM.
All images will be subject to multi-round review, revision, and approval by the NCHRP.
A sample section, including a draft annotated outline and a sample layout of the imagery reference, shall be provided. The sample layout shall include illustrations, diagrams, notations, and verification of consistency with the latest Model Inventory of Roadway Elements element descriptions published by the Federal Highway Administration.
Proposers shall clearly articulate their intended schedule of deliverables. The Phase I deliverables, at a minimum, shall include the following: (1) an amplified research plan, (2) a kick-off meeting with summary notes, (3) an annotated outline of the imagery reference, (4) a schedule for the deliverables and multitiered review of Phase II activities, and (5) a sample section of the imagery reference to demonstrate the document layout and ensure the inclusion of all the necessary information.
At the end of Phase I, the research team shall deliver Interim Report No. 1 and an updated Phase II research plan with a virtual interim meeting.
PHASE II – PRODUCT DEVELOPMENT
Phase II of the project, which will focus on developing the imagery reference based on the approved Interim Report No. 1, is estimated to be accomplished within 10 months (see Special Note B). Following the approved sample section, the research team shall develop the first draft imagery reference, including all visual content for NCHRP review and approval. This draft will include photographs, diagrams, and other graphics that clearly depict the facility types, features, and data inputs used in HSM crash prediction methods. To ensure clarity and alignment with HSM standards, the research team shall:
- Provide clear, concise captions for each visual, and reference the relevant HSM sections; and
- Adhere to the organizational structure of HSM Part C.
The research team shall also develop a plan to conduct a 2-hour virtual workshop in Phase III. A list of attendees, considering geographic and organizational diversity, must be prepared and will be reviewed and approved by the NCHRP.
At the end of Phase II, the research team shall deliver Interim Report No. 2, which includes a second draft imagery reference, a plan for the workshop, and an updated Phase III research plan.
PHASE III – WORKSHOP AND FINAL DELIVERABLES
Phase III shall not exceed 5 months and be reserved for conducting the virtual workshop and developing the final deliverables. The research team shall prepare a summary of the workshop activities, comments received, opportunities, challenges, barriers, and other observations learned from the workshop to refine the imagery reference.
Based on the feedback collected from the workshop, the research team shall revise the imagery reference. The final deliverables shall include:
- A final imagery reference,
- A conduct of research report with an executive summary documenting the entire project,
- A technical memorandum titled “Implementation of Research Findings and Products”, and
- A PowerPoint presentation with speaker notes that summarizes the project and distinctly illustrates for the audience how the research can be applied in their organization.
STATUS: Proposals have been received in response to the RFP. The project panel will meet to select a contractor to perform the work.
