BACKGROUND
NCHRP Web-Only Document 288: Standard Definitions for Common Types of Pavement Cracking proposed a set of discrete definitions for common cracking types in asphalt- and concrete-surfaced pavements. The definitions classify cracks based on information extracted from images collected by highway-speed data collection vehicles, including feature orientation, length, width, location, and other relevant factors. These definitions are intended to harmonize and facilitate comparable measurement and interpretation of pavement cracking across the highway community.
Research is needed to validate the proposed definitions and develop a practice in AASHTO format for their use by highway agencies.
OBJECTIVES
The objectives of this research are to (1) validate the proposed definitions developed in NCHRP Web-Only Document 288 for cracking in asphalt- and concrete-surfaced pavements, (2) suggest any needed refinements, adjustments, and/or additions to the , Standard Practice for Quantifying Cracks in Asphalt Pavement Surfaces from Collected Pavement Images Utilizing Automated Methods, in a format specified by the AASHTO Committee on Materials and Pavements.
In this research, the term “validate” encompasses the following aspects of the proposed definitions at a minimum:
· Their feasibility, i.e., can the defined procedures be accomplished with available state department of transportation (DOT) resources.
· The comparability of measurements generated using the proposed definitions, including their accuracy, precision, and resolution.
· Their utility, i.e., can the information support decisions DOTs must make at the network and project levels.
· Their sensitivity to the image characteristics.
· Their applicability to external data reporting requirements.
· Comparison of their measurements to ground referencing.
· Their comparison with traditional pavement cracking definitions.
· Size of their proposed grid, crack orientation, and width thresholds.
· Their identification or exclusion of potholes and other non-cracking features.
RESEARCH PLAN
Proposers are asked to provide a detailed research plan for accomplishing the project objectives and producing the deliverables required by each phase of the project. 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 issues and the soundness of their approach to meeting the objectives. The work proposed for each phase must be divided into tasks and proposers must describe the work proposed in each task in detail.
Deliverables shall include, at a minimum:
Phase I
1. A work plan to (a) validate the three levels of proposed cracking definitions developed in NCHRP Web-Only Document 288 on a wide array of pavement surfaces and textures in four to six states with highway systems of varying size in different climatic regions, geography, and functional class using digital image sets (that employ the format in AASHTO MP 47, File Format of Two-Dimensional and Three-Dimensional (2D/3D) Pavement Image Data, including metadata, if possible) from three or more different highway-speed data collection vehicles and associated fully or semi-automated crack detection and classification software, (b) measure the accuracy and sensitivity of the definitions to actual crack width and severity with a ground referencing procedure, and (c) determine the compatibility of the definitions with data collection equipment and crack detection and classification software. The work plan shall define the evaluation criteria for the validation effort.
2. An interim report that presents the proposed work plan and identifies (a) the participating state DOTs, (b) the proposed highway-speed data collection vehicles and associated fully or semi-automated crack detection and classification software, and (c) the proposed ground referencing procedure.
Phase II
1. A report presenting the results of the work plan approved in Phase I and their analyses and discussing (a) the validation of the proposed definitions, (b) the accuracy and sensitivity of the definitions to actual crack width and severity determined with the ground referencing procedures, (c) the compatibility of the definitions with data collection equipment and crack detection and classification software, and (d) their comparison with traditional definitions.
2. A technical memorandum describing the different ways, including pavement management systems, pavement design, and reporting, in which the three levels of proposed definitions can be used by state DOTs and any needed refinements, adjustments and/or additions to the definitions and the state DOT processes to make best use of the definitions.
3. A draft practice for verifying that automated and semi-automated equipment, software, and quality management practices meet the requirements of the proposed definitions, prepared in a format specified by the AASHTO Committee on Materials and Pavements.
4. Proposed refinements, adjustments and/or additions to the proposed definitions and in a format specified by the AASHTO Committee on Materials and Pavements.
5. A final report that documents results, summarizes findings, draws conclusions, and presents (a) in a format specified by the AASHTO Committee on Materials and Pavements. An appendix to the report shall include electronic files of all data obtained in the project and the results of the analyses conducted with the data.
STATUS: Proposals have been received in response to the RFP. The project panel will meet to select a contractor to perform the work.
