TRB's National Cooperative Highway Research Program (NCHRP) has released a pre-publication, non-edited version of Research Report 879: Optimal Replacement Cycles of Highway Operations Equipment. The report serves as a handbook on equipment replacement concepts and an instruction manual for making cost-effective replacement decisions. The research report presents a process for determining replac...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 875: Guidance for Evaluating the Safety Impacts of Intersection Sight Distance is a resource for practitioners involved in the planning, design, operations, and traffic safety management of stop-controlled intersections. It provides information on how to estimate the effect of intersection sight distance (ISD) on crash ...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 874: The Transportation Research Thesaurus: Capabilities and Enhancements documents the results of a comprehensive assessment of the Transportation Research Thesaurus’s (TRT’s) capabilities and strategies for the TRT’s future development. The TRT is a structured, controlled vocabulary of terms in English, used by TRB an...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 872: Contribution of Steel Casing to Single Shaft Foundation Structural Resistance proposes revisions to bridge design specifications based on comprehensive analytical and testing programs for investigating the effects of steel casing. Bridges are often constructed with a single enlarged shaft foundation supporting a co...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 871: Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction presents a proposed standard method for long-term laboratory aging of asphalt mixtures for performance testing. The method is intended for consideration as a replacement for the method in AASHTO R 30, “Mixture Conditioning of Hot Mix Asphalt...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 870: Field Performance of Corrugated Pipe Manufactured with Recycled Polyethylene Content explores the use of corrugated high density polyethylene (HDPE) pipe manufactured with recycled content and proposes guidelines for manufacturing these pipes to ensure they meet the service life requirements for the given appl...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 869: Estimating the Safety Effects of Work Zone Characteristics and Countermeasures: A Guidebook provides practitioners who develop phasing and staging plans for temporary traffic control through work zones with guidance to evaluate the safety impacts of their plan decisions. There is limited data on work zone crashes a...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 867: Keeping What You Paid For—Retaining Essential Consultant-Developed Knowledge Within DOTs presents guidance on the use of knowledge capture and active learning to ensure that essential, mission-critical knowledge is maintained within the agency when a contractor’s work is finished. Knowledge capture is the process o...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 865: Guidance for Development and Management of Sustainable Enterprise Information Portals provides guidance for the development and management of effective Enterprise Information Portals (EIPs) at state departments of transportation. EIPs have become key tools for transportation agencies as they make available informat...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 864: Seismic Evaluation of Bridge Columns with Energy Dissipating Mechanisms, Volume 1: Research Overview and Volume 2: Guidelines describes the evaluation of new materials and techniques for design and construction of novel bridge columns meant to improve seismic performance. These techniques include shape memory alloy...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 863: Material Properties of Cold In-Place Recycled and Full-Depth Reclamation Asphalt Concrete  presents procedures for determining material properties of cold-recycled asphalt mixtures for input to pavement structural design programs. Highway agencies are placing increasing emphasis on sustainability, recycling, a...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 862: Guide to Deploying Clean Truck Freight Strategies provides decision makers with a guide to assist in the potential deployment of fuel-efficient and low-emission truck freight strategies. The guide includes an analytical tool  and a user manual to identify and evaluate appropriate strategies that can be deploye...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 861: Best Practices in Rural Regional Mobility addresses the role of state transit program policies and regional planning agencies in the development of services that fall in the middle ground between intercity bus service and rural public transportation. This middle ground is defined as rural regional services. The rep...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 860: Assessing the Environmental Justice Effects of Toll Implementation or Rate Changes: Guidebook and Toolbox provides a set of tools to enable analysis and measurement of the impacts of toll pricing, toll payment, toll collection technology, and other aspects of toll implementation and rate changes on low-income and m...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 859: Consequences of Delayed Maintenance of Highway Assets presents a process for quantifying the consequences of delayed maintenance of highway assets that considers the asset preservation policy, the maintenance and budget needs, and the analyses of delayed maintenance scenarios. This process considers delayed mainten...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 857: Performance-Related Specifications for Pavement Preservation Treatments presents guidelines for use in preparing performance-related specifications (PRS) for pavement preservation treatments and, if desired, determining pay adjustment factors. Although PRS have been used for the construction of pavements, their use...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 856: Specifying and Measuring Asphalt Pavement Density to Ensure Pavement Performance examines the current state of knowledge and existing agency practices to measure and specify the in-place density of asphalt pavements. The report aims to guide agency decisions on selecting measurement methods and requirements for in-...

TRB's National Cooperative Highway Research Program (NCHRP) has released a pre-publication, non-edited version of Research Report 855: An Expanded Functional Classification System for Highways and Streets. This report builds upon preliminary engineering of a design project, including developing the purpose and need. In particular, it provides additional contexts beyond urban and rural, facilita...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 854: Guide for Identifying, Classifying, Evaluating, and Mitigating Truck Freight Bottlenecks provides transportation agencies state-of-the-practice information on truck freight bottlenecks using truck probe data rather than traditional travel demand models. The report embraces a broad definition of truck freight bottle...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 853: Guidance for Design Hydrology for Stream Restoration and Channel Stability provides written guidance and interactive tools to help hydraulic engineers assess the current conditions adjacent to a stream crossing and in the upstream watershed. Specifically, the guidance and tools provide support in assessing the curr...