Policy-makers and planners must balance the benefits of operating freight automated vehicles (FAVs) with the additional burden they could place on state agencies and local jurisdictions. NCHRP Research Report 1028: State and Local Impacts of Automated Freight Transportation Systems , from TRB's National Cooperative Highway Research Program, details the impact of FAVs on state and local agencies and authorities. While the benefits of FAV operation are recognized, it is unclear how state and local agencies...

Roundabout implementation in the United States has increased in the last decade, and practitioners have learned lessons in successfully applying roundabouts in various land use and transportation environments and contexts. The TRB National Cooperative Highway Research Program's NCHRP Research Report 1043: Guide for Roundabouts provides information and guidance on all aspects of roundabouts. Supplemental to the report is NCHRP Web-Only Document 347: Background and Summary of a Guide for Roundabouts , whic...

Freeway congestion usually occurs at freeway merge, diverge, and weaving segments that have the potential to develop bottlenecks. To alleviate or mitigate the impacts of congestion at these segments, a number of active management operational strategies have been implemented such as ramp metering, hard shoulder running, managed lanes, and others. The TRB National Cooperative Highway Research Program's NCHRP Research Report 1038: Update of Highway Capacity Manual: Merge, Diverge, and Weaving Methodologies ...

Equipment failures often require state transportation agency fleet managers to consider whether the equipment should be repaired or replaced. The decision-making process typically considers a variety of factors. The TRB National Cooperative Highway Research Program's NCHRP Research Report 1046: Decision Making for Repair Versus Replacement of Highway Operations Equipment is a handbook to help determine the basis for decisions about what to do with a downed piece of equipment as well as a guide for formul...

Transportation agencies need to identify and evaluate current and emerging performance measures, analytic tools, and data sources in order to improve their ability to integrate issues such as climate change, goods movement, changing centers of population and economic activity, and telework into their decisions about system performance. NCHRP Research Report 1042: State Transportation Agency Decision-Making for System Performance: Practitioner’s Playbook , from TRB's National Cooperative Highway Research ...

As the Highway Safety Manual continues to evolve, determining the potential crash severity at a location becomes an increasingly vital component in predicting safety performance. NCHRP Research Report 1047: Development and Application of Crash Severity Models for Highway Safety: User Guidelines , from TRB's National Cooperative Highway Research Program, is designed to help predict crashes by injury severity on rural two-lane, two-way roadways, rural multi-lane highways, and urban and suburban arterials. ...

A more efficient and strategic approach is needed for managing transportation assets, in general, and, in particular, their foundational elements during their service life. This need is exacerbated by uncertainties in the impact of changes to the aging transportation infrastructure assets caused by continued degradation, climate change, unreliable funding, effects of international trade, and possible changes in national policies and priorities—all in the context of almost no information on the condition ...

Historically, the most common method for determining asphalt content was extraction using different methods and solvents such as trichloroethylene, methylene chloride, or n-propyl bromide. In the 1980s, the use of chlorinated solvents for asphalt extractions began to be questioned because of potential health and safety impacts and disposal difficulties. The pre-publication version of NCHRP Research Report 1060: Ignition Furnace Correction Factors: Identifying Influences and Minimizing Variability , from ...

Vegetated filter strips along highways, an accepted low-impact development best management practice (BMP), are a cost-effective alternative to hydraulically engineered BMPs. However, these treatments may be limited by site constraints (such as limited right-of-way and steep side slopes), and their effectiveness may vary depending on climate, soils, and other factors. The TRB National Cooperative Highway Research Program's NCHRP Research Report 1040: Achieving Highway Runoff Volume and Pollutant Reduction...

Bridges constructed with adjacent precast prestressed concrete box beams have been in service for many years and provide an economical solution for short and medium span bridges. A recurring problem is cracking in the longitudinal grouted joints between adjacent beams, resulting in reflective cracks forming in the asphalt wearing surface or concrete deck. The TRB National Cooperative Highway Research Program's NCHRP Research Report 1026: Guidelines for Adjacent Precast Concrete Box Beam Bridge Systems pr...