 Minimizing Roadway Embankment Damage from FloodingAugust 3, 2016 TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 496: Minimizing Roadway Embankment Damage from Flooding documents the state-of-the-practice on how the transportation community is protecting roadways and mitigating damage from inundation and overtopping. This report highlights major issues and design components specific to roadway embankment damage from flooding. It documen...
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 Use of Reclaimed Asphalt Pavement and Recycled Asphalt Shingles in Asphalt MixturesSeptember 12, 2016 TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 495: Use of Reclaimed Asphalt Pavement and Recycled Asphalt Shingles in Asphalt Mixtures summarizes current practices for the use of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in the design, production, and construction of asphalt mixtures. It focuses on collecting information about the use, rather t...
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 Life-Cycle Cost Analysis for Management of Highway AssetsMay 11, 2016 TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 494: Life-Cycle Cost Analysis for Management of Highway Assets documents the state of the practice of life-cycle cost analysis (LCCA) and risk-based analysis into state highway agencies' asset management plans for pavements and bridges on the National Highway System. The objective of this project was to develop an inventory o...
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 Practices for High-Tension Cable BarriersMay 24, 2016 TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 493: Practices for High-Tension Cable Barriers reports on the current state of the practice for high-tension cable barriers (HTCB) used in the medians of access-controlled roadways in the United States. Information on high-tension cable barrier systems related to state agency specifications, special provisions, design standar...
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 Performance Specifications for Asphalt Mixtures June 20, 2016 TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 492: Performance Specifications for Asphalt Mixtures documents the performance tests used in conjunction with volumetric properties for mixtures. Performance tests are intended to extend service life by guiding material selection and proportions. The synthesis provides examples of engineering tools used in the development and...
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 Practice of Rumble Strips and Rumble StripesMay 20, 2016 TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 490: Practice of Rumble Strips and Rumble Stripes documents current practices used by states installing rumble strips and rumble stripes. The report details and explores variations in state highway agency practices in terms of design, criteria, and locations for installation, maintenance, perceived benefits, communication of ...
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 Extending Bridge Service Life Through Field Welded Repairs and Retrofits March 17, 2016 TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 489: Extending Bridge Service Life Through Field Welded Repairs and Retrofits documents practices associated with field welded repairs on existing steel bridges used by bridge owners. The information presented includes the extent to which field welding is performed on existing bridges, common types of field welded repairs and...
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 Roundabout Practices June 27, 2016 TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 488: Roundabout Practices summarizes roundabout policies, guidance, and practices within state departments of transportation (DOTs) as of 2015. The synthesis may be used as a reference for state agencies that are creating or updating their roundabout and intersection control policies.
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 Public Perception of Mileage-Based User FeesFebruary 24, 2016 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 487: Public Perception of Mileage-Based User Fees explores proposals to replace the current motor fuel tax with a road usage charge assessed on vehicle-miles traveled, often called a mileage-base user fee (MBUF). The report identifies and assesses various measures of public opinion on the MBUF concept.
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 State Practices for Local Road SafetyJanuary 23, 2016 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 486: State Practices for Local Road Safety explores state programs and practices that address local agency road safety. The report focuses on changes in local road safety programs since the legislation of Moving Ahead for Progress in the 21st Century (MAP-21), and the use of Engineering, Enforcement, Education and Emergency S...
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 Converting Paved Roads to Unpaved January 20, 2016 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 485: Converting Paved Roads to Unpaved explores how common and under what conditions paved roads are converted to unpaved. NCHRP Synthesis 485 found that the practice of converting paved roads to unpaved is relatively widespread; recent road conversion projects were identified in 27 states. These are primarily rural, low-volu...
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 Influence of Geotechnical Investigation and Subsurface Conditions on Claims, Change Orders, and OverrunsFebruary 9, 2016 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 484: Influence of Geotechnical Investigation and Subsurface Conditions on Claims, Change Orders, and Overruns documents the extent and type of claims, change orders, and cost overruns from subsurface conditions for state departments of transportation (DOTs). The report also identifies practices used by agencies to reduce such...
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 Training and Certification of Highway Maintenance WorkersJanuary 15, 2016 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 483: Training and Certification of Highway Maintenance Workers documents front-line maintenance worker training and certification practices for highway transportation agencies in the United States and Canada. The report includes the types of topics being addressed by training and certification programs, the delivery methods u...
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 Work Zone Speed ManagementOctober 22, 2015 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 482: Work Zone Speed Management documents the current state of practice for work zone speed management, including data, procedures, techniques, and technical issues related to observing and comparing work zone speeds.
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 Economic and Development Implications of Transportation DisinvestmentJuly 17, 2015 TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 480: Economic and Development Implications of Transportation Disinvestment examines methods available to estimate disinvestment effects on transportation system integrity within and across modes in urban areas, regionally, and in non-metro areas, and the use of those methods by transportation agencies. The report focuses on m...
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 Forecasting Transportation Revenue Sources: Survey of State PracticesMay 24, 2015 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 479: Forecasting Transportation Revenue Sources: Survey of State Practices documents current and proposed forecasting methodologies, as well as shortcomings of methods as reported by state departments of transportation (DOTs). The report also includes information about the types of revenue being forecasted, and how satisfied ...
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 Design and Load Testing of Large Diameter Open-Ended Driven PilesJuly 15, 2015 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 478: Design and Load Testing of Large Diameter Open-Ended Driven Piles documents information regarding the current state of practice with respect to the selection, use, design, construction, and quality control of large diameter open-ended driven piles for transportation structures. This report may provide agencies with infor...
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 Methods and Practices on Reduction and Elimination of Asphalt Mix Segregation June 8, 2015 TRB's National Cooperative Highway Research Program Synthesis 477: Methods and Practices on Reduction and Elimination of Asphalt Mix Segregation provides guidance on how to reduce or eliminate segregation during aggregate production, mix design, asphalt mix production, mix transport and transfer, and placement. The report also explores options for reducing or eliminating segregate, as well as c... |