TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 530: Construction and Rehabilitation of Concrete Pavements Under Traffic identifies practices from projects representing a wide range of conditions and techniques. The current state of the practice in constructing or rehabilitating concrete pavements under traffic relies primarily on a few high-profile and well-documented projects. Sixteen case examples were reported to illustrate successful projects conducted under a variety of scenar...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 523: Integration of Roadway Safety Data from State and Local Sources documents the ways in which transportation agencies are collaborating with local agencies to integrate and maintain data. This information can help inform how transportation agencies approach the challenge of facilitating access to and integrating data from a multitude of information systems from external sources. Accompanying the report are the following appendices: ...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 529: How Transportation Agencies Assess the Value of Added Capacity Highway Projects Versus Other Modal Projects and Strategies summarizes the methods and policies used by state departments of transportation (DOTs) and metropolitan planning organizations (MPOs) to evaluate and compare different types of transportation improvement strategies. This information will help to quantify the full spectrum of benefits, costs, and economic impac...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 518: Staffing for Alternative Contracting Methods documents current practices in state departments of transportation (DOTs) staffing and organizational structure for alternative contracting methods (ACMs). ACMs include design–build, construction manager/general contractor, public–private partnerships, and other innovative contracting techniques. ACMs shift more responsibility to industry for delivering and managing construction project...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 526: Inertial Profiler Certification for Evaluation of International Roughness Index determines the state of practice of certification of inertial profilers at the national and international levels. Inertial profilers are used to collect the repeatable and reproducible road profiles analyzed to calculate a smoothness or ride quality index, the most common of which—the International Roughness Index (IRI) — is a performance measure that ...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 524: Aggregate Quality Requirements for Pavements Aggregate Quality Requirements for Pavements documents transportation agency requirements for the quality of aggregates for various pavement types. Constructing and maintaining pavements requires an abundant and dependable supply of quality aggregates. Aggregate comes from a wide range of materials, including quarried rock, sand, and gravel, and materials such as slag, reclaimed asphalt...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 520: Integrated Transportation and Land Use Models presents information on how select agencies are using sketch planning models and advanced behavioral models to support decision making. The synthesis describes the performance of these models and the basic principles of land use/transport integration.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 517: Corrosion Prevention for Extending the Service Life of Steel Bridges documents and describes the current practice for corrosion prevention of steel bridges. This report provides information on choosing materials and coatings to prevent corrosion, and documents ways to develop an effective maintenance plan for newly constructed and in-service bridges and transportation structures. This report does not prescribe a practice or set of...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 525: Practices in One-Lane Traffic Control on a Two-Lane Rural Highway identifies innovative practices and devices for establishing one-lane traffic control on rural two-lane highways. Temporary traffic control, also known as maintenance of traffic, is critical to minimizing congestion and maintaining mobility during planned and unplanned activities as well as providing a safe work zone for both road users and workers. Innovative examp...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 519: The Renewal of Stormwater Systems Using Trenchless Technologies summarizes technologies used for the renewal of stormwater systems, including new, emerging, and underutilized trenchless methods, and identifies future research needs. Both trenchless replacement and trenchless renewal methods can reduce negative impacts associated with surface disruption by moving the work area outside of the travel lanes and concentrating the const...