Firms that have graduated from the federal Disadvantaged Business Enterprise (DBE) program or have successfully competed for state transportation agency contracts are the focus in NCHRP Research Report 913: Compendium of Successful Practices, Strategies, and Resources in the U.S. DOT Disadvantaged Business Enterprise Program. The DBE program provides small businesses owned and controlled by socially and economically disadvantaged persons with opportunities to participate on federally assisted highway con...

Geometric design practitioners in state transportation agencies have a new set of guidelines on probability of vehicle rollover based on various roadside design features. NCHRP Research Report 911: Guidelines for Traversability of Roadside Slopes will assist practitioners in the reduction of serious injury crashes associated with rollovers on roadside slopes. Data from the National Automotive Sampling System (NASS) Crashworthiness Data System (CDS) shows that one-third of single-vehicle run-off-road (SVR...

The distance between the driver’s line of sight along the roadway ahead on a horizontal curve and a sight obstruction on the inside of the curve is known as the horizontal sightline offset (HSO). Highway agencies can use  NCHRP Research Report 910: Design Guidelines for Horizontal Sightline Offsets as guidance to address the types of sight distance restrictions that are most likely to be encountered on specific roadway types.  The relationship between stopping sight distance (SSD) and the frequ...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Report 906 includes proposed revisions to the AASHTO LRFD Bridge Design Specifications minimum flexural reinforcement provisions for load and resistance factor design (LRFD) with detailed design examples illustrating the application of the proposed revisions. According to the AASHTO LRFD Bridge Design Specifications, minimum reinforcement provisions are intended to reduce the probability of brittle failure by providing flexural capacity...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Report 912: Guidelines for Detection and Remediation of Soluble Salt Contamination Prior to Coating Steel Highway Structures consolidates practical guidance on the detection and remediation of soluble salt contamination prior to coating steel highway structures. Soluble salts are those that dissociate in solution into anionic and cationic components. The soluble salts referenced in this guideline are soluble in water at nominal room tem...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Report 908: Acceptance Criteria of Complete Joint Penetration Steel Bridge Welds Evaluated Using Enhanced Ultrasonic Methods presents guidelines for evaluating complete joint penetration (CJP) welds in steel bridges and proposes modifications to the American Association of State Highway and Transportation Officials (AASHTO)/American Welding Society (AWS) D1.5. Inspection of welds in steel bridges is necessary to ensure the quality of wo...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Report 909: Guide to Truck Activity Data for Emissions Modeling explores methods, procedures, and data sets needed to capture commercial vehicle activity, vehicle characteristics, and operations to assist in estimating and forecasting criteria pollutants, air toxics, and greenhouse gas emissions from goods and services movement. Goods movement is a vital part of the national economy, with freight movement growing faster than passenger t...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Report 918: Approaches for Determining and Complying with TMDL Requirements Related to Roadway Stormwater Runoff has been released in pre-publication format. The report includes strategies to help improve total maximum daily load (TMDL) evaluations and assist in the decision-making process for the development of and compliance with TMDLs. The report also includes information on how to determine and address TMDL requirements related to r...

TRB’s National Cooperative Highway Research Program (NCHRP) has released the pre-publication version of NCHRP Research Report 915: Relationship Between Erodibility and Properties of Soils, which provides reliable and simple equations quantifying the erodibility of soils based on soil properties. The report a detailed analysis of the issue. In addition, the project that developed the report also produced a searchable spreadsheet that uses statistical techniques to relate geotechnical properties to soil er...

TRB's National Cooperative Highway Research Program (NCHRP)  Research Report 903: Geotechnical Asset Management for Transportation Agencies, Volume 2: Implementation Manual presents a manual that can be used to implement Geotechnical Asset Management (GAM) planning. Volume 1 , Research Overview, details the scope, process, and findings of the study. The management of bridge and pavement assets has for many years garnered significant attention by state transportation agencies while the management of ...