TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 256: Assessing Interactions Between Access Management Treatments and Multimodal Users describes operational and safety relationships between access management techniques and the automobile, pedestrian, bicycle, public transit, and truck modes. This contractor's report may help assist in the selection of alternative access management techniques based on the safety and operation performance of each affected travel mode.The r...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 248: Research on Creating and Sustaining a Culture of Innovation for Departments of Transportation documents the research process and provides key guidance to implement the research produced in NCHRP Research Report 885 : Guide to Creating and Sustaining a Culture of Innovation for Departments of Transportation. This guide provides insight on encouraging and sustaining a culture of innovation within the organization, its partne...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 257: A Mechanistic–Empirical Model for Top–Down Cracking of Asphalt Pavements Layers develops a calibrated mechanistic-empirical (ME) model for predicting the load-related top-down cracking in the asphalt layer of flexible pavements. Recent studies have determined that some load-related fatigue cracks in asphalt pavement layers can be initiated at the pavement surface and propagate downward through the asphalt layer. However, t...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 254: Underwater Installation of Filter Systems for Scour and Erosion Countermeasures, Volume 2: Training Manual provides training on the underwater placement of filters, and can be adapted into a workshop or distance learning presentations. The project provides guidance on design procedures, material testing requirements, installation alternatives, and quality checklist items for both granular and geotextile filters. Filters ar...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 254: Underwater Installation of Filter Systems for Scour and Erosion Countermeasures, Volume 1: Research Report documents the research effort of NCHRP Research Report 887 : Guidance for Underwater Installation of Filter Systems. The project provides guidance on design procedures, material testing requirements, installation alternatives, and quality checklist items for both granular and geotextile filters. Filters are an importa...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 253: Implications of Connected and Automated Driving Systems, Vol. 4: Autonomous Vehicle Action Plan (AVAP) develops awareness of the legislative landscape and the foundational laws and regulations that may need to be prioritized for modification for Connected and Automated Driving Systems (C/ADSs) technologies. The AVAP is intended to provide guidance and resources to state departments of motor vehicles (DMVs) and transportati...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 253: Implications of Connected and Automated Driving Systems, Vol. 1: Legal Landscape explores federal, state, and international legal activities and practices regarding Connected and Automated Vehicles and Highly Automated Vehicles (C/AV/HAVs): Section 1 reviews United States federal activities within the sphere of regulating C/AV/HAVs. Section 2 reviews practices in each of the 50 states and local activities that have amended...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 253: Implications of Connected and Automated Driving Systems, Vol. 2: State Legal and Regulatory Audit assists state agencies as they work to adapt their legal programs to reflect the realities of Connected and Automated Driving Systems (C/ADSs)—a term that in this report encompasses both vehicle connectivity and an Automated Driving System. The study highlights dozens of state code provisions that may need modification or clar...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 253: Implications of Connected and Automated Driving Systems, Vol. 3: Legal Modification Prioritization and Harmonization Analysis identifies how and when regulations and laws will need to be modified to facilitate the implementation of Connected and Automated Driving Systems (C/ADSs)-equipped vehicles. The report also identifies areas in today's state motor vehicle codes and regulations where harmonization may be important in ...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 253: Implications of Connected and Automated Driving Systems, Vol. 5: Developing the Autonomous Vehicle Action Plan provides technical background on developing Volumes 1 through 4 of NCHRP Web-Only Document 253. It includes further background on terminology and definitions used in the suite of reports; legal and regulatory reviews and needs assessment; state legal and regulatory audit; a prioritization and harmonization analysi...