TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 194: Traffic Law Enforcement in Work Zones: Phase II Research is contractor’s final report providing background information for the project that produced NCHRP Report 746 Traffic Enforcement Strategies for Work Zones. NCHRP Report 746 presents guidance for the safe and effective deployment of traffic enforcement strategies in work zones on high-speed highways.

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 196: Final Research Report: A Transportation Guide for All-Hazards Emergency Evacuation documents the development of the  NCHRP Report 740 that focuses on the transportation aspects of evacuation--particularly large-scale, multijurisdictional evacuation.

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 197: Guidelines for the Load and Resistance Factor Design and Rating of Riveted and Bolted Gusset-Plate Connections for Steel Bridges explores the failure modes of steel truss bridge gusset plated connections. The report also includes a review of past literature on the strength of hot-driven rivets. The following appendices are not included in the PDF version of the report, but are available for download from the links below. A...

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 193: Development of Left-Turn Lane Warrants for Unsignalized Intersections provides background on the development of NCHRP Report 745 : Left-Turn Accommodations at Unsignalized Intersections.

TRB National Cooperative Highway Research Program (NCHRP) Web-Only Document 195: Driving Forces Influencing Future Freight Flows includes a detailed discussion on the driving forces behind high-impact economic and social changes as well as sourcing patterns that may affect the U.S. freight transportation system. An analysis of the driving forces was published as NCHRP Report 750: Strategic Issues Facing Transportation, Volume 1: Scenario Planning for Freight Transportation Infrastructure Investment .

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 198: Sag Vertical Curve Design Criteria for Headlight Sight Distance reviews the current methodologies used in the design of sag vertical curves and changes in headlamp technologies. The report also highlights potential changes to the American Association of State Highway and Transportation Officials (AASHTO) design guide as a result of these reviews.

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 192: Deployment, Use, and Effect of Real-Time Traveler Information Systems explores the deployment, use, and effect of real-time traveler information (TI) systems. The report examines transportation agency dissemination practices, assesses traveler perception and use of TI systems, and offers best practices on ways to implement TI systems.

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 191: Analysis of Managed Lanes on Freeway Facilities evaluates the performance of managed lane facilities on freeways.

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 190: Structural Design of Culvert Joints explores the effect of longitudinal bending on joints in rigid (reinforced concrete) and flexible (corrugated steel and thermoplastic) culverts. The report examines two joint types--those that release the longitudinal bending moments (denoted ‘moment-release joints’) like gasketted bell and spigot joints, and those that transfer them (denoted ‘moment-transfer joints’) such as band connec...

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 189: Design and Management of Historic Roads explores how the inherent flexibility in the current policies, manuals, criteria, rules, standards, and data sets that underlie the transportation planning and project development process may be used to preserve historic roads and roads in historic districts and settings.