University of Washington

19 2014-2015 Annual Report • Project: Determination of Creep Compliance and Indirect Tensile Strength for Mechanistic- Empirical Pavement Design Guide (MEPDG) • PI: Haifang Wen (WSU), haifang_wen@wsu.edu Pavement condition greatly affects the safety of driver. For instance, the rutting in wheelpath creates hydroplaning which can leads to loss of control of vehicles. The roughness, e.g. potholes, can pose safety hazards to the driver. Therefore, improving the pavement condition by designing cost-effective long-lasting pavement is of paramount importance. The adoptions of Mechanistic- Empirical Pavement Design Guide (MEPDG) align well with this goal, when compared to traditional empirical pavement design. Dynamic modulus, indirect tensile (IDT) creep compliance and strength are the three primary mechanistic properties of asphalt mix for the asphalt pavement in the MEPDG. Thermal cracking is one of dominant distresses in Northern States in the U.S. Based the NCHRP 01-40, the thermal cracking prediction by the Pavement ME is very sensitive (highest category) to the IDT creep compliance and IDT strength. The MEPDG is a significant improvement over empirical design method and the models in MEPDG were developed based on national database of material properties and are not applicable to local materials. Therefore, there needs a local calibration of models and establishment of catalog of typical material properties, including IDT creep compliance and strength at low temperature, for local material. Without catalog of material properties in a state, the calibration of models would not be valid. The objective of this proposed research is to develop catalogs of IDT creep compliance and IDT strength for thermal cracking for materials in Idaho. • Project: Safe Main Street Highways (SMSH) • PI: Anne Vernez Moudon (UW), moudon@uw.edu Increases in non-motorized travel also raise important safety issues, as pedestrians and bicyclists constitute the most vulnerable road users. Therefore, tools to identify locations with a high risk of collisions between motor-vehicles and pedestrians or bicyclists are essential to insure that gains in mobility, air quality, and health are not accompanied by higher rates of injuries and fatalities in vulnerable road users. The overall goal of this project is to assist in complying with Washington State Strategic Highway Safety Plan of zero fatality and serious injury by 2030, and in reducing the number of pedestrian and bicyclists involved in motor-vehicle collisions on state highways. • Project: An Evaluation of Safety Impacts of Seattle's Commercial Delivery Parking Pricing Project • PI: Anne Goodchild (UW), annegood@uw.edu • Co-Investigators: Edward McCormack (UW) The City of Seattle Department of Transportation (SDOT) conducts the Commercial Vehicle Pricing Project in order to improve commercial vehicle load zone access and efficiency in downtown Seattle and more, yet the project does not provide an understanding of the extent to which commercial vehicles circle while looking for available load zones or use parking areas outside of designated load zones. The proposed study will identify the correlations between collision rates and commercial vehicle on-street parking activity. In doing so, it will inform SDOTs revised strategies for Commercial Vehicle Load Zone location, pricing, and design, supporting the design of a safe and commercially accessible urban core.

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