120 research outputs found

    Creating a Resilient Transportation Network in Skagit County: Using Flood Studies to Inform Transportation Asset Management

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    This report presents the results of a Climate Resilience Pilot Project conducted by Washington State Department of Transportation (WSDOT) and sponsored in part by the Federal Highway Administration (FHWA). WSDOT received a grant from FHWA to develop options for improving the resiliency of transportation facilities or systems to climate changes and/or extreme weather events. The pilot project set out to meet FHWA\u2019s goal of helping further the state of the practice in applying vulnerability assessment results into decision making. This study builds on WSDOT's earlier pilot by examining adaptation options in an area of the state we previously identified as highly vulnerable: the Skagit River Basin (Basin). WSDOT chose this Basin because it is the focus of a major flood study by the U.S. Army Corps of Engineers (Corps). WSDOT knew important decisions about how and where to invest in levees and other flood risk reduction projects were being actively evaluated by the Corps and the local sponsor, Skagit County. WSDOT also knew that state transportation assets were likely to be affected but were not the focus of their study. WSDOT\u2019s pilot presented the opportunity to actively engage with the flood study and search for compatible long-term solutions that create a more resilient transportation system throughout the Basin. WSDOT\u2019s pilot shows transportation planners and asset managers how to leverage a federal flood study, like the Corps\u2019 Skagit River Flood Risk Management General Investigation Study (GI study), to improve the resiliency of our highways. The pilot demonstrates how WSDOT\u2019s Vulnerability Assessment results, used in combination with federal flood study data, can reaffirm known vulnerabilities and reveal other vulnerable assets. The pilot identifies adaptation strategies for the Basin and highlights future partnership opportunities with the Corps and local governments. This report includes a series of recommendations and lessons learned that will help other DOTs and regional transportation planning entities reach across jurisdictions and sectors to create integrated asset management strategies

    Permanent Lane Marking (Recessed Lane Edge Stripe)

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    DOT-FH-11-8007The project goal was to evaluate different methods of cutting recessed skip stripe grooves, and to evaluate various pavement marking materials placed into the recesses. The project objective was to find a marking system for Washington's mountain pass highways that would tolerate snowplowing and sanding operations, studded tires, and chain wear. Three methods of pavement grooving and three types of marking materials were evaluated over a four-year period. The grooving methods were evaluated with regard to production rate, the quality of the finished groove, and cost. The marking materials were checked for ease of installation, cost, durability, and visibility. Only one method of grooving was found that produced the desired recess shape at a reasonable cost and in a timely manner. All three of the marking materials were durable enough to survive for three years, but none produced the desired wet-daytime or wet-night visibility needed for adequate lane delineation. This loss of visibility under wet conditions was due to the lack of retroreflectance from the marking materials

    Buried Concrete Barrier Ends in Washington State

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    There are over 400 buried concrete barrier ends on Washington state routes. While buried concretebarrier ends are no longer included in standard plans, it is not well understood how vehicles are interacting with these structures. An inventory of buried concrete barrier ends was matched with crash data sourced from the WSDOT Engineering Crash Datamart and the Crash Location & Analysis System (CLAS) database for the years 2011 through 2020 to determine the distribution of crashes in location and severity. During this ten-year period, 36 crashes with these ends were reported and they included only one fatal crash and no serious injury crashes. Most crashes occurred in an urban environment with almost an even split between mainline and exit ramps

    The Effects of Long-Duration Subduction Earthquakes on Inelastic Behavior of Bridge Pile Foundations Subjected to Liquefaction-Induced Lateral Spreading

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    Effective-stress nonlinear dynamic analyses (NDA) were performed for a large-diameter reinforced concrete (RC) pile in multi-layered liquefiable sloped ground. The objective was to assess the effects of earthquake duration on the combination of inertia and liquefaction-induced lateral spreading. A parametric study was performed using input motions from subduction and crustal earthquakes covering a wide range of motion durations. The NDA results showed that the pile head displacements increased under liquefied conditions, compared to nonliquefied conditions, due to liquefaction-induced lateral spreading. The NDA results were used to develop a displacement-based equivalent static analysis (ESA) method that combines inertial and lateral spreading loads for estimating elastic and inelastic pile demands

    Pilot In-service Performance Evaluation of Guardrail Terminals in Washington State

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    A pilot routine in-service performance evaluation (ISPE) was undertaken for guardrail terminals following the process outlined in NCHRP 22-33. Controlled stop, rollover, vehicle mix, and secondary impacts on the roadside and roadway were evaluated as performance measures using data sourced from the Crash Location & Analysis System (CLAS) database and the WSDOT Engineering Crash Data Mart for years 2016 through 2020. Four Performance Assessment Levels, ranging from no exclusions of crash data to exclusions of crash data limited to vehicle type and speed limit were assessed. For all five performance measures, the study found no measurable differences between the performance of the major types of guardrail terminal in use on state highways within WSDOT jurisdiction

    Pilot In-service Performance Evaluation of Impact Attenuators in Washington State

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    A pilot routine in-service performance evaluation (ISPE) was undertaken for impact attenuatorsfollowing the process outlined in NCHP 22-33. Controlled stop, rollover, vehicle mix, and secondary impacts on the roadside and roadway were evaluated as performance measures using data sourced from the Crash Location & Analysis System (CLAS) database and the WSDOT Engineering Crash Data Mart for years 2016 through 2020. Four Performance Assessment Levels, ranging from no exclusions of crash data to exclusions of crash data limited to vehicle type and speed limit were assessed. For all five performance measures, the study found no measurable differences between the performance of the major types of impact attenuators in use on state highways within WSDOT jurisdiction

    Pilot In-service Performance Evaluation of Cable Barrier in Washington State

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    A pilot routine in-service performance evaluation (ISPE) was undertaken for cable barrier following the process outlined in NCHRP 22-33. Barrier breach, rollover, vehicle mix, and secondary impacts on the roadside and roadway were evaluated as performance measures using data sourced from the Crash Location & Analysis System (CLAS) database and the WSDOT Engineering Crash Data Mart for years 2016 through 2020. Four Performance Assessment Levels, ranging from no exclusions of crash data to exclusions of crash data limited to vehicle type and speed limit were assessed. For all five performance measures, the study found no measurable difference between the performance of the four major types of cable barrier in use on state highways within WSDOT jurisdiction, including three-strand versus four-strand

    Performance of Transportation Infrastructure During Kumamoto Earthquakes of April 14 and 16, 2016\u2014 A Reconnaissance Report

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    DTFH61-07-00031This report described a reconnaissance effort to document bridge performance during the Kumamoto earthquakes in Japan in April 2016. More than 180 bridges were damaged by these earthquakes. Of particular interest is the performance of bridges that were relatively new (15\u201320 yr old) or recently retrofitted. Damage sustained was significant and included bearing and shear key failures, distortion and local buckling of the steel superstructures, and foundation movement. Most of the damage could be attributed to extensive slope failures and intense shaking close to the causative fault. Recommendations for improving bridge performance in future earthquakes are given

    Trade-Off Between Delineation and Lighting on Freeway Interchanges

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    DTFH61-85-C-00137The objective was to determine whether, with improved delineation, performance at partially lighted interchanges can approach performance under full lighting, particularly in rain. Two field studies were conducted. The first was to determine whether transient visual adaptation (TVA) influences detection on partially lighted interchanges and could interact with lighting. It was shown that TVA occurs under partial lighting and influences detection up to 600 feet from the last luminaire. The second field study was to determine the effect of lighting, weather, and improved delineation on driver performance. Data were obtained on two exits in dry and wet weather under full lighting with baseline delineation and three improved delineation systems. Partial lighting at one exit was with one luminaire, at the other with three luminaires. Findings support the contention that full lighting is superior to partial lighting in ramp speed-related measures. Analysis of delineation effects on ramp and spot speeds and on speed distributions showed few differences under dry conditions. In rain, effects were stronger but were neither large nor consistent enough to recommend improved delineation over the baseline system. Nonstatistical comparison of the results from two sited provided evidence that three-luminaire partial lighting was superior to single-luminaire. Performance on ramp segments downstream of the last luminaire suggested TVA influenced results

    A Targeted Approach to High-Volume Fly Ash Concrete Pavement (Phase I Report)

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    Unlike the conventional method of admixing nanomaterials directly in fresh concrete mixture, a more targeted approach was explored. Specifically, nanomaterials were used to improve the interface between coarse aggregate and cement paste, by coating the coarse aggregate with cement paste that contained graphene oxide or nanosilica. Using coated coarse aggregates, the mechanical and transport properties of high-volume fly ash (HVFA) concrete were tested to evaluate the effect of nanomaterial coating on the interface transition zone of concrete. The compressive and splitting strengths of HVFA concrete at 3, 7, 14, and 28 days and the water sorptivity and chloride migration coefficient at 28 days were studied. Results show that nanomaterial-coated coarse aggregate can improve the transport properties of HVFA concrete by reducing permeability. However, no improvement was seen in the compressive and splitting strengths when incorporating coated coarse aggregate, compared with direct mixing of nanomaterials in fresh concrete. Resistance to freezing/thawing cycles and scanning electron microscope/energy dispersive X-ray spectroscopy of concrete samples were also investigated to obtain a more comprehensive and mechanistic understanding of nanomaterial coating
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