Current Research

The UW, WSU, and WSDOT recently developed a multi-modal statewide GIS model hat can help the state prioritize strategies that protect industries most vulnerable to disruptions, supporting economic activity in the state and increasing economic resilience. The proposed research was identified at the conclusion of that project as an important step in improving the model's ability to measure the impact of disruptions. In addition to developing the model, the researchers developed two case studies showing the model's capabilities: the potato growing and processing industry was chosen as a representative agricultural sector, and diesel fuel distribution for its importance to all industry sectors. As origin-destination data for other freight-dependent sectors is added to the model, WSDOT will be able to evaluate the impact of freight system disruptions on each of them. Moving forward, it is not cost effective to develop case studies in the manner used for these case studies, therefore, the state is currently supporting activities at the national level that will provide methods for collecting statewide commodity flow data. However, this commodity flow data will still lack important operational detail necessary to understand the impacts of transportation changes. This research will begin to fill that gap by developing a transportation-based categorization of logistics chains. The goal is not to capture all of the complexity of supply chain logistics, but to identify approximately 15-20 categories within which supply chains behave similarly from a transportation perspective, for example, in their level of scheduling and methods for route selection. Researchers will use existing publicly available data, conduct an operational survey, and analyze GPS data collected for WSDOT's freight performance measures project to identify the categorization.

Despite the importance of trucks in moving freight, little is known about their travel patterns. Fortunately, commercial fleet management GPS devices provide a new source of truck probe data. A previous project by TransNow used these data to develop performance measures. In this proposed project, three research steps will enhance the value of GPS data and provide more usable input for freight planning models and performance measures. Vehicle Classification: The GPS data, because of data limitations or privacy suppression, contain minimal information about truck size and class and almost no information on the freight being moved. This project, working with GPS vendors, will develop a methodology for classifying the trucks supplying the GPS data by type and size. This classification tool could look at the travel characteristics, origins, and destinations of the trucks and create classification algorithms that could include commodity information. Trip Generation: Because the GPS data are location specific, it is possible to determine the number of truck trips generated by specific types of warehouses, stores, port, and more. This research will develop a methodology for using the GPS truck database and GIS processing tools, in conjunction with truck activity information from other sources, to develop truck trip generation rates. Identifying Truck Trip Origins and Destinations: Both performance measures and freight models require an understanding of the travel patterns of trucks. This requires information about travel generated by trucks as they respond business needs to be extracted from the GPS data. Such extraction involves identifying each origin and destination where a truck stops to complete the transaction that defines the purpose of each truck's trip. Because GPS devices record all stops, research is required to develop a robust methodology that can differentiate between traffic-based stops and stops at origins and destinations.

Greenroads is a sustainability rating system for roadways. It is being developed at the University of Washington (UW) under 3 different projects, one of which is funded by TransNow for FY 2010. CH2M HILL is a partner in this development and has contributed their own internal funds and time in a process completely separate from UW funding. Detailed Greenroads information can be found at: www.greenroads.us. Greenroads Version 1.0 is complete. The current focus of this project is to investigate its use and impact on actual roadway projects. This involves partnering with owner agencies and consultants to select "pilot projects" that will intentionally pursue a Greenroads rating certification level and actively use the rating system to influence the design and construction phases of a roadway project. The Greenroads team, in conjunction with these partners will evaluate the following: (1) feasibility of using the system, (2) potential modifications to the rating system based on use, (3) potential for formal adoption by pilot project partners, (4) initial and life cycle cost impacts of a Greenroad, and (5) workflow of project application, review and certification. The end goal is to have Greenroads be the roadway rating system of choice in the U.S.

Congestion pricing aims at optimizing network-wide traffic allocation to mitigate traffic congestion and has been regarded as one of the most effective countermeasures against urban traffic congestion. Through dynamically adjusting tolls in the horizon of both time and space dimensions, toll-based traffic management is expected to effectively mitigate congestion and improve traffic mobility. However, preliminary studies on toll impacts found that travel patterns and infrastructure utilization vary significantly with toll settings. To quantify such impacts, further research is needed. Simulation-based investigation on traffic system operations provides a cost-effective, risk-free, and prospective means of exploring optimal management strategies, identifying potential problems, and evaluating various alternatives. VISSIM is a microscopic driver behavior-based traffic simulation tool, employed widely by transportation professionals. Although VISSIM provides a powerful platform for general traffic simulations, its application on toll-based operations is limited because its built-in modules cannot be used supporting customized tolling strategy simulation.

In this study, a simulation-based testbed for analyzing toll impacts on freeway travel is proposed. A new external module will be developed via VISSIM Component Object Model (COM) interfaces. This external module can provide sufficient flexibility to satisfy any specific demands from particular researchers and practitioners. Efforts will be made to calibrate driving behavior parameters in the simulation model using drivers’ characteristic data to enhance the creditability of simulation experiments. Furthermore, a method for statistically analyzing traffic simulation outputs and examine simulation reliability will be developed. The methodology developed in this proposal is applicable for quantitatively evaluating impacts of toll-based traffic operations on freeway travel.

A current focus in bridge engineering is accelerated bridge construction (ABC) to minimize costs. Concurrently, maximizing sustainability in built systems is a national priority. A concrete-filled tube (CFT) bride pier system is proposed to achieve both. CFTs are structurally and seismically efficient with steel at the optimum location and reduce size and materials negating the need for formwork or reinforcement. CFTs constructed using recycled steel and concretes with a high percentage of supplementary cementitious materials (SCMs) to replace the cement will maximize the recycled/waste materials and minimize the embedded carbon content. Current design standards limit SCMs to 40%, largely because of uncertainties in the strength and required cure time. In this system, the impact of elongate cure time is minimized since the steel shell sustains the demands as the concrete cures. Long-term, the concrete fill restrains tube buckling and the tube prevents concrete spalling thereby reducing seismic damage and the need to replace the bridge after an earthquake, further enhancing sustainability. The CFT containing SCM-concrete is a unique concept that will enhance the constructability, sustainability and seismic performance of bridges. This study is conducted in two phases. In the first phase, concretes with 60-100% SCMs were tested to evaluate long and short-term compressive capacity and develop companion engineering expressions which are needed by bridge engineers to actually use these materials in primary structural systems. The second phase focuses on the CFT bridge pier itself to establish the short and long-term response including creep, stiffness and strength of the composite component. The project is collaborative with CA and WA DOT-sponsored research, which are studying connections and design methods. The combined research efforts will result in engineering methods for the SCM-CFT piers and connections to enhance sustainability, seismic performance and ABC.

This project contributes to developing a technical infrastructure to support the Safe Routes to School (SRTS) Program, specifically to monitor its growth and to evaluate its effectiveness. Since its inception in 2005, the SRTS program mandated by SAFETEA-LU has benefited about 6,489 schools nationally. The goals are to insure the safety of children attending schools and to encourage their walking and biking to school. Programs use the 4 Es—engineering, education, encouragement, and enforcement—to monitor and evaluate their success. The National Center for Safe Routes to School keeps track of these schools by compiling tallies of children walking or biking to school and by collecting parent surveys. Each state works to have a fair and effective distribution of resources to the neediest schools. This proposal adds to an on-going Pooled Fund project spearheaded by the Washington State Department of Transportation to support information exchanges and research between several participating states, including Florida, Texas, Mississippi, and Wisconsin. Over the past two years, the PI and her team have been working with WSDOT to provide technical support to members of the Pooled Fund. This proposal is to fill a relatively small but very important gap in the current knowledge about SRTS: that is the lack of data on the schools’ specific locations. Having spatial data on the location of schools will facilitate the selection of SRTS projects and the monitoring the SRTS programs over time. We propose to geocode schools nationwide in relation to existing transportation facilities. This would enable state SRTS coordinators to quickly evaluate the schools proximity to different types of transportation facilities and to establish their related level of exposure to traffic. Geocoded schools would also allow coordinators to analyze the characteristics of the neighborhoods around the schools based on spatial data that are readily available from the US Census.

A select number of University Transportation Centers (UTCs) in the federal UTC Program are working with their local and regional partners to conduct research and develop educational materials that address national freight issues. The goal of the proposed project is to foster collaboration among these various stakeholders, share information, and provide university students and practicing professionals with the tools they need for successful careers in this important transportation area. The proposed project will take the first step toward developing a multi-UTC program of courses that can be accessed by students at each individual UTC for course credit in their respective graduate transportation programs. Courses that cover specialty areas such as freight transportation can be offered by more universities with transportation programs if we can effectively exploit UTC resources collectively. The proposed project will investigate the feasibility of this approach by developing a graduate seminar that bring together experts and faculty from several UTCs in a web-based, real-time format. The project funds will be used to plan, design, and implement the seminar in its first year. While the seminar will be primarily organized and implemented during this time by the TransNow UTC director, the seminar will be jointly supported by other UTCs with a strong interest in freight transportation, namely, The National Center for Freight and Infrastructure Research and Education (CFIRE), METRANS, and the Texas Transportation Institute. In future years we expect that the leadership of the seminar will be shared across these, and other interested UTCs. The project will initiate with a scoping phase, where representatives from the four UTCs will work together to develop a seminar theme, a schedule for the seminar, and responsibility amongst the UTCs for each class session. Initial conversations suggest a strong interest in sharing knowledge and experience regarding creating and maintaining relationships with regional agencies, corporations, and institutions. The Pacific Northwest has a strong history of developing effective cooperative groups that we would like to showcase, including the Puget Sound Freight Mobility Roundtable, and Whatcom County's International Mobility and Trade Corridor. METRANS has worked very effectively with cities in its region, and CFIRE organizes the Mississippi Valley Freight Coalition.

Rapid construction of bridges has become increasingly important as traffic congestion on the nation's highways worsens. Construction can be accelerated by use of administrative changes to contracting methods, by financial incentives, and by new physical approaches to construction. In many cases all three are necessary, and the appropriate mix must be determined on a job-by-job basis. The most promising physical approach is to prefabricate components, thereby minimizing the time needed for site assembly. However, this poses particular problems in seismic regions, because the connections needed to join the components must be able to resist the seismic forces. Unfortunately these are largest at the intersection of the beams and columns, which is also the most convenient location for the connections. Thus the connections must be both easy to construct, with generous tolerances, and be able to accommodate large seismic forces. Designing connections to satisfy this combination of requirements is difficult. The work proposed here builds on previous success in developing connections for bridge frames, known as bents, on which the longitudinal girders are supported. With the help of TransNow funding, we have developed a bridge bent system that gains its construction speed through precasting the concrete components, and which has been shown in tests to have seismic performance equivalent to or better than, conventional, code-compliant systems. It is sustainable because the precast concrete members are designed to "bounce back" during an earthquake, and to suffer less damage than a conventional system, thereby reducing the potential down-time after an earthquake and the need for repair. It also reduces lane closures and construction time, with the associated waste of fuel and carbon impact. That framing system was designed to work with spread footings. They were selected partly because the WSDOT had sufficient interest that they wanted to use the technology to construct a bridge (which is due to be bid in the summer of 2010), and partly because we were working with a contractor who wanted to try out an embryonic form of the system. (That bridge is now nearing completion over SR 520 in Redmond). In both cases, spread footings were the appropriate foundation choice. The success of the system is demonstrated by the fact that it is being used. However, the majority of bridges in the Pacific Northwest are built on deep foundations rather than spread footings. In particular drilled shafts are being used increasingly often. These are large diameter (e.g. 10ft) piles that are cast in a drilled hole in the ground. We therefore propose to modify the connection system that we have developed for spread footings so that it can be used for drilled shafts. This will allow the benefits of the system to be used on a much wider range of bridges.