UW researchers explore using public-private partnerships to convert bus bases for electric-powered vehicle charging. Conversion of bus base facilities, the heart of transit operations, for electric vehicle charging is a large-scale project with many players and complex needs. One option for transit agencies working to shift to a zero-emission fleet is a public-private partnership model (P3), which defers upfront capital construction costs and has the potential to help agencies meet long-term sustainability and resiliency goals. This research out of the…
Research Theme: Infrastructure & Transportation
Includes both management/policy and design/building aspects
The Articulation and Current Practices of Liquidated Damages in Standard Specifications for Highways
Abdel Aziz, A. M., & Muiruri, K. (2023). The Articulation and Current Practices of Liquidated Damages in Standard Specifications for Highways. Journal of Legal Affairs and Dispute Resolution in Engineering and Construction, 15(4). https://doi.org/10.1061/JLADAH.LADR-959
Abstract
Delayed delivery of highway infrastructure could financially hurt businesses that rely on such facilities, disrupt the public commute, and increase road user costs. For these reasons, state highway agencies (SHAs) tend to use and enforce liquidated damages (LDs) for the contractor’s failure to meet the completion times. While SHAs may have similar experiences on how their standard specifications (SSs) are structured and written, there are differences among the states on how the LDs are articulated. Further, with their requirements, SHAs need to maintain that their LDs regulations follow and account for the Code of Federal Regulations, for example, CFR.635.127. Additionally, contractors may legally challenge the LDs enforceability as unreasonable, excessive, penalty statements, or concurrently caused. This work aims to critically examine and thoroughly analyze how LDs were articulated in the SSs. For that, the LDs sections, definitions, and contract times of the standard specifications of all departments of transportation in the United States were collected, thoroughly reviewed, compared, and analyzed. With commonalities and differences among the SSs, themes of LDs current practice were identified under LDs characterization, application periods, reference times, and implementation forms. A detailed account of the particulars of each theme and practice is discussed and explained. The work provides insights for SHAs to evaluate their current LDs practice to other states’ practices to improve how LDs provisions are articulated.
Kevin Muiruri
Research interests: project delivery methods and impact to project success; project control and construction contracts; privatization in construction and private-public partnerships; project cost management; sustainability.
M.S. Construction Management, University of Washington (2022)
B.S. Civil Engineering, Dedan Kimathi University of Technology, Kenya (2017)
Does high-speed rail mitigate peak vacation car traffic to tourist city? Evidence from China
Pan, H., Gao, Y., Shen, Q., Moudon, A. V., Tuo, J., & Habib, K. N. (2023). Does high-speed rail mitigate peak vacation car traffic to tourist city? Evidence from China. Transport Policy, 143, 93–105. https://doi.org/10.1016/j.tranpol.2023.09.011
Abstract
Tourist travel contributes greatly to transport problems in attractive tourist cities. To take full advantage of high-speed rail (HSR) for alleviating massive car traffic during the peak vacation period, this paper analyses the travel modes of domestic visitors to Shaoxing before and after the operation of HSR. Scenario-based comparison and a random-coefficients structure Mixed Logit (MXL) model with error components were adopted to analyze the travel mode change and the factors explaining tourists’ travel mode choices. Our findings show that the HSR modal share increased substantially at the expense of express buses, more than cars. Also, HSR was found to be less competitive than cars on toll-free days for medium short travel distances. The MXL model results indicate that HSR was more likely to be used over automobiles by young people, females, and one-destination travellers, for longer travel distances, and with high service frequency to Shaoxing. Besides, online booking services were highly associated with HSR use. Driving was favoured over HSR by higher income level groups, when travelling with family or friends, on toll-free national holidays. Current government policy to waive road tolls during the peak holiday period further induced car traffic to tourist cities. When individual taste was considered, tourists showed a similar preference in their valuation of the travel time variable, while were heterogenous in their preference for low per-distance cost. Our findings suggest that the adjustment of the road-toll policy, pre-booking design for targeted tourists, and measures to reduce the total travel time of HSR should be considered to promote HSR as well as impede the use of cars during peak periods. This study offers empirical evidence of achieving effective travel demand management and reducing car dependence through HSR and complementary measures.
Keywords
High-speed rail; Tourist mode choice; Tourist travel package; Travel demand management
An Economic Analysis of Incorporating New Shared Mobility into Public Transportation Provision
Wang, Y., & Shen, Q. (2023). An economic analysis of incorporating new shared mobility into public transportation provision. Transport Policy, 141, 263–273. https://doi.org/10.1016/j.tranpol.2023.07.025
Abstract
Transit agencies in the US have shown great interests in the possibility of incorporating on-demand shared mobility modes into their fixed-route transit services. However, the cost-effectiveness of on-demand modes has not been clearly demonstrated, and there lacks an effective method for transit agencies to compare the costs of different service provision options. This study develops an economic-theory-based framework that appropriately conceptualizes the total economic cost of incorporating on-demand modes into transit. Based on the theoretical framework, a simulation model is built to operationalize an approach for evaluating the cost-effectiveness of transit-supplementing, on-demand mobility services. We demonstrate the applicability of this approach using Via to Transit program in the Seattle region. By accounting for both the service provider's cost and the users' cost, we obtain a more complete and accurate measure for the cost advantages of the on-demand modes in this case in comparison to expanding fixed-route transit, where the total economic cost for the on-demand mode is 22% lower than the fixed route transit. The theoretical framework and the simulation model can support the decision-making of public transit agencies as they explore incorporating mobility on demand to supplement traditional transit.
Keywords
Public transit; On-demand shared mobility; Marginal cost; Generalized travel cost; Transportation simulation
Hoseok Sa
Research Interests: Regional econ. development (tech innovation, human capital, regional industry), Transportation planning/policy (travel behavior, mobility, sustainable transportation), intersection between planning (or transportation), population/public health, and climate change, and urban form
Urban Infrastructure Lab Report on High-Speed Rail
The Urban Infrastructure Lab researchers have released a report on a Cascadia region high-speed rail project. College of Built Environments faculty Jan Whittington and Qing Shen were authors on the report, along with 3 Interdisciplinary Ph.D. in Urban Design and Planning students (Siman Ning, Haoyu Yue, and Chin-Wei Chen), and a Master of Urban Planning candidate (Richard McMichael). This report examines the successes and lessons learned from existing high-speed rail projects in Europe and Asia, including 50 hours of interviews…
ACT²: Time–Cost Tradeoffs from Alternative Contracting Methods
Choi, Kunhee, Bae, Junseo, Yin, Yangtian, and Lee, Hyun Woo. (2014). ACT²: Time–Cost Tradeoffs from Alternative Contracting Methods. Journal of Management in Engineering, 37(1).
Abstract
Incentive/disincentive (I/D) and cost-plus-time (A+B) are two of the most widely used alternative contracting methods (ACMs) for accelerating the construction of highway infrastructure improvement projects. However, little is known about the effects of trade-offs in terms of project schedule and cost performance. This study addresses this problem by creating and testing a stochastic decision support model called accelerated alternative contracting cost-time trade-off (ACT2). This model was developed by a second-order polynomial regression analysis and validated by the predicted error sum of square statistic and paired comparison tests. The results of a descriptive trend analysis based on a rich set of high-confidence project data show that I/D is effective at reducing project duration but results in higher cost compared to pure A+B and conventional methods. This cost-time trade-off effect was confirmed by the ACT2 model, which determines the level of cost-time trade-off for different ACMs. This study will help state transportation agencies promote more effective application of ACMs by providing data-driven performance benchmarking results when evaluating competing acceleration strategies and techniques.
Keywords
Errors (statistics), Project management, Benefit cost ratios, Regression analysis, Construction costs, Infrastructure construction, Contracts and subcontracts, Construction methods
College of Built Environments Announces 2023 Inspire Fund Awards
In 2021, the College of Built Environments launched the CBE Inspire Fund to “inspire” CBE research activities that are often underfunded, but for which a relatively small amount of support can be transformative. The Inspire Fund aims to support research where arts and humanities disciplines are centered, and community partners are engaged in substantive ways. Inspire Fund is also meant to support ‘seed’ projects, where a small investment in early research efforts may serve as a powerful lever for future…
Designing Bike-Friendly Cities: Interactive Effects of Built Environment Factors on Cycling
Wang, Lan, Kaichen Zhou, Surong Zhang, Anne Vernez Moudon, Jinfeng Wang, Yong-Guan Zhu, Wenyao Sun, Jianfeng Lin, Chao Tian, and Miao Liu. 2023. “Designing Bike-Friendly Cities: Interactive Effects of Built Environment Factors on Cycling.” SSRN Electronic Journal.
Abstract
Geographical detector models facilitate a comprehensive approach to urban Design. • Interaction detector measures combined effects of the built environment on Cycling. • Street network centrality has the largest explanatory power on cycling. • A sense of enclosure defined by streetscape elements encourages cycling. Designing bike-friendly cities could promote health and mitigate climate change. Most studies of the association between the built environment and cycling used the "5Ds" framework and linear modeling. However, the built environment exerts complex influences on travel behavior. To better inform urban design for cycling, this study employed geographical detector models that quantify the explanatory power of individual and interactively paired built environment factors on bike-sharing. Data came from 6.5 million bike-sharing orders in Shanghai. Expectedly, we found that street network centrality and important facilities like supermarkets and libraries have the greatest independent and interactive effects. More surprisingly, streetscape elements, including sky view and building frontage, offered significantly higher explanatory power when paired with each other or with street network centrality and important facilities. By identifying the overlooked interactive effects of urban environment factors, the study provides guidance for urban designers to consider combinations of factors that effectively promote cycling. [ABSTRACT FROM AUTHOR]
Keywords
Bike-friendly city; Cycling; Street view images; Urban design