Cai, M., Shen, Q., Wang, Y., Brown, M., Ban, X., & Ashour, L. A. (2024). Examining commute mode choice of essential workers before and during the COVID-19 pandemic – A case study of the University of Washington. Case Studies on Transport Policy, 15, 101129-. https://doi.org/10.1016/j.cstp.2023.101129
View Publication
Abstract
During disruptive events and major crises such as the COVID-19 pandemic, essential workers, defined in this study as employees who must continue to make frequent commute trips, play a critical role in maintaining the basic function of society. It is therefore vital for transportation planners and policymakers to ensure that adequate mobility services are provided to meet the travel needs of this group of workers. To better understand essential workers' mobility barriers and inform future transportation policy, this research examines their pre-and during-pandemic commutes, as well as prospects on future commuting, using data from the Transportation Needs Assessment Survey conducted by the University of Washington in Seattle. The results show that, first, over 60% of pre-pandemic public transit riders switched to other modes, especially driving alone. In contrast, almost all the essential workers who drove alone, biked, or walked before the pandemic continued to do so during the pandemic. Second, the shift to driving alone was most pronounced among essential workers with high incomes, whereas public transit remained as a primary mode choice of lower-income groups. As travel distance increased, the probability of driving alone over public transit also went up, although the relationship was not linear. We did not find consistently significant associations between mode choice and other sociodemographic variables. Finally, our analysis indicated that most essential workers anticipated to return to their pre-pandemic commute frequency and mode choice when the pandemic is under control. Transportation planners and policymakers can facilitate mobility for essential workers through planning and policy innovations, especially during disruptive events and major crises.
Keywords
Essential workers; Transportation equity; Mode choice; Commuting; COVID-19
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…
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
View Publication
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.
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)
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
View Publication
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
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
View Publication
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
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
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…
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).
View Publication
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
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…