Migliaccio, Giovanni C., Gebken, Richard J., Fernandez, Luis R., & Osmanbhoy, Natasha (2022). Emergent Subcontracting Models in the US Construction Industry. Journal of Legal Affairs and Dispute Resolution in Engineering and Construction, 14(4).
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Abstract
Prime contracting models for engineering and construction projects are described extensively in the literature, but models between prime contractors and subcontractors are less well known. This study examined the established and evolving subcontracting models in the US construction industry to not only document their utilization but also investigate their advantages and disadvantages when employed. The research followed a two-phase/two-step approach. During Phase 1, the authors completed a regionally based study to identify subcontracting practices in the Pacific Northwest. As part of Phase 2, the study was expanded across the United States to gain a greater understanding of each of the identified subcontracting models, including advantages, disadvantages, and variations. Both phases were organized into two steps: (1) an online survey instrument was sent to professionals with either general or specialty contracting firms, and (2) follow-up semistructured interviews were conducted with selected survey respondents to better evaluate each subcontracting model. The authors found that five subcontracting models address the most common scenarios and the characteristics of each are familiar to the nationwide participant sample. There are subtle variations to the main five models that are being employed to varying degrees across the country. The impetus for these variations appears to be founded on the need to find better contractual arrangements and that subcontracting practices are dynamic by nature. Although most of the participants were from western and central divisions of the US Census Bureau geographical classification, participants from all geographic areas participated in the study. Increasing knowledge on how project delivery systems may affect disputes and claims or conflicts and legal issues of procurement systems, this article uniquely contributes to defining a taxonomy of subcontracting models while giving insights into the current and emerging trends in subcontracting practices, including how subcontractors are integrated into a project team.
Saelens, Brian E., Hurvitz, Philip M., Zhou, C., Colburn, T., Marchese, A., & Moudon, Anne Vernez (2022). Impact of a Light Rail Transit Line on Physical Activity: Findings from the Longitudinal Travel Assessment and Community (TRAC) Study. Journal of Transport & Health, 27.
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Abstract
Increasing transit infrastructure could increase transit use and result in higher physical activity if users actively travel to access transit. Few studies have rigorously examined transit use and physical activity change from before to years after among residents living close versus farther away from new transit options.Methods: An initial sample (n = 722) of residents living either close (1 mile network distance; unexposed) from future new light rail transit (LRT) stops in the Seattle/King County area were recruited and assessed prior to LRT opening and again 1-2 and 3-4 years later. At each assessment timepoint, residents wore an accelerometer and GPS data logger for 7 days and completed a 7-day travel log and demographic and attitudinal survey. Difference-in-difference analyses examined longitudinal change between those exposed versus unexposed to LRT in physical activity, walking (both utilitarian and recreational), and transit-related walking, and transit use.Results: There was no differential change by LRT exposure in overall physical activity (including or not including light intensity physical activity), recreational walking, or utilitarian walking, with most decreasing significantly in both exposure conditions through follow-ups. There was a differential change in transit-related walking, with those exposed to LRT slightly increasing such physical activity to the most distal follow-up, but the difference from the unexposed condition was modest (<2 min/day). There was no substantial differential change over time in transit use by LRT exposure.Conclusions: Exposure to a new light rail line did not markedly change the frequency of transit use of nearby residents, but did result in a small increase in transit-related walking relative to those unexposed. This did not differentially change the amount of overall physical activity or time spent walking compared to residents living farther away from the new LRT.
Keywords
Public Transit; Accelerometer Data; Built Environment; Behavior; Walking; Transportation; Neighborhood; Time; GPS
Ashour, Lamis Abu; Shen, Qing. (2022). Incorporating Ride-sourcing Services into Paratransit for People with Disabilities: Opportunities and Barriers. Transport Policy, 126, 355–363.
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Abstract
The Americans with Disabilities Act (ADA) requires public transit agencies to provide an equivalent transportation service for people with disabilities, known as ADA paratransit service. As the U.S. population continues to grow and age, the demand for paratransit service keeps rising, posing many challenges for transit agencies due to its high operational cost. In response, a growing number of transit agencies are looking to incorporate alternative paratransit services by forming partnerships with transportation network companies (TNCs) to provide what is known as same-day service (SDS). However, most of these partnerships are still in the pilot phase, and scant research investigates the opportunities and barriers of SDS or provides guidelines and measures for transit agencies interested in such partnerships. Considering both the characteristics of paratransit trips and riders and the operational norms of TNCs, this paper explores different conditions under which SDS trips are most appropriate and estimates potential trip diversion from conventional paratransit to SDS operated by TNCs. Trip diversion conditions include (1) trip length, which is impacted by the subsidy amount for SDS and the dynamic pricing of TNC trips, (2) level of service, which depends on the level of mobility assistance required by paratransit riders, and (3) the operational efficiency of conventional paratransit. Different settings and combinations of these conditions help transit agencies explore the potential trip diversion of SDS while considering significant barriers to the service. Using 2019 ridership data of Access paratransit, the ADA paratransit services in the Seattle region, this research finds that without an excessive subsidy amount, transit agencies can divert up to 18% of paratransit trips to SDS. This percentage can drop to as low as 11% of paratransit trips if transit agencies further limit the SDS service area to ensure the efficiency of conventional ADA paratransit. This paper concludes that although SDS provides many benefits, significant barriers inherent to TNC business models and paratransit users should be carefully examined when pursuing ADA paratransit-TNC partnerships.
Keywords
ADA Paratransit; Transportation network company (TNC); Ride-sourcing; Transportation equity; Public-private partnership
Wang, Yiyuan; Shen, Qing. (2022). A Latent Class Analysis to Understand Riders’ Adoption of On-demand Mobility Services as a Complement to Transit. Transportation.
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Abstract
On-demand app-based shared mobility services have created new opportunities for complementing traditional fixed-route transit through transit agencies’ efforts to incorporate them into their service provision. This paper presents one of the first studies that rigorously examine riders’ responses to a pilot aimed at providing such a transit-supplementing service. The study conducts latent class analysis on riders of the Via to Transit program, a mobility pilot in the Seattle region where on-demand service was offered to connect transit riders to light rail stations. The analysis identifies three distinct rider groups with heterogenous responses to the on-demand service: (1) riders who previously used private cars or ride-hailing; (2) riders who were pedestrians and bikers but switched likely because of safety concern; (3) mostly socio-economically disadvantaged riders who previously relied on the bus, but switched to the new service for the convenience and speed. These results point to rich transportation policy implications, which can inform decision-making by public transit agencies as they are exploring alternative ways to deliver the mobility services.
Keywords
Public transit; On-demand shared mobility; Latent class analysis; Heterogeneous travel behavior responses; Built environments
Shi, Xiao; Richards, Mary; Moudon, Anne Vernez; Lee, Brian H. Y.; Shen, Qing; & Ban, Xuegang. (2022). Changes in Perceived Work-from-Home Productivity during the Pandemic: Findings from Two Waves of a Covid-19 Mobility Survey. Findings.
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Abstract
A two-wave survey of workers in Seattle revealed an increase in self-reported work productivity over time for those who shifted to work from home (WFH) since the outbreak of Covid-19. Teleworkers with higher household income adapted better and were more likely to report an increase in productivity as they continued WFH. While those living with friends and relatives were more likely to report a decrease in productivity as they telework for longer. Commute trip reduction programs might encourage the portion of the population with such characteristics to continue WFH after the pandemic subsides and provide support to those with fewer recourses to telework productively if they choose to.
Keywords
work from home; teleworking; work productivity; commute trip reduction; transportation demand management; natural experiment; covid-19
Colburn, G., & Page Aldern, C. (2022). Homelessness is a Housing Problem. University Of California Press.
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Dannenberg, A. L., Frumkin, H., & Jackson, R. (Eds.). (2022). Making Healthy Places: Designing and Building for Health, Well-being, and Sustainability (2nd ed.). Island Press.
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Berney, R. (2022). Whose City?: Invitations and Imaginaries and the Nehemiah Initiative’s Example for Seattle. In K. Goh, A. Loukaitou-Sideris, & V. Mukhija (Eds.), Just Urban Design: The Struggle for a Public City. The MIT Press.
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Hou, J. (2022). Building Community Capacity as Just Urban Design: Learning from Seattle’s Chinatown International District. In K. Goh, A. Loukaitou-Sideris, & V. Mukhija (Eds.), Just Urban Design: The Struggle for a Public City. The MIT Press.
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Oliver, H. Pike, & Stockstill, C. Michael. (2022). Transforming the Irvine Ranch: Joan Irvine, William Pereira, Ray Watson, and the Big Plan. Routledge.
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