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West Seattle Bridge Case Study (Phase I)

Background
West Seattle is an area of the city of Seattle located on a peninsula west of the Duwamish waterway and east of the Puget Sound. In March 2020, the West Seattle High Bridge (WSHB), the main bridge connecting West Seattle to the rest of the city, was closed indefinitely to traffic due to its increasing rate of structural deterioration. Moreover, access to the Spokane Street Lower Bridge, a smaller bridge connecting West Seattle with Harbor Island and the rest of the city, was also restricted; prioritizing heavy freight, public transit, and emergency vehicles. After the bridge closure and restrictions, the total number of vehicle travel lanes crossing the Duwamish River was reduced from 21 to 12.

The unexpected closure of WSHB disrupted passenger and freight mobility to and from West Seattle, increasing travel times and generating bottlenecks on the remaining bridges, which can potentially negatively impact the livability of the peninsula as well as its economy and the environment. The situation might further deteriorate as traffic demand to and from West Seattle increases during recovery from the COVID-19 pandemic.

The Seattle Department of Transportation (SDOT) is taking actions to monitor changes in travel behavior to/from West Seattle and identify and implement strategies that could mitigate the negative impacts caused by the WSHB closure.

Goals
SDOT has engaged the Urban Freight Lab to conduct research to explore strategies to alleviate congestion impacts and minimize the disruption of goods and service delivery to West Seattle.

The purpose of this study is to support SDOT to:

  1. understand current freight movements and freight demand in West Seattle;
  2. identify a data-driven mitigation strategy for freight and service flow to and from West Seattle;
  3. assess ex-ante the effectiveness of an implemented strategy.

The freight operations considered and analyzed within the scope of the project are consumer goods and services destined for West Seattle residents and businesses. Intermediate goods and raw materials destined for construction of production and other goods transiting through West Seattle but not destined for local residents or businesses will not be studied.

Continuation
This project continues with the West Seattle Bridge Case Study Phase II.

Paper

Would Being Driven by Others Affect the Value of Travel Time? Ridehailing as an Analogy for Automated Vehicles

 
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Publication: Transportation
Volume: 46
Pages: 2103–2116
Publication Date: 2019
Summary:

It is widely believed that vehicle automation will change how travelers perceive the value of travel time (VoTT), but the magnitude of this effect is still unknown. This study investigates how highly automated vehicles (AVs) may affect VoTT, using an existing mode—ridehailing services (RHS)—as an analogy for AVs.

Both AVs and RHS relieve travelers from the effort of driving and allow them to participate in other activities while traveling. In a stated choice experiment, respondents chose between driving a personal vehicle or taking an RHS, with each mode characterized by a cost and travel time.

Analysis results using a mixed logit model indicated that the VoTT was 13% lower when being driven in an RHS than when driving a personal car. We also told half the respondents (randomly selected) that the RHS was driverless; and for half (also randomly selected) we explicitly mentioned the ability to multitask while traveling in an RHS. Mentioning multitasking explicitly led to a much lower VoTT, approximately half that of driving oneself. However, the VoTT in a driverless RHS was 15% higher than when driving a personal car, which may reflect a lack of familiarity and comfort with driverless technology at present.

These results suggest sizable reductions in VoTT for travel in future AVs, and point to the need for caution in making forecasts based on consumers’ current perceptions of AV technology.

Authors: Dr. Andisheh Ranjbari, Jingya Gao, Don MacKenzie
Recommended Citation:
Gao, J., Ranjbari, A. & MacKenzie, D. Would being driven by others affect the value of travel time? Ridehailing as an analogy for automated vehicles. Transportation 46, 2103–2116 (2019). https://doi.org/10.1007/s11116-019-10031-9
Paper

Evaluating Traffic Impacts of Permitting Trucks in Transit-Only Lanes

 
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Publication: Transportation Research Record: Journal of the Transportation Research Board
Publication Date: 2021
Summary:

With ongoing population growth and rapid development in cities, the demand for goods and services has seen a drastic increase. Consequently, transportation planners are searching for new ways to better manage the flow of traffic on existing facilities, and more efficiently utilize available and unused capacity. In this research, a lane management strategy that allows freight vehicles to use bus-only lanes is empirically evaluated in an urban setting. This paper presents an analysis of data that was collected to evaluate the operational impacts of the implementation of a freight and transit (FAT) lane, and to guide the development of future FAT lane projects by learning from the case study in Seattle, U.S. The video data was converted to vehicle counts, which were analyzed to understand the traffic impacts and used to construct a discrete choice model. The analysis shows that transit buses used the FAT lane 96% of the time, and authorizing trucks to use the lane did not affect that lane choice. Trucks used the FAT lane, but their utilization decreased with increasing numbers of buses in the FAT lane. Instead of higher rates of trucks, unauthorized vehicles, such as passenger cars and work vans, increasingly used the FAT lane during congestion. As a result of their differing schedule patterns, trucks and buses used the FAT lane at complementary times and trucks showed relatively low volumes in the FAT lane. Overall, the results are promising for a lane management strategy that may improve freight system performance without reducing transit service quality.

Recommended Citation:
Gunes, S., Goodchild, A., Greene, C., & Nemani, V. (2021). Evaluating Traffic Impacts of Permitting Trucks in Transit-Only Lanes. Transportation Research Record. https://doi.org/10.1177/03611981211031888
Paper

Impact of Transit Network Layout on Resident Mode Choice

 
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Publication: Mathematical Problems in Engineering
Volume: 4
Publication Date: 2013
Summary:
This study reviews the impact of public transit network layout (TNL) on resident mode choice. The review of TNL as a factor uses variables divided into three groups: a variable set without considering the TNL, one considering TNL from the zone level, and one considering TNL from the individual level. Using Baoding’s travel survey data, a Multinomial Logit (MNL) model is used, and the parameter estimation result shows that TNL has significant effect on resident mode choice. Based on parameter estimation, the factors affecting mode choice are further screened. The screened variable set is regarded as the input data to the BP neural network’s training and forecasting. Both forecasting results indicate that introducing TNL can improve the performance of mode choice forecasting.

 

 

Authors: Dr. Ed McCormack, Jian Gao, Peng Zhao, Chengxiang Zhuge, Hui Zhang
Recommended Citation:
Gao, J., Zhao, P., Zhuge, C., Zhang, H., & McCormack, E. D. (2013). Impact of Transit Network Layout on Resident Mode Choice. Mathematical Problems in Engineering, 2013.

Managing Increasing Demand for Curb Space in the City of the Future

This research aims to develop innovative methods for managing curb lane function and curb access. The rapid rise of autonomous vehicles (AV), on-demand transportation, and e-commerce goods deliveries, as well as increased cycling rates and transit use, is increasing demand for curb space resulting in competition between modes, failed goods deliveries, roadway and curbside congestion, and illegal parking.

The research findings will improve mobility by increasing the understanding of existing curb usage and provide new solutions to city officials, planners, and engineers responsible for managing this scarce resource in the future.

The research team will work closely with several cities in the PacTrans region to ensure the study’s relevance to their needs, and that the results will be broadly applicable for other cities.

This research will allow for the development of innovative curb space designs and ensure that our urban street system may operate more efficiently, safely, and reliably for both goods and people.

Technical Report

Analyzing the Long-Term Impacts of COVID-19 Disruption on Travel Patterns

 
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Publication Date: 2020
Summary:

The rapid spread of COVID-19 pandemic in the U.S. spurred many state governments to take extensive actions for social distancing and issue stay-at-home orders to reduce the spread of the virus. Washington State and all other States in the PacTrans region have issued stay-at-home orders that include school closures, telecommuting, bars/restaurants closures, and group gathering bans, among others. These actions create significant changes to daily life and while some travel patterns will gradually restore by the end of outbreak, some may remain changed for a much longer period.

Behaviors that may see a lasting response include commuting, grocery shopping, business meetings, and even social interactions. Working from home for 2-3 months may change people’s attitudes toward telecommuting, and some may continue to do so a few days a week once the stay-at-home orders are lifted. Some employers may also shift their telecommute policies and provide/encourage working from home. In recent years, with the growth of e-commerce, many grocery stores had started to offer home deliveries; however, online grocery shopping experienced a fast and sudden boom during the pandemic. This has resulted in quick service adoption, and therefore some people may continue to do online grocery shopping once things go back to normal. Moreover, as people shift to online grocery shopping, they may proactively make a list and place orders less frequently compared to them going to store, resulting in fewer shopping trips. Some business meetings and even personal gatherings may also move online as people learn about and try alternate ways of communicating during the outbreak. Some may also consider enrolling in distant learning programs instead of attending in-person educational programs. There may also be significant changes in modes of travel. Some transit commuters may choose other modes of transportation for a while, and people may choose to drive or bike instead of taking a ride-hailing trip.

The goal of this research is to understand how COVID-19 disruption has affected people’s activity and travel patterns during the pandemic, and how these changes may persist in a post-pandemic era.

Authors: Dr. Andisheh Ranjbari, Parastoo Jabbari, Don MacKenzie
Recommended Citation:
Mackenzie D., Jabbari P., Ranjbari A. Analyzing the Long-Term Impacts of COVID-19 Disruption on Travel Patterns. Pacific Northwest Transportation Consortium (PacTrans). 2020. http://hdl.handle.net/1773/46655.
Paper

The Automated Driver as a New Road User

 
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Publication: Transport Reviews
Pages: 23-Jan
Publication Date: 2020
Summary:

Although road infrastructure has been designed to accommodate human drivers’ physiology and psychology for over a century, human error has always been the main cause of traffic accidents. Consequently, Advanced Driver Assistance Systems (ADAS) have been developed to mitigate human shortcomings. These automated functions are becoming more sophisticated allowing for Automated Driving Systems (ADS) to drive under an increasing number of road conditions. Due to this evolution, a new automated road user has become increasingly relevant for both road owners and the vehicle industry alike. While this automated driver is currently operating on roads designed for human drivers, in the future, infrastructure policies may be designed specifically to accommodate automated drivers. However, the current literature on ADSs does not cover all driving processes. A unified framework for human and automated driver, covering all driving processes, is therefore presented. The unified driving framework, based on theoretical models of human driving and robotics, highlights the importance of sensory input in all driving processes. How human and automated drivers sense their environment is therefore compared to uncover differences between the two road users relevant to adapt road design and maintenance to include the automated driver. The main differences identified between human and automated drivers are that (1) the automated driver has a much greater range of electromagnetic sensitivity and larger field of view, and (2) that the two road users interpret sensory input in different ways. Based on these findings, future research directions for road design and maintenance are suggested.

Authors: Dr. Ed McCormack, Ane Dalsnes Storsaeter, Kelly Pitera
Recommended Citation:
Storsæter, A. D., Pitera, K., & McCormack, E. D. (2020). The automated driver as a new road user. Transport Reviews, 1–23. https://doi.org/10.1080/01441647.2020.1861124
Paper

Bringing Alleys to Light: An Urban Freight Infrastructure Viewpoint

 
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Publication: Cities
Volume: 105
Publication Date: 2020
Summary:

There is growing pressure in cities to unlock the potential of every public infrastructure element as density and demand for urban resources increase. Despite their historical role as providing access to land uses for freight and servicing, alleys have not been studied as a resource in modern freight access planning.

The authors developed a replicable data collection method to build and maintain an alley inventory and operations study focused on commercial vehicles. A Seattle Case study showed that 40% of the urban center city blocks have an alley. 90% of those alleys are wide enough to accommodate only a single lane for commercial vehicles. 437 parking operations were recorded in seven alleys during business hours and found that all alleys were vacant 50% of the time.

This confirms that, in its alleys, Seattle has a valuable resource as both space for freight load/unload; and direct access to parking facilities and business entrances for commercial, private, and emergency response vehicles.

However, alley design features and the prevalence of parking facilities accessed through the alley may restrict the freight load/unload space in the alley. Future efforts should investigate how to better manage these infrastructures.

Recommended Citation:
Machado-León, Girón-Valderrama, G. del C., & Goodchild, A. (2020). Bringing Alleys to Light: An Urban Freight Infrastructure Viewpoint. Cities, 105. https://doi.org/10.1016/j.cities.2020.102847 

Freight and Transit Lane Study (Task Order 7)

The City of Seattle Department of Transportation (SDOT) engaged the Urban Freight Lab to conduct research on the impacts of a Freight and Transit-Only (FAT) Lane in place in January 2019. The research findings will be used to understand the FAT Lane’s performance towards achieving city goals and to guide the development of future FAT Lane projects.

The Seattle Freight Master Plan includes a FAT Lane strategy to reach the city’s economic goals:

  • (2) Economy – Provide a freight network that supports a thriving and diverse economy for Seattle and the region.
  • (2.4) Maintain and improve truck freight mobility and access between and within the city’s MICs and to the regional highway system
  • (2.4.2) Explore and test the use of truck-only lanes to improve freight mobility on city streets with high truck volumes

SDOT’s key research interests in this project are to:

  1. Document whether the FAT Lane’s benefits to truck drivers were strong enough to attract heavy freight vehicles from using other downtown streets. This will be measured by comparing truck volume on the Lane during implementation to volume after it was closed.
  2. Determine whether passenger cars followed the posted FAT Lane restrictions. This will be measured by documenting the number of cars violating the rule.
  3. Document transit use during the implementation period.

Background:

The Alaskan Way Viaduct, a major freight thoroughfare in Seattle, was closed on January 11, 2019 significantly reducing capacity in the already congested road network in Greater Downtown Seattle. To improve freight and transit access to commercial and industrial areas in the city, the City of Seattle Department of Transportation, in partnership with the WSDOT, temporarily installed two blocks of a Freight and Transit Lane on Alaskan Way.

The FAT Lane was in the curb lane only, on southbound Alaskan Way (at street level, not on the Viaduct). The 2-block segment is north of Little H on Alaskan Way, which provides access to Colorado and Alaskan Way. The FAT Lane supported Port of Seattle operations.

Research Tasks:

The following tasks will be completed by the Urban Freight Lab:

Task 1 – Research Scan

Subtasks:

  1. Conduct a short research scan of published reports that provide data-based evidence of the results of FAT Lane projects.
  2. Write a 2-3 page summary of the results of other FAT Lane projects

Task 2 – Analysis of video data

Subtasks:

  1. SDOT will provide video of the FAT Lane segment taken when the Lane was open and after it closed, to the UFL. The UFL will categorize and count vehicles in the lane as follows:
    • Transit/bus
    • Passenger/car
    • Truck/freight:
      1. Drayage with container
      2. Drayage without container
      3. All other trucks/freight vehicles. This category includes: delivery vans/trucks, construction and waste vehicles, and if readily apparent service commercial vehicles.
    • Other vehicles, e.g. those lacking differentiating features to categorize.
  2. UFL will analyze the count data and include key findings in the final report. The analysis will include:
    1. A comparison of truck volume on the Lane during implementation to the volume after it was closed. This may include time of day, day of week, or other factors.
    2. The number of passenger cars in the Lane during implementation. e.g. the number of violators.
    3. The UFL researchers will also explore whether comparing data collected in the Greater Downtown Cordon study to data collected in this study yields valid findings.
Paper

Analyzing the Effect of Autonomous Ridehailing on Transit Ridership: Competitor or Desirable First-/Last-Mile Connection?

 
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Publication: Transportation Research Record
Volume: 2675 (11)
Pages: 1154-1167
Publication Date: 2021
Summary:

Ridehailing services (e.g., Uber or Lyft) may serve as a substitute or a complement—or some combination thereof—to transit. Automation as an emerging technology is expected to further complicate the current complex relationship between transit and ridehailing. This paper aims to explore how US commuters’ stated willingness to ride transit is influenced by the price of ridehailing services and whether the service is provided by an autonomous vehicle. To that end, a stated preference survey was launched around the US to ask 1,500 commuters how they would choose their commute mode from among choices including their current mode and other conventional modes as well as asking them to choose between their current mode and an autonomous mode. Using a joint stated and revealed preference dataset, a mixed logit model was developed and analyzed.

Authors: Dr. Andisheh Ranjbari, Moein Khaloei, Ken Laberteaux, Don MacKenzie
Recommended Citation:
Khaloei, M., Ranjbari, A., Laberteaux, K., & MacKenzie, D. (2021). Analyzing the Effect of Autonomous Ridehailing on Transit Ridership: Competitor or Desirable First-/Last-Mile Connection? Transportation Research Record, 2675(11), 1154–1167. https://doi.org/10.1177/03611981211025278