Browsing by Subject "Autonomous vehicles"
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Item Advancing Social Equity with Shared Autonomous Vehicles: Literature Review, Practitioner Interviews, and Stated Preference Surveys(Center for Transportation Studies, University of Minnesota, 2022-01) Fan, Yingling; Wexler, Noah; Douma, Frank; Ryan, Galen; Hong, Chris; Li, Yanhua; Zhang, Zhi-LiThis report examines preferences and attitudes regarding the implementation and design of a hypothetical publicly-funded Shared Automated Vehicle (SAV) system in the Twin Cities metro area. We provide a brief literature review before delving into our main findings. First, we discuss a series of interviews in which officials at local planning agencies were asked about their vision for SAV in the Twin Cities. According to these interviews, SAV could be especially useful in solving first-and-last-mile problems and connecting with already existing transit and on-demand transportation infrastructure. We then analyze data sourced from an originally designed digital survey instrument implemented over social media in 2020 and specifically targeted at Twin Cities residents. Data from the survey emphasize that people who currently experience barriers to transportation are more likely to value SAV highly. The data also give insight into design considerations, emphasizing flexibility in payment and booking and the importance of security features. Finally, we examine data from a similar survey administered at the 2021 Minnesota State Fair, which we use to gauge preferences toward SAV among people living in the Twin Cities exurbs and Greater Minnesota.Item Anticipating land-use impacts of self-driving vehicles in the Austin, Texas, region(Journal of Transport and Land Use, 2020) Wellik, Tyler; Kockelman, KaraThis paper used an implementation of the land-use model SILO in Austin, Texas, over a 27-year period with an aim to understand the impacts of the full adoption of self-driving vehicles on the region's residential land use. SILO was integrated with MATSim for the Austin region. Land-use and travel results were generated for a business-as-usual case (BAU) of 0% self-driving or "autonomous" vehicles (AVs) over the model timeframe versus a scenario in which households’ value of travel time savings (VTTS) was reduced by 50% to reflect the travel-burden reductions of no longer having to drive. A third scenario was also compared and examined against BAU to understand the impacts of rising vehicle occupancy (VO) and/or higher roadway capacities due to dynamic ride-sharing (DRS) options in shared AV (SAV) fleets. Results suggested an 8.1% increase in average work-trip times when VTTS fell by 50% and VO remained unaffected (the 100% AV scenario) and a 33.3% increase in the number of households with "extreme work-trips" (over 1 hour, each way) in the final model year (versus BAU of 0% AVs). When VO was raised to 2.0 and VTTS fell instead by 25% (the "Hi-DRS" SAV scenario), average work-trip times increased by 3.5% and the number of households with "extreme work-trips" increased by 16.4% in the final model year (versus BAU of 0% AVs). The model also predicted 5.3% fewer households and 19.1% more available, developable land in the city of Austin in the 100% AV scenario in the final model year relative to the BAU scenario’s final year, with 5.6% more households and 10.2% less developable land outside the city. In addition, the model results predicted 5.6% fewer households and 62.9% more available developable land in the city of Austin in the Hi-DRS SAV scenario in the final model year relative to the BAU scenario’s final year, with 6.2% more households and 9.9% less developable land outside the city.Item Autonomous Vehicle Guidance Evaluation(Minnesota Department of Transportation, 1995-03) Shankwitz, Craig; Donath, MaxThis report provides an overview of autonomous vehicle technology, specifically focusing on sensing and control technologies. It resulted from safety issues at the Mn/ROAD high-load, low-volume pavement test facility. Appropriate technology helps ensure the safety of the truck driver that provides loads to the pavement and the safety of traffic on 1-94. Researchers currently are working to provide a semi tractor capable of driver-supervised autonomous operation at the Mn/ROAD facility. Such a driver-supervised system will allow the truck driver to monitor the operation of the automatic control system actively guiding the truck and will allow the driver to take control from the control computer when desired.Item Challenges and opportunities of autonomous vehicles to urban planning: Investigation into transit and parking(Center for Transportation Studies, University of Minnesota, 2019-10) Wu, Xinyi; Douma, Frank; Cao, JasonUsing a series of qualitative approaches, this report examines the potential impacts of autonomous vehicles (AV) on transit and parking systems. A literature review helped us identify three orders of general impacts caused by the development of AV, as well as their specific effects on transit and parking. Based on the results of the literature review, we organized two focus groups and held in-depth discussions regarding the impacts of AV with planning practitioners from the Minneapolis-St Paul metropolitan area. The analytical results showed that opinions differ regarding what AV's specific effects might look like. Nevertheless, all of the literature as well as participants of the focus groups agreed that AV will have significant impacts and corresponding planning policies need to be developed.Item Collision Avoidance: Smart Trucks on Rural Roads(Minnesota Department of Transportation, 1995-03) Shankwitz, Craig; Donath, MaxWith interest in collision avoidance technology for highway vehicles on the rise, this report presents an overview of current collision avoidance technology, the technical work required to bring these systems to a commercially viable product, and the societal issues that need addressing before wide-scale deployment can occur. Many questions remain about the benefits of deploying such systems, the costs, the effect of these systems on drivers, and the steps necessary to effectively regulate vehicles equipped with such systems. In addition to technical aspects, the report also discusses the issues that society will face during development and deployment of these systems, which may prove bigger impediments to deployment than technical issues. The report also recommends a research plan to perform fair, unbiased evaluations of emerging collision avoidance technology.Item Cost/Benefit Analysis of Fuel-Efficient Speed Control Using Signal Phasing and Timing (SPaT) Data: Evaluation for Future Connected Corridor Deployment(Minnesota Department of Transportation, 2023-03) Levin, Michael W.; Sun, Zongxuan; Wang, Shi’an; Sun, Wenbo; He, Suiyi; Suh, Bohoon; Zhao, Gaonan; Margolis, Jacob; Zamanpour, MaziarThe objective of this methodology is to refine the preliminary results from previous work (11% fuel savings for one vehicle, one intersection) to an entire corridor of SPaT signals, with different CV market penetration, and with driver awareness of fuel savings benefits. The research will proceed in three parts. First, several vehicles will be instrumented with DSRC receivers and GPS tracking to record SPaT data and the vehicle trajectories together. Offline, the project team will optimize the speed and powertrain control based on recorded SPaT data, using the recorded vehicle trajectories to identify the constraints of traffic flow. A living lab consisting of a GM car engine loaded by a transient hydrostatic dynamometer will be used to measure the fuel consumption with and without speed control. Second, the project team will conduct traffic flow simulations to study the impacts of higher market penetration on the overall fuel benefits, including the benefits to legacy vehicles which unintentionally use SPaT based speed controls by following CVs. Third, network models will be used to predict changes in route choices as drivers recognize the benefits of fuel savings in the route utility. The numerical predictions of fuel savings will be combined into cost/benefit analyses to inform MnDOT on the future deployment of SPaT on other corridors.Item Designing an Autonomous Service to Cover Transit’s Last Mile in Low-Density Areas(Minnesota Department of Transportation, 2024-03) Khani, Alireza; Aalipour, Ali; Kumar, PrameshPublic transportation provides a safe, convenient, affordable, and environmentally friendly mobility service. However, due to its fixed routes and limited network coverage, it is sometimes difficult or impossible for passengers to walk from a transit stop to their destination. This inaccessibility problem is also known as the "transit last-mile connectivity problem." Such a lack of connectivity forces travelers to drive, thereby increasing vehicle miles traveled (VMT) on roads. The autonomous mobility-on-demand (AMoD) service, with characteristics such as quick fleet repositioning and demand responsiveness, as well as lower operational cost due to the elimination of operators' wages, has the potential to provide last-mile coverage where fixed-route transit can only provide limited service. This study presents research on designing an AMoD service to solve the transit last-mile problem in Greater Minnesota. After selection of the Miller Hill Mall (MMH) area in Duluth, MN, as the case study site, analysis on local transit services and demand data show that passengers may have to spend significant time walking and cross multiple streets to access stores from transit stops. To address this issue, an AMoD system for last-mile service was designed and integrated with the fixed route transit service. Novel mathematical models and AMoD control algorithms were developed, and simulation experiments were conducted for evaluation of the AMoD service. Simulation results showed that the AMoD service can improve transit quality of service and attract more riders to use transit to the MHM area, and therefore reduce the VMT in the region. These findings were consistent with the literature in that mode choice and first-/last-mile access were highly interdependent and AMoD can improve transit quality of service and reduce VMT. Research on riders' perception of AMoD service and field testing of the AMoD system using the developed models and algorithms are recommended to help agencies prepare for application of AMoD system in the region.Item Equity Issues of Self-Driving Vehicles (Research Brief)(Center for Transportation Studies, University of Minnesota, 2018-06) Transportation Policy and Economic Competitiveness ProgramThis two-page research brief summarizes TPEC work regarding equity in the development and implementation of self-driving vehicles. It corresponds to Self-Driving Vehicle Task Force Write-up: Issues, Opportunities, and Next Steps.Item Fostering Social Equity with Automated Vehicles (Research Brief)(Center for Transportation Studies, University of Minnesota, 2022-03) Center for Transportation StudiesThis research brief summarizes the highlights and findings for research report CTS 22-01, Advancing Social Equity with Shared Autonomous Vehicles: Literature Review, Practitioner Interviews, and Stated Preference Surveys. This research was funded as part of a National Science Foundation (NSF) Smart and Connected Communities grant, Leveraging Autonomous Shared Vehicles for Greater Community Health, Equity, Livability, and Prosperity (HELP).Item Future Streets: Leveraging Autonomous Shared Vehicles for Greater Community Health, Equity, Livability and Prosperity(2021-08) Fisher, TomThis publication shows the work that the staff and students of the Minnesota Design Center have done to illustrate the nature of AV-ready alleys, local streets, collector streets, and arterial streets. With each street type, an overview provides the existing condition and its AV alternative, with calculations related to planting, stormwater retention, heat island effects, and material costs. There are cross-sections through each street type to indicate the below grade conditions of AV-ready streets and how they compare to now.Item Gauging the Impacts: Self-Driving Vehicles (Research Brief)(Center for Transportation Studies, University of Minnesota, 2017-04) Transportation Policy and Economic Competitiveness ProgramThis two-page research brief summarizes the 2014 conference Automated Vehicles: The Legal and Policy Road Ahead and a series of 2016 roundtables about the impacts of the digital infrastructure and self-driving vehicles.Item Grand Rapids GoMARTI Self-Driving Shuttle Pilot Program(Minnesota Department of Transportation, 2024-07) Douma, Frank; Weiner, EvelynIn fall 2022, a first-of-its-kind connected and automated vehicle (CAV) pilot program called goMARTI (Minnesota's Autonomous Rural Transit Initiative) was launched as a collaborative effort between numerous partners. The 18-month pilot offers free, on-demand rides to area residents and visitors using five autonomous shuttle vans (including three wheelchair-accessible vans) at 70 drop-off and pick-up points within a 17-square-mile area. In this project, researchers documented lessons learned from the pilot, which included exploring the recent history of institutional and community engagement efforts regarding transportation in Itasca County and Grand Rapids, as well as the innovations and collaborations that took place to make the pilot's implementation possible.Item Identifying the combined effect of shared autonomous vehicles and congestion pricing on regional job accessibility(Journal of Transport and Land Use, 2020) Zhong, Shaopeng; Cheng, Rong; Li, Xufeng; Wang, Zhong; Jiang, YuMost of the existing research on shared autonomous vehicles (SAVs) and road congestion pricing have studied the short-term impact on traffic flow. These types of studies focused on the influences on mobility and ignored the long-term impacts on regional job accessibility. Given this, from the perspective of land use and transportation integration, this study explored the long-term effects of SAVs and cordon-based congestion pricing on regional land use, transportation, and job accessibility. The contributions of this study have been summarized by the following three purposes. First, to the best of the authors' knowledge, this study was the first attempt to identify the long-term impact of the combination of these two technologies on regional job accessibility. Second, compared to the previous research methodology, this study adopted the land use and transportation integrated model (TRANUS model) and scenario planning to ensure the comprehensiveness and validity of the results. Third, this study analyzed the spatial heterogeneity of the impact of the combination of the two technologies on regional job accessibility in different areas with different built-environment attributes. To realize this purpose, this study quantitatively classified traffic analysis zones (TAZs) using data mining technology, i.e., factor analysis and clustering analysis. Results showed that the introduction of SAVs will contribute to job and population development in the charging zone and reduce the negative effect of road congestion pricing. From the perspective of reducing the average travel time between TAZs, the best strategy will be to implement SAVs alone, followed by integrated use of SAVs and road congestion pricing, while the worst strategy will be to implement the cordon-based congestion pricing policy alone. By comparison, from the perspective of improving regional job accessibility, the effect of introducing SAVs was better than that of road congestion pricing, while the combination of these two technologies was not superior to implementing SAVs alone.Item Improving intersection safety through variable speed limits for connected vehicles(Center for Transportation Studies, University of Minnesota, 2019-05) Levin, Michael; Chen, Rongsheng; Liao, Chen-Fu; Zhang, TabAutonomous vehicles create new opportunities for innovative intelligent traffic systems. Variable speed limits, which is a speed management systems that can adjust the speed limit according to traffic condition or predefined speed control algorithm on different road segments, can be better implemented with the cooperation of autonomous vehicles. These compliant vehicles can automatically follow speed limits. However, non-compliant vehicles will attempt to pass the moving bottleneck created by the compliant vehicle. This project builds a multi-class cell transmission model to represent the relation between traffic flow parameters. This model can calculate flows of both compliant and non-compliant vehicles. An algorithm is proposed to calculate variable speed limits for each cell of the cell transmission model. This control algorithm is designed to reduce the stop-and-go behavior of vehicles at traffic signals. Simulation is used to test the effects of VSLs on an example network. The result shows that VSL is effective at reducing the energy consumption of the whole system and reduce the likelihood of crash occurrence.Item Influence of Autonomous and Partially Autonomous Vehicles on Minnesota Roads(Minnesota Department of Transportation, 2023-05) Espindola, Andre; Alexander, Lee; Rajamani, RajeshThis project focuses on experimental tests of the performance characteristics of autonomous vehicles (AVs) on highways and local roads in Minnesota. The project provides detailed data characterizing AV performance, which in turn can be used to inform the transportation community on implications for infrastructure maintenance, winter road maintenance, work zone guidelines, safety, and traffic capacity. The experimental work presented here makes use of a new autonomous vehicle purchased by the Center for Transportation Studies at the University of Minnesota. The key aspects of the autonomous functions of the vehicle studied in this project include winter performance and implications for road maintenance, characterization of the driving performance of the AV and its likely influence on safety, traffic flow and fuel economy, and the ability of the AV to handle work zones and the implications on changes needed to the guidelines for work zones. The project documents the major challenges and obstacles ahead in the way of true autonomy on Minnesota roads, but also outlines further areas for research with which it will be possible to facilitate the improvement of the capabilities of autonomous vehicles in Minnesota in the future.Item Integration of Microsimulation and Optimized Autonomous Intersection Management(2018-12) Olsson, JackAutonomous intersection management (AIM) is a type of intersection control for autonomous vehicles which eliminates the need for a traffic signal by using vehicle-to-infrastructure communication. Vehicles communicate information to an intersection manager which determines vehicle ordering and spacing such that vehicles can pass safely through the intersection. Reservation-based AIM, which give vehicles space-time path reservations through an intersection, has the potential to greatly increase the capacity of intersections by allowing an intersection controller to optimize all vehicle paths. A mixed-integer linear program is proposed which gives more flexibility in optimizing vehicle acceleration. This model was integrated with the microsimulation software Aimsun and scenarios were simulated which included fluctuating vehicle demands, altering vehicle speeds, and modifying spacing between vehicles. The results indicate that the model proposed in this study can reduce delay and increase average speed experienced by vehicles compared to the existing reservation-based intersection control formulations and conventional signal controls.Item Planning for Disruption: Connected and Autonomous Vehicles(Center for Transportation Studies, University of Minnesota, 2019-09) Burga, Fernando; Fisher, TomThe future of transportation is inseparable from the future of work. Over the last century, transportation has focused on moving people and goods, but work in the 21st century has started to change dramatically due to vehicle automation, changing consumer patterns, and the rise of virtual retail. These factors will bring profound changes in transportation, infrastructure, and access to resources in the city, including housing, food, public spaces, and labor opportunities. This research project investigated the implications of the forthcoming changes in transportation, mobility, and the nature of work. It focused on the impact of vehicle automation on jobs access and explored the tensions that arise as new vehicle automation technologies are introduced into the streets of neighborhoods with historically disadvantaged residents.Item Pressure-based dispatch for shared autonomous vehicles(Center for Transportation Studies, University of Minnesota, 2019-08) Levin, Michael; Kang, DiShared autonomous vehicle (SAV) technology is rapidly maturing, with two companies (Uber and Waymo) already testing SAV services in cities in the US. Due to the point-to-point service and lack of a driver, SAV service costs could be similar to that of personal vehicles, resulting in major mode choice changes for daily travel. A major issue for SAV operators is the SAV dispatch problem, i.e., how to optimally assign vehicles to waiting passengers. SAV dispatch is essentially a vehicle routing problem, which is NP-hard, and is complicated by fleets measured in thousands of vehicles in typical cities. Previous studies have attempted to quantify the number of passengers served per SAV using agent-based simulation studies on realistic networks, with a variety of results that highly depend on the heuristic chosen for SAV dispatch. Ideally, the optimal SAV dispatch strategy would serve as many passengers as any other policy. This project created a max-pressure dispatch policy, which was analytically proven by showing stability in the number of unserved passengers through a Lyapunov function. Essentially, the work analytically compared the serviceable demand from the max-pressure dispatch to the demand that could be served by any other dispatch policy. The max-pressure policy relied on a planning horizon; as the horizon grows to infinity, the policy becomes arbitrarily close to any sequence of SAV movements that can serve given demand rates.Item Self-Driving Vehicle Task Force Write-up: Issues, Opportunities, and Next Steps(Transportation Policy and Economic Competitiveness Program, University of Minnesota, 2017-06) State and Local Policy Program, Humphrey School of Public AffairsThis report summarizes activities of the Self-Driving Vehicle Task Force, including issues, opportunities, and next steps. The appendix contains a Matrix of Users chart designed to cross-compare geography, barriers to participation, and the potential forms of self-driving transportation that may be implemented in Minnesota.Item Strategic Visioning Workshop for Automated Vehicles in Minnesota: Summary Report(Center for Transportation Studies, University of Minnesota, 2018) Center for Transportation StudiesThis report summarizes a strategic visioning workshop held June 25-26, 2018, in Minneapolis that helped to define a framework for deploying AV technologies in Minnesota.