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on Transport Economics |
| By: | Hardman, Scott; Garas, Dahlia; Allen, Jeff; Axsen, Jonn; Beard, George; Dütschke, Elisabeth; Daina, Nicolò; Figenbaum, Erik; Jochem, Patrick; Nicholas, Michael; Plötz, Patrick; Refa, Nazir; Sovacool, Benjamin; Sperling, Daniel; Sprei, Frances; Tal, Gil |
| Abstract: | Key Takeaways 1. The electrification of passenger vehicles should be one part of a city’s transportation plan. Shifting from internal combustion engine vehicles to plug-in electric vehicles (PEVs) can improve urban air quality, reduce greenhouse gas emissions, and reduce energy consumption. 2. Recent studies show that electric vehicle awareness is low even in mature markets; cities should promote electric vehicles to residents by leveraging existing promotional campaigns. 3. Various financial and non-financial incentives can effectively encourage electric vehicle uptake, including: free, discounted, or preferential-location parking; free or reduced road and bridge tolls; and allowing electric vehicles to drive in bus or carpool lanes. 4. Several cities are restricting or planning to restrict the access that internal combustion engine vehicles (ICEVs) have to certain areas. If these restrictions apply to most (or all) passenger ICEVs, they can promote PEV purchase and use in cities. 5. Infrastructure development in cities should follow the same fundamental approach as that used outside of cities. The priority should be ensuring that PEV owners and prospective PEV buyers have access to charging at or near home. Workplace and public charging should be developed for those who cannot access charging at or near home. 6. Cities should be strategic in their approach, first identifying the goals they want to achieve, and then exploring what steps they can take to meet these goals. The steps available will likely differ between cities due to the different ways in which roads, parking, and any other vehicle infrastructure is governed. |
| Keywords: | Engineering, Social and Behavioral Sciences |
| Date: | 2020–01–01 |
| URL: | http://d.repec.org/n?u=RePEc:cdl:itsdav:qt8q2917sh&r=all |
| By: | Perumal, S.S.G.; Dollevoet, T.A.B.; Huisman, D.; Lusby, R.M.; Larsen, J.; Riis, M. |
| Abstract: | The use of electric buses is expected to rise due to its environmental benefits. However, electric vehicles are less exible than conventional diesel buses due to their limited driving range and longer recharging times. Therefore, scheduling electric vehicles adds further operational dificulties. Additionally, various labor regulations challenge public transport companies to find a cost-effcient crew schedule. Vehicle and crew scheduling problems essentially define the cost of operations. In practice, these two problems are often solved sequentially. In this paper, we introduce the integrated electric vehicle and crew scheduling problem (E-VCSP). Given a set of timetabled trips and recharging stations, the E-VCSP is concerned with finding vehicle and crew schedules that cover the timetabled trips and satisfy operational constraints, such as limited driving range of electric vehicles and labor regulations for the crew while minimizing total operational cost. An adaptive large neighborhood search that utilizes branch-and-price heuristics is proposed to tackle the E-VCSP. The proposed method is tested on real-life instances from public transport companies in Denmark and Sweden that contain up to 1,109 timetabled trips. The heuristic approach provides evidence of improving efficiency of transport systems when the electric vehicle and crew scheduling aspects are considered simultaneously. By comparing to the traditional sequential approach, the heuristic finds improvements in the range of 1.17-4.37% on average. A sensitivity analysis of the electric bus technology is carried out to indicate its implications for the crew schedule and the total operational cost. The analysis shows that the operational cost decreases with increasing driving range (120 to 250 kilometers) of electric vehicles. |
| Keywords: | Public Transportation, Integrated Planning, Column Generation, Adaptive Large Neighborhood Search |
| Date: | 2020–01–01 |
| URL: | http://d.repec.org/n?u=RePEc:ems:eureir:123963&r=all |
| By: | Wu, Guoyuan; Zhao, Zhouqiao; Wang, Ziran; Barth, Matthew J. |
| Abstract: | With on-board sensors such as camera, radar, and Lidar, connected and automated vehicles (CAVs) can sense the surrounding environment and be driven autonomously and safely by themselves without colliding into other objects on the road. CAVs are also able to communicate with each other and roadside infrastructure via vehicle-to-vehicle and vehicle-to-infrastructure communications, respectively, sharing information on the vehicles’ states, signal phase and timing (SPaT) information, enabling CAVs to make decisions in a collaborative manner. As a typical scenario, ramp control attracts wide attention due to the concerns of safety and mobility in the merging area. In particular, if the line-of-the-sight is blocked (because of grade separation), then neither mainline vehicles nor on-ramp vehicles may well adapt their own dynamics to perform smoothed merging maneuvers. This may lead to speed fluctuations or even shockwave propagating upstream traffic along the corridor, thus potentially increasing the traffic delays and excessive energy consumption. In this project, the research team proposed a hierarchical ramp merging system that not only allowed microscopic cooperative maneuvers for connected and automated electric vehicles on the ramp to merge into mainline traffic flow, but also had controllability of ramp inflow rate, which enabled macroscopic traffic flow control. A centralized optimal control-based approach was proposed to both smooth the merging flow and improve the system-wide mobility of the network. Linear quadratic trackers in both finite horizon and receding horizon forms were developed to solve the optimization problem in terms of path planning and sequence determination, and a microscopic electric vehicle (EV) energy consumption model was applied to estimate the energy consumption. The simulation results confirmed that under the regulated inflow rate, the proposed system was able to avoid potential traffic congestion and improve the mobility (in terms of average speed) as much as 115%, compared to the conventional ramp metering and the ramp without any control approach. Interestingly, for EVs (connected and automated EVs in this study), the improved mobility may not necessarily result in the reduction of energy consumption. The “sweet spot” of average speed ranges from 27–34 mph for the EV models in this study. View the NCST Project Webpage |
| Keywords: | Engineering, Connected vehicles, automated vehicles, ramp merging management, optimal control |
| Date: | 2020–01–01 |
| URL: | http://d.repec.org/n?u=RePEc:cdl:itsdav:qt63r0f737&r=all |
| By: | Shaheen, Susan; Cohen, Adam |
| Abstract: | Technology is changing the way we move and reshaping cities and society. Shared and on-demand mobility represent notable transportation shifts in the 21st century. In recent years, mobility on demand (MOD)—where consumers access mobility, goods, and services on-demand by dispatching shared modes, courier services, public transport, and other innovative strategies—has grown rapidly due to technological advancements; changing consumer preferences; and a range of economic, environmental, and social factors. New attitudes toward sharing, MOD, and mobility as a service (MaaS) are changing traveler behavior and creating new opportunities and challenges for public transportation. This chapter discusses similarities and differences between the evolving concepts of MaaS and MOD. Next, it characterizes the range of existing public transit and MOD service models and enabling partnerships. The chapter also explores emerging trends impacting public transportation. While vehicle automation could result in greater public transit competition in the future, it could also foster new opportunities for transit enhancements (e.g., microtransit services, first- and last-mile connections, reduced operating costs). The chapter concludes with a discussion of how MOD/MaaS partnerships and automation could enable the public transit industry to reinvent itself, making it more attractive and competitive with private vehicle ownership and use. |
| Keywords: | Engineering, Benchmarking, Impacts, Mobility as a service, Mobility on demand, Public policy, Public transit, Public–private partnerships, Shared mobility, Travel behavior, Vehicle automation |
| Date: | 2020–01–01 |
| URL: | http://d.repec.org/n?u=RePEc:cdl:itsrrp:qt5030f0cd&r=all |
| By: | Eleftheria Kontou; Noreen C. McDonald |
| Abstract: | Improving road safety and setting targets for reducing traffic-related crashes and deaths are highlighted as part of the United Nation's sustainable development goals and vision zero efforts around the globe. The advent of transportation network companies, such as ridesourcing, expands mobility options in cities and may impact road safety outcomes. In this study, we analyze the effects of ridesourcing use on road crashes, injuries, fatalities, and driving while intoxicated (DWI) offenses in Travis County Texas. Our approach leverages real-time ridesourcing volume to explain variation in road safety outcomes. Spatial panel data models with fixed effects are deployed to examine whether the use of ridesourcing is significantly associated with road crashes and other safety metrics. Our results suggest that for a 10% increase in ridesourcing trips, we expect a 0.12% decrease in road crashes (p |
| Date: | 2020–01 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:2001.03461&r=all |
| By: | Hao, Peng; Wei, Zhensong; Bai, Zhengwei; Barth, Matthew J. |
| Abstract: | The Eco-Approach and Departure (EAD) application has been proved to be environmentally efficient for a Connected and Automated Vehicles (CAVs) system. In the real-world traffic, traffic conditions and signal timings are usually dynamic and uncertain due to mixed vehicle types, various driving behaviors and limited sensing range, which is challenging in EAD development. This research proposes an adaptive strategy for connected eco-driving towards a signalized intersection under real world conditions. Stochastic graph models are built to link the vehicle and external (e.g., traffic, signal) data and dynamic programing is applied to identify the optimal speed for each vehicle-state efficiently. From energy perspective, adaptive strategy using traffic data could double the effective sensor range in eco-driving. A hybrid reinforcement learning framework is also developed for EAD in mixed traffic condition using both short-term benefit and long-term benefit as the action reward. Micro-simulation is conducted in Unity to validate the method, showing over 20% energy saving. View the NCST Project Webpage |
| Keywords: | Engineering, Eco-Approach and Departure, Connected Vehicles, reinforcement learning, energy, mixed traffic |
| Date: | 2020–01–01 |
| URL: | http://d.repec.org/n?u=RePEc:cdl:itsdav:qt2fv5063b&r=all |
| By: | Fitch, Dillon; Carlen, Jane; Handy, Susan |
| Abstract: | In this study, researchers use survey data to analyze bicycling comfort and its relationship with socio-demographics, bicycling attitudes, and bicycling behavior. An existing survey of students, faculty, and staff at UC Davis (n=3089) who rated video clips of bicycling environments based on their perceived comfort as a part of the UC Davis annual Campus Travel Survey (CTS) is used. The video clips come from a variety of urban and semi-rural roads (designated California state highways) around the San Francisco Bay Area where bicycling rates vary. Results indicate considerable effects of socio-demographics and attitudes on absolute video ratings, but relative agreement about which videos are most comfortable and uncomfortable across population segments. In addition, presence of bike infrastructure and low speed roads are the strongest video factors generating more comfortable ratings. However, the results suggest that even the best designed on-road bike facilities are unlikely to provide a comfortable bicycling environment for those without a predisposition to bicycle. This suggests that protected and separated bike facilities may be required for many people to consider bicycling. Nonetheless, the results provide guidance for improving roads with on-street bike facilities where protected or separated facilities may not be suitable. View the NCST Project Webpage |
| Keywords: | Engineering, Social and Behavioral Sciences, Cycling, active travel, infrastructure |
| Date: | 2020–01–01 |
| URL: | http://d.repec.org/n?u=RePEc:cdl:itsdav:qt7jn8h79x&r=all |
| By: | Polinder, G.-J.; Schmidt, M.E.; Huisman, D. |
| Abstract: | In research and practice, public transportation planning is executed in a series of steps, which are often divided into the strategic, the tactical, and the operational planning phase. Timetables are normally designed in the tactical phase, taking into account a given line plan, safety restrictions arising from infrastructural constraints, as well as regularity requirements and bounds on transfer times. In this paper, however, we propose a timetabling approach that is aimed at decision making in the strategic phase of public transportation planning and to determine an outline of a timetable that is good from the passengers’ perspective. Instead of including explicit synchronization constraints between train runs (as most timetabling models do), we include the adaption time (waiting time at the origin station) in the objective function to ensure regular connections between passengers’ origins and destinations. We model the problem as a mixed integer quadratic program and linearise it. Furthermore we propose a heuristic to generate starting solutions. We illustrate the type of solutions found by our approach on two case studies based on the Dutch railway network and analyse trade-offs that are made to balance dwell times and regularity of trains. |
| Keywords: | public transportation planning, strategic timetabling, integration of timetabling and passenger routing |
| Date: | 2020–01–28 |
| URL: | http://d.repec.org/n?u=RePEc:ems:eureri:123973&r=all |
| By: | Young, Mischa; Farber, Steven |
| Abstract: | Convenience and low prices have enabled ride-hailing companies, such as Uber and Lyft, to position themselves amongst the most valuable companies within the transportation sector. They now account for the lion share of activities in the platform economy and play an increasing role within our cities. Despite this, very little is known about the type of people that use them, nor the purpose and timing of trips. In addition to this, their effect on other modes, such as taxis and public transit, remains, for the most part, widely unexplored. By comparing the socioeconomic and trip characteristics of ride-hailing users to that of other mode users, we find ride-hailing to be a wealthy younger generation phenomenon. While our results show that ride-hailing is too minute and inconsequential to influence the ridership level of other more substantial modes of travel overall, when considering specific market segments, the rise of ride-hailing corresponds to a significant decrease in taxi ridership and a rise in active modes of travel. Moreover, due to the specific age, timing, and purpose of our subsample, we believe that ride-hailing may effectively reduce drunk-driving, and are convinced that as this mode increases in importance in the future, it will have a much more pronounced effect on the level of ridership of other modes as well. |
| Date: | 2019–01–01 |
| URL: | http://d.repec.org/n?u=RePEc:osf:osfxxx:x7ryj&r=all |
| By: | Planing, Patrick; Pinar, Yasemin |
| Abstract: | Due to rising urbanization, cities around the world are struggling with mobility and infrastructure problems. Electric vertical takeoff and landing (eVTOL) aircraft, or short air taxis, can potentially offer a local emission-free and infrastructure conserving solution to these problems. The German Start-Up Volocopter has already proven the technical feasibility in their Demo Flight in Dubai 2017. The technology develops increasingly fast towards market readiness. Even though there are technical and legal challenges, however, the success of air taxis will depend upon the widespread acceptance of this service by consumers and society. The aim of this study is to understand consumers’ attitudes towards the technology and the factors that lead to either acceptance or rejection of air taxis. |
| Date: | 2019–12–03 |
| URL: | http://d.repec.org/n?u=RePEc:osf:osfxxx:rqgpc&r=all |