A dynamic ridesharing dispatch and idle vehicle repositioning strategy with integrated transit transfers

We propose a ridesharing strategy with integrated transit in which a private on-demand mobility service operator may drop off a passenger directly door-to-door, commit to dropping them at a transit station or picking up from a transit station, or to both pickup and drop off at two different stations with different vehicles. We study the effectiveness of online solution algorithms for this proposed strategy. Queueing-theoretic vehicle dispatch and idle vehicle relocation algorithms are customized for the problem. Several experiments are conducted first with a synthetic instance to design and test the effectiveness of this integrated solution method, the influence of different model parameters, and measure the benefit of such cooperation. Results suggest that rideshare vehicle travel time can drop by 40-60% consistently while passenger journey times can be reduced by 50-60% when demand is high. A case study of Long Island commuters to New York City (NYC) suggests having the proposed operating strategy can substantially cut user journey times and operating costs by up to 54% and 60% each for a range of 10-30 taxis initiated per zone. This result shows that there are settings where such service is highly warranted

Carbon Free Boston: Social equity report 2019

OVERVIEW: In January 2019, the Boston Green Ribbon Commission released its Carbon Free Boston: Summary Report, identifying potential options for the City of Boston to meet its goal of becoming carbon neutral by 2050. The report found that reaching carbon neutrality by 2050 requires three mutually-reinforcing strategies in key sectors: 1) deepen energy efficiency while reducing energy demand, 2) electrify activity to the fullest practical extent, and 3) use fuels and electricity that are 100 percent free of greenhouse gases (GHGs). The Summary Report detailed the ways in which these technical strategies will transform Boston’s physical infrastructure, including its buildings, energy supply, transportation, and waste management systems. The Summary Report also highlighted that it is how these strategies are designed and implemented that matter most in ensuring an effective and equitable transition to carbon neutrality. Equity concerns exist for every option the City has to reduce GHG emissions. The services provided by each sector are not experienced equally across Boston’s communities. Low-income families and families of color are more likely to live in residences that are in poor physical condition, leading to high utility bills, unsafe and unhealthy indoor environments, and high GHG emissions.1 Those same families face greater exposure to harmful outdoor air pollution compared to others. The access and reliability of public transportation is disproportionately worse in neighborhoods with large populations of people of color, and large swaths of vulnerable neighborhoods, from East Boston to Mattapan, do not have ready access to the city’s bike network. Income inequality is a growing national issue and is particularly acute in Boston, which consistently ranks among the highest US cities in regards to income disparities. With the release of Imagine Boston 2030, Mayor Walsh committed to make Boston more equitable, affordable, connected, and resilient. The Summary Report outlined the broad strokes of how action to reach carbon neutrality intersects with equity. A just transition to carbon neutrality improves environmental quality for all Bostonians, prioritizes socially vulnerable populations, seeks to redress current and past injustice, and creates economic and social opportunities for all. This Carbon Free Boston: Social Equity Report provides a deeper equity context for Carbon Free Boston as a whole, and for each strategy area, by demonstrating how inequitable and unjust the playing field is for socially vulnerable Bostonians and why equity must be integrated into policy design and implementation. This report summarizes the current landscape of climate action work for each strategy area and evaluates how it currently impacts inequity. Finally, this report provides guidance to the City and partners on how to do better; it lays out the attributes of an equitable approach to carbon neutrality, framed around three guiding principles: 1) plan carefully to avoid unintended consequences, 2) be intentional in design through a clear equity lens, and 3) practice inclusivity from start to finish

On the interaction between Autonomous Mobility-on-Demand systems and the power network: models and coordination algorithms

We study the interaction between a fleet of electric, self-driving vehicles servicing on-demand transportation requests (referred to as Autonomous Mobility-on-Demand, or AMoD, system) and the electric power network. We propose a model that captures the coupling between the two systems stemming from the vehicles' charging requirements and captures time-varying customer demand and power generation costs, road congestion, battery depreciation, and power transmission and distribution constraints. We then leverage the model to jointly optimize the operation of both systems. We devise an algorithmic procedure to losslessly reduce the problem size by bundling customer requests, allowing it to be efficiently solved by off-the-shelf linear programming solvers. Next, we show that the socially optimal solution to the joint problem can be enforced as a general equilibrium, and we provide a dual decomposition algorithm that allows self-interested agents to compute the market clearing prices without sharing private information. We assess the performance of the mode by studying a hypothetical AMoD system in Dallas-Fort Worth and its impact on the Texas power network. Lack of coordination between the AMoD system and the power network can cause a 4.4% increase in the price of electricity in Dallas-Fort Worth; conversely, coordination between the AMoD system and the power network could reduce electricity expenditure compared to the case where no cars are present (despite the increased demand for electricity) and yield savings of up $147M/year. Finally, we provide a receding-horizon implementation and assess its performance with agent-based simulations. Collectively, the results of this paper provide a first-of-a-kind characterization of the interaction between electric-powered AMoD systems and the power network, and shed additional light on the economic and societal value of AMoD.Comment: Extended version of the paper presented at Robotics: Science and Systems XIV and accepted by TCNS. In Version 4, the body of the paper is largely rewritten for clarity and consistency, and new numerical simulations are presented. All source code is available (MIT) at https://dx.doi.org/10.5281/zenodo.324165