Roadmap for free-floating bikeshare research and practice in North America

ABSTRACT

The deployment of smartphone-operated, non-station-based bicycle fleets (“dockless” or “free-floating” bikeshare) represents a new generation of bikesharing. Users locate bikes in these free-floating systems using Global Positioning Systems (GPS) and lock bikes in place at their destinations. In this paper, we review current free-floating bikesharing systems in North America and discuss priorities for future research and practice. Since launching in 2017, free-floating bikeshare has expanded rapidly to encompass 200+ systems operating 40,000+ bikes within 150+ cities. In contrast with previous systems, free-floating systems operate almost exclusively using commercial “for-profit” models, amidst concerns of financial sustainability. Governance for these systems is in early stages and can include operating fees, fleet size caps, safety requirements, parking restrictions, data sharing, and equity obligations. We identify research and practice gaps within the themes of usage, equity, sharing resources, business model, and context. While some existing bikesharing literature translates to free-floating systems, novel topics arise due to the ubiquity, fluidity, and business models of these new systems. Systems have numerous obstacles to overcome for long-term sustainability, including barriers common to station-based systems: limited supportive infrastructure, equity, theft or vandalism, and funding. Other unique obstacles arise in free-floating bikeshare around parking, sidewalk right of ways, varied bicycle types, and data sharing. This review offers background in and critical reflection on the rapidly evolving free-floating bikeshare landscape, including priorities for future research and practice. If concerns can be overcome, free-floating bikeshare may provide unprecedented opportunities to bypass congested streets, encourage physical activity, and support urban sustainability.     

Implementing Road User Charging: The Lessons Learnt from Hong Kong,Cambridge and Central London

Abstract

This paper studies the possibility of increasing shipping of fruit and vegetables from Almería (southeast of Spain) to Port Vendres‐Perpignan (southeast of France). Almería is one of the areas of vegetables production largest in the world and Perpignan is one of the most important customers of Almería. After analysing the potential volume of shipping, we estimate a mode choice model which allows us to study the sensitivity of final clients (horticultural operators) to future change in the variables which condition the choice between transport by sea or by land. This will also help us to calculate the market share of each system as a function of foreseeable change in the variables.     

Modeling residential sorting effects to understand the impact of the built environment on commute mode choice

This paper presents an examination of the significance of residential sorting or self selection effects in understanding the impacts of the built environment on travel choices. Land use and transportation system attributes are often treated as exogenous variables in models of travel behavior. Such models ignore the potential self selection processes that may be at play wherein households and individuals choose to locate in areas or built environments that are consistent with their lifestyle and transportation preferences, attitudes, and values. In this paper, a simultaneous model of residential location choice and commute mode choice that accounts for both observed and unobserved taste variations that may contribute to residential self selection is estimated on a survey sample extracted from the 2000 San Francisco Bay Area household travel survey. Model results show that both observed and unobserved residential self selection effects do exist; however, even after accounting for these effects, it is found that built environment attributes can indeed significantly impact commute mode choice behavior. The paper concludes with a discussion of the implications of the model findings for policy planning.

Vehicle Dynamics Estimation Using Kalman Filters

This paper deals with the application of stochastic state estimators in vehicle dynamics control. It is often unrealistic to assume that all vehicle states and the disturbances acting on it can be measured. System states that cannot be measured directly, can be estimated by a Kalman Filter. The idea of the Kalman filter is to implement a model of the real system in an on-board computer in parallel with the system itself. This paper will give 3 examples of this principle applied to automotive systems.     

2006年美国进口车新技术一览(上)

在美国,所有进口汽车制造商都推出了2006款新车型．其中包括两种混合动力车。这些进口车也将能达到美国国产车的维修技术要求,如按照SAEJ2534标准的车载电脑通用再编程技术。本田、日产、丰田以及马自达和宝马汽车都可通过网络实现这一功能。本文将介绍一些新的技术。     

汽车改装潮流中维修店的营利机会(下)

为提高汽车性能而进行的改装工作,可以为独立汽修店提供一些营利的机会,但许多汽修厂还没有意识到这一点。不过,与通常的维修业务不同的是,进行汽车改装所产生的后果,车主必须愿意承担至少一部分的责任。     

What do commuters think travel time reliability is worth? Calculating economic value of reducing the frequency and extent of unexpected delays

The measurement of transportation system reliability has become one of the central topics of travel demand studies. A growing literature concerns the measurement of value of travel time reliability which provides a monetary cost of avoiding unpredictable travel time. The goal of this study is to measure commuters’ sensitivities to travel time reliability and their willingness to pay (WTP) to avoid unreliable routes. The preferences are elicited through a pivoted stated preference survey technique. To circumvent the issue of presenting numerical distributions and statistical terms to day-to-day commuters, we use the frequency of delay days as a means of measuring traveler’s sensitivities to travel time reliability. The advantage of using simplified measures to elicit traveler preferences for travel time reliability is that these methods simply compare days with high delay to days with usual travel time. It was found that travelers are not only averse to the amount of unexpected delay but also to the frequency of days with unexpected delays. The paper presents WTP findings for three measures: travel time, frequency embedded travel time, and travel time reliability. The ‘reliability’ increase in WTP for travel time is found to be nearly proportional to the frequency of experiencing unexpected delays. For example, the WTP for mean travel time is calculated at $6.98/h; however, reliability adds $3.27 (about 50 % of $6.98) to avoid unexpected delays ‘5 out of 10 days’. The results of the study would provide valuable inputs to cost-benefit analyses and traffic and revenue studies required for road tolling investment projects.     

Some thoughts on competitive tendering in local bus operations

Abstract

This article is derived from a report by Metra Consulting Group for the Dutch Ministry of Public Health and the Environment. The aim of Metra's study was to identify ways of reducing the environmental nuisance of urban traffic without adding excessively to transport costs.

The main theme of the article is that the traditional idea of an inherent conflict between transport efficiency and the environment is mistaken. Both efficiency and the environment are threatened by the same thing: the excessive and indiscriminate use of vehicles. This comes about because of defects in the fiscal and regulatory framework within which people take transport decisions. Suitable reforms in this framework would simultaneously enhance the environment and improve access for all classes of road user.

In the development of this theme, particular attention is paid to transport activities which tend to be neglected by policy makers, such as walking, cycling and urban goods distribution; and to measures which are not always thought of as instruments of policy at all, such as locational policy and development control, vehicle design, and vehicle taxation, especially of goods vehicles.     

Airport ground transportation management: moving towards the turn of the century

Over the last fifty years ground transportation management (GTM) has slowly evolved into a major function at most larger airports. However, during this time there has been relatively little written discussing the idea, organization structures or duties included within this functional activity. This paper reviews and updates the limited, earlier research. This study replicates initial work done in 1989 and thus provides a short longitudinal view of the airport GTM function. The final results demonstrate the current position of GTM and suggest trends for the future.