Does the choice model method and/or the data matter?

The opportunity to have seven data sets associated with a stated choice experiment that are very similar in content and design is rare, and provides an opportunity to look in detail at the empirical evidence within and between each data set in the context of a range of discrete choice estimation methods, from multinomial logit to latent class to scale multinomial logit to mixed logit, and the most general model, generalized mixed multinomial logit that accounts for preference and scale heterogeneity. Given the problems associated with data from different countries and time periods, we estimate separate models for each data set, obtaining values of travel time savings that are then updated post estimation to a common dollar for comparative purposes. We also pooled all data sets for a scaled MNL model, treating each data set as a set of three separate utility expressions, but linked to the other data sets through scale heterogeneity. This is not behaviourally appropriate with MNL, latent class or mixed logit. The main question investigated is whether there exists greater synergy in the willingness to pay evidence within model form across data sets compared to across model forms within data sets. The evidence suggests that there is a relatively greater convergence of evidence across the choice models, with the exception of generalized mixed logit, after controlling for data set differences; and there is strong evidence to suggest that differences between data sets do matter.     

Workshop report - A successful contractual setting

Successful public transport service contracts can be judged against procedural and outcome criteria, located within an integrated strategic, tactical and operational level framework for planning and delivery. Clear goal setting at the strategic level sets the basis for supportive tactical system planning and for service delivery that meets goals. The workshop considers relevant success criteria and key matters that need to be resolved for their achievement. Market growth potential and the governmental attitude to supporting service growth are important issues shaping the contractual environment. The growing interest in negotiated performance-based contracts and the role of trust between the operator and the authority are also matters for particular attention.     

手机APP出行调查系统开发及其模型应用研究

出行调查是出行需求预测模型的重要的数据来源,而国内外近几年使用的调查方法费时费力、数据量不大且很多处于理论阶段无法应用到实际中.为了解决当前调查方法中存在的问题,设计了一套基于手机APP的出行调查系统,同时还探讨了将收集到的出行数据运用到交通规划模型中的问题.该系统在注册填写个人信息以及收集轨迹数据的基础上,利用当前定位技术无法准确获知居民室内位置的特点,以达到收集居民出行数据的目的.具体方法是计算一定时间内轨迹数据的定位精度和速度来判断该段时间居民是否停留,然后将识别出的停留点根据距离进行合并,居民出行结束后在合并后的停留点位置填写相应的出行信息.从在上海青浦区的居民调查中可知,此系统使用的停留点识别方法其识别精度达到96%,因此利用该方法能够客观地收集居民出行过程中活动的空间位置和时间信息,对提升出行预测模型的精度具有重要意义.     

Applying Public Participation Geographic Information Systems for Coastal Wading Bird Conservation

Coastal estuaries in the northern Gulf of Mexico are important habitat for wading birds, but are threatened by land use and ecological changes. Conservation has been demonstrated to be more effective when stakeholders are included in the decision-making process. Public Participation Geographic Information Systems (PPGIS) facilitates the inclusion of stakeholder preferences in the planning process by allowing a direct spatial comparison with other ecological data. In this study, we used a PPGIS survey of residents of two counties on Alabama’s Gulf Coast to identify wading bird conservation hotspots as identified by local residents. Additionally, we assessed the ability of general public respondents to accurately identify wading bird habitat, determined whether participants associated wading bird habitat with particular land cover types, and examined whether respondents identified areas with high wading bird species richness. We found that respondents could accurately identify suitable wading bird habitat on a map of the study area, but underrepresented riparian forest, which is an important habitat for many wading bird species. Additionally, participants tended to prioritize areas that support higher wading bird species richness. Thus, this study demonstrated how PPGIS can function as an important tool for incorporating both stakeholder management preferences and identifying knowledge gaps.     

Assessing the social costs of urban transport infrastructure options in low and middle income countries

ABSTRACT

This paper develops cost models for urban transport infrastructure options in situations where motorcycles and various forms of taxis are important modes of transport. The total social costs (TSCs) of conventional bus, Bus Rapid Transit (BRT), Monorail, Metro (Elevated Rail), car, motorcycle, Taxi and Uber are calculated for an urban corridor covering operator, user and external costs. Based on the parameters for a 7?km corridor in Hanoi, Vietnam, the results show the lowest average social cost (ASC) transport modes for different ranges of demand. Motorcycle might be the best option at low demand levels while conventional bus has advantages with low-medium demand. At medium demand levels, bus-based technologies and Monorail are competitive options while Metro, with a higher person capacity, is the best alternative at the highest demand levels. Compared to other modes, the ASCs of car and Taxi/Uber are greater because of high capital cost (related to vehicles) per passenger and low occupancy. Transport planners and decision makers in low and middle income countries (LMICs) can draw on the findings of this study. However, various limitations are identified and additional research is suggested.     

The growing gap in pedestrian and cyclist fatality rates between the United States and the United Kingdom,Germany, Denmark,and the Netherlands, 1990–2018

ABSTRACT

Using official national data for each country, this article calculates trends in walking and cycling fatalities per capita and per km in the USA, the UK, Germany, the Netherlands, and Denmark. From 1990 to 2018, pedestrian fatalities per capita fell by 23% in the USA vs. 66%–80% in the other countries; cyclist fatalities per capita fell by 22% in the USA vs. 55%–68% in the other countries. In 2018, pedestrian fatality rates per km in the USA were 5–10 times higher than in the other four countries; cyclist fatality rates per km in the USA were 4–7 times higher. The gap in walking and cycling fatality rates between the USA and the other countries increased over the entire 28-year period, but especially from 2010 to 2018. Over that 8-year period, per-capita fatality rates in the USA rose by 19% for pedestrians and 11% for cyclists; per-km fatality rates rose by 17% for pedestrians and 33% for cyclists. By comparison, fatality rates either fell or remained stable in the four European countries. We reviewed the relevant literature to identify factors that might help explain the much lower walking and cycling fatality rates in Europe compared to the USA. Possible explanatory factors include better walking and cycling infrastructure; lower urban speed limits; fewer vehicle km travelled; smaller and less powerful personal motor vehicles; and better traffic training, testing, and enforcement of traffic regulations. We recommend that the USA consider implementing an integrated package of mutually reinforcing safety measures such as those that have been successfully implemented in the Netherlands, Denmark, and Germany to reduce pedestrian and cyclist fatality rates.     

An evaluation of the user characteristics of an open access DRT service

The successful provision of Demand Responsive Transport (DRT) in Europe, Australia, UK and the US has been addressed in several substantial studies and projects. The general finding of these studies is that DRT is a suitable transport solution in particular areas and can deliver social inclusion and community building objectives. Existing research confirms that DRT is particularly useful for connecting isolated communities and population groups to essential services such as healthcare and is cost-effective in terms of contributing greatly to community wellbeing. However, many existing DRT services are still not performing to their true potential, and many of them could not be viable as commercial services. The aim of this study is to develop greater understanding of DRT services from the passengers’ perspective using a case study of LinkUp in Tyne and Wear, one of the most successful DRT schemes in the UK. The paper has two key objectives: (a) to critically review, in the context of the detailed case study the general characteristics of the selected DRT scheme; and (b) to analyse and interpret the findings from a detailed survey of users (who are predominately elderly and female) with regard to passenger characteristics, their attitudes and perception of the service and their suggestions for improvement.     

Acceptability of Beijing congestion charging from a business perspective

Transportation - Beijing is China’s national capital, a major economic center, and home to nearly 22 million people. The city currently suffers from serious traffic congestion and extreme air...     

New appraisal values of travel time saving and reliability in Great Britain

Transportation - This paper provides an overview of the study ‘Provision of market research for value of time savings and reliability’ undertaken by the Arup/ITS Leeds/Accent consortium...     

Wave analysis of porous geometry with linear resistance law

The wave diffraction-radiation problem of a porous geometry of arbitrary shape located in the free surface of a fluid is formulated by a set of integral equations, assuming a linear resistance law at the geometry. The linear forces, the energy relation and the mean horizontal drift force are evaluated for non-porous and porous geometries. A geometry of large porosity has an almost vanishing added mass. The exciting forces are a factor of 5–20 smaller compared to a solid geometry. In the long wave regime, the porous geometry significantly enhances both the damping and the mean drift force, where the latter grows linearly with the wavenumber. The calculated mean drift force on a porous hemisphere and a vertical truncated cylinder, relevant to the construction of fish cages, is compared to available published results.