Repetitions in individual daily activity–travel–location patterns: a study using the Herfindahl–Hirschman Index

Using Herfindahl–Hirschman Index and the Mobidrive and Thurgau six-week travel diary datasets this paper examines the degree of repetition of individuals’ choices of their daily activity–travel–location combinations. The results show that the repetitiveness of individual activity–travel–mode–location combinations is highly influenced by the individuals’ out-of-home commitments, the intra-household conditions and the availability and the accessibility of the activity locations. Different types of activity have different pattern of repetition. The level of repetition of individual’s daily activity–travel pattern is less correlated to travel mode choice, but more to the individuals’ commitments and obligations. The repetitiveness of mode choices is more related to the conditions or the accessibilities of the activity location, but not directly to the activity itself.     

Highway pricing and capacity choice in a road network under a build–operate–transfer scheme

It is often argued lately that the private sector should be allowed to build and operate roads in a transportation network at its own expense, in return it should receive the revenue from road toll charge within some years, and then these roads will be transferred to the government. This type of build–operate–transfer (B–O–T) projects is currently fashionable worldwide, especially for developing countries short of funds for road construction. One of the important issues concerning a highway B–O–T project is the selection of the capacity and toll charge of the new road and the evaluation of the relevant benefits to the private investor, the road users and the whole society under various market conditions. This paper deals with the selection and evaluation of a highway project under such a B–O–T scheme. For a given road network with elastic demand, mathematical models are proposed to investigate the feasibility of a candidate project and ascertain the optimal capacity and level of toll charge of the new highway. The response of road users to the new B–O–T project is explicitly considered. The characteristic of the problem is illustrated graphically with a numerical example.     

A Gendered Perspective of the Shelter–Transport–Livelihood Link: The Case of Poor Women in Delhi

Abstract

Women form an important part of the workforce originating from the slums in the city of Delhi, India. The paper illustrates that women spend more time travelling on slower modes of transport to access work; the faster modes are more expensive. Their time–poverty demands they look for work at shorter distances from home. The basic argument presented is that their ability to contribute to the alleviation of their standard of living and their status in society is severely curtailed by their limited mobility and the constrained accessibility to the transport system of the city. This transport deprivation becomes further exacerbated by the process of forced eviction and relocation of low‐income households to the periphery of the city, causing the women to lose livelihood opportunities.     

Some comments on origin–destination matrix estimation

Estimation of origin–destination (O–D) matrices from link count data is considered. This problem is challenging because the number of parameters to be estimated is typically larger than the number of network links. As a result, it is (usually) impossible to identify a unique optimal estimate of the O–D matrix from mean link traffic counts. However, information from the covariance matrix of link count data collected over a sequence of days can relieve this problem of indeterminacy. This fact is illustrated through a simple example. The use of second-order statistical properties of the data in O–D matrix estimation is then explored, and a class of estimators proposed. Practical problems of model mis-specification are discussed and some avenues for future research outlined.     

Family changes and public transport use 1984–1987

Panel data are used to investigate what happens when people have some important transitions or changes in their life-cycle, employment status, income, or car ownership. Only three years data are available, and the pace of transition is slow: as a result relevant sample sizes are rather small. The analysis is carried out in two stages: results are given from a two year period, and these are used to generate hypotheses checked with data from the third year.It is found that in many cases the effects on mobility are different from what would be expected from cross-section data. In particular:

Airport–Airline interaction: some food for thought

Abstract

We provide an interpretive analysis of vertical relations between airports and carriers, while assessing the way in which deregulation of the airline market and the privatization of airports have created incentives for airport–airline interaction. In particular, if the vertical structure approach has become the standard approach in air transport research, we add to the literature by discussing three issues that we believe need further understanding. The three issues that we think should be the focus of future research on airport–airline interaction are (i) incomplete contracts and asymmetric information structure; (ii) upstream horizontal complementarities; and (iii) airports as two-sided platforms.     

Modeling household activity–travel interactions as parallel constrained choices

The daily activity-travel patterns of individuals often include interactions with other household members, which we observe in the form of joint activity participation and shared rides. Explicit representation of joint activity patterns is a widespread deficiency in extant travel forecasting models and remains a relatively under-developed area of travel behavior research. In this paper, we identify several spatially defined tour patterns found in weekday household survey data that describe this form of interpersonal decision-making. Using pairs of household decision makers as our subjects, we develop a structural discrete choice model that predicts the separate, parallel choices of full-day tour patterns by both persons, subject to the higher level constraint imposed by their joint selection of one of several spatial interaction patterns, one of which may be no interaction. We apply this model to the household survey data, drawing inferences from the household and person attributes that prove to be significant predictors of pattern choices, such as commitment to work schedules, auto availability, commuting distance and the presence of children in the household. Parameterization of an importance function in the models shows that in making joint activity-travel decisions significantly greater emphasis is placed on the individual utilities of workers relative to non-workers and on the utilities of women in households with very young children. The model and methods are prototypes for tour-based travel forecasting systems that seek to represent the complex interaction between household members in an integrated model structure.     

Car availability change in England and Wales 1971–1981

The aggregate dynamics of car ownership have overshadowed the dynamics of car ownership and availability at the personal and household level. These dynamics have only recently been investigated in more depth. This paper contributes to this work by probing a special data source, theLongitudinal Study (LS) produced by the Office of Population Censuses and Surveys, for the changes in household car availability.The paper describes the LS and explains its special format, as a Census-based ~1% sample of the population of England and Wales.The analysis focuses on the car availability dynamics of a number of groups defined by changes in their life cycle position. Special attention is given to those households where the LS member remains a dependent child throughout the study period.The results show that all studied household types increase and decrease their car holdings, but that there are patterns in this process, which vary from group to group. In particular, the size of the previous car fleet has a different influence on the current fleet size from life cycle group to life cycle group.The paper argues in its conclusion to incorporate these differentials into the further work on car ownership and car ownership change.The work reported here was performed, while the author was a staff member of the Centre for Transport Studies, Imperial College, London.     

Reasonable scheduling for arrival–departure track operations in railway stations

We analyze the train types handled at a section station and the factors affecting the scheduling of the arrival–departure track operation, using the following conditions as our optimization goals: operating the arrival–departure tracks in accordance with a fixed operation scheme, and reducing the influence which the departing–receiving operations impose on shunting operations. We establish a 0–1 integer programming model for formulating a track operation plan. By applying modern sequencing theory, this is transformed into a fixed sequencing model of special parallel machines. We then design a heuristic algorithm to solve the model. Finally, the example of Yiyang railway station is used to verify the advantages of the model and the algorithm. A better operation plan is obtained using MATLAB 7.0 by applying the model and the algorithm provided in the paper, indicating the superiority of our study’s approach.     

Data Review of Transportation Infrastructure Public–Private Partnership: A Meta-Analysis

The limited understanding of public–private partnerships (P3s) for transportation infrastructure finance has been generally attributed to a lack of data. The more fundamental question of how P3 data are utilized in the literature is more relevant and critical, but remains unclear. This study investigates this question by examining the linkages between research objectives and data characteristics through a meta-analysis of infrastructure P3 studies using multinomial regressions. It analyzes 95 empirical studies that adopt actual data, selected from a P3 research database that includes over 345 studies and are classified into five categories including performance, contract, risk, value for money, and institutional factors. Results show that the case studies are less frequently utilized to understand P3s' institutional issues compared to those that focus on P3s' performance or VFM. Survey data are more frequently used to study P3 contracts rather than issues related to P3 project risk. We highlight the need for policy-makers to require continuing disclosure of P3 performance for validating the effectiveness of the procurement model and to improve the practice.     

Transaction Costs in Transport Public–Private Partnerships: Comparing Procurement Procedures

Abstract

In recent years, concern has grown over good practices in the procurement process in public–private partnerships (PPPs). The consensus view is that PPPs are prone to higher transaction costs than traditional public provision. In this paper, we contrast the hypothesis that transaction costs in transport PPPs depend, to a large extent, on the procurement mechanism used in each case, comparing the Negotiated and the Open procedures. Given that PPPs may offer considerable benefits and significant savings over the entire life cycle of the project, it is essential for PPPs to minimize those costs that undermine efficiency gains and that deter private involvement. The quantitative analysis undertaken in this paper highlights that there is room for important savings in the tendering of PPP transport infrastructure projects, using an Open procedure.     

Applying a structured simulation-based methodology to assess carpooling time–space potential

Abstract

Increasing urban traffic congestion calls for the study of alternative measures. One such measure is carpooling, a system in which a person shares his private vehicle with one or more people in a commuter trip. In principle, this system could lead to potentially significant reductions in the use of private vehicles; however, in practice it has achieved limited success. In this paper, we apply a simulation-based methodology that uses aggregated data from commuter trips in an urban area to create compatible and feasible random trips. These are then analyzed through a heuristic process recursively to find grouping possibilities, thus producing indicators of carpooling potential such as the percentage of matched trips. Using this methodology, simulations are run for the Lisbon Metropolitan Area (Portugal) and results show that an increase in the number of participants in a carpooling scheme will only increase the probability of matching up to a certain point, and that this probability varies significantly with time–space trip attributes.     

Recognition and tracking of spatial–temporal congested traffic patterns on freeways

The two models FOTO (Forecasting of Traffic Objects) and ASDA (Automatische Staudynamikanalyse: Automatic Tracking of Moving Traffic Jams) for the automatic recognition and tracking of congested spatial–temporal traffic flow patterns on freeways are presented. The models are based on a spatial–temporal traffic phase classification made in the three-phase traffic theory by Kerner. In this traffic theory, in congested traffic two different phases are distinguished: “wide moving jam” and “synchronized flow”. The model FOTO is devoted to the identification of traffic phases and to the tracking of synchronized flow. The model ASDA is devoted to the tracking of the propagation of moving jams. The general approach and the different extensions of the models FOTO and ASDA are explained in detail. It is stressed that the models FOTO and ASDA perform without any validation of model parameters in different environmental and traffic conditions. Results of the online application of the models FOTO and ASDA at the TCC (Traffic Control Center) of Hessen near Frankfurt (Germany) are presented and evaluated.     

A new fuzzy approach to estimate the O–D matrix from link volumes

Abstract

Estimation of the origin–destination (O–D) trip demand matrix plays a key role in travel analysis and transportation planning and operations. Many researchers have developed different O–D matrix estimation methods using traffic counts, which allow simple data collection as opposed to the costly traditional direct estimation methods based on home and roadside interviews.

In this paper, we present a new fuzzy model to estimate the O–D matrix from traffic counts. Since link data only represent a snapshot situation, resulting in inconsistency of data and poor quality of the estimated O–Ds, the proposed method considers the link data as a fuzzy number that varies within a certain bandwidth. Shafahi and Ramezani's fuzzy assignment method is improved upon and used to assign the estimated O–D matrix, which causes the assigned volumes to be fuzzy numbers similar to what is proposed for observed link counts. The shortest path algorithm of the proposed method is similar to the Floyd–Warshall algorithm, and we call it the Fuzzy Floyd–Warshall Algorithm. A new fuzzy comparing index is proposed by improving the fuzzy comparison method developed by Dubois and Prade to estimate and compare the distance between the assigned and observed link volumes. The O–D estimation model is formulated as a convex minimization problem based on the proposed fuzzy index to minimize the fuzzy distance between the observed and assigned link volumes. A gradient-based method is used to solve the problem. To ensure the original O–D matrix does not change more than necessary during the iterations, a fuzzy rule-based approach is proposed to control the matrix changes.     

Hedonic versus homogeneous output specifications of railroad technology: Belgian railroads 1950–1986

The purpose of this paper is twofold. First, using data on Belgian railroad operations, we provide the first application of hedonic output aggregation to the railroad industry. Second, we compare the traditional homogeneous output approach with the use of these hedonic aggregates and carefully evaluate differences in estimates of input substitution possibilities, returns to scale, and productivity growth. It is found that ignoring the role of operating characteristics in cost analyses implies substantial bias in estimates of railroad technology.     

Rail Infrastructure: Challenges for Cost–Benefit Analysis and Other ex ante Evaluations

Abstract

Cost–benefit analysis (CBA) plays a major role in the ex ante evaluation of rail projects in many western countries. At first sight carrying out a CBA for rail projects seems straightforward, since cost estimates are almost always available, and the most dominant benefits are generally known, being the travel time saved and the increase in consumer surplus due to induced demand. However, the practice is much more complex: the quality of current estimates for costs and benefits is often poor and several benefits-related aspects are ignored. This article gives an overview of the challenges in improving the quality of CBAs for rail projects.     

Applications of Random-Utility-based Multi-region Input–Output Models of Transport and the Spatial Economy

Abstract

An introduction to random-utility-based multiregional input–output models used for the purpose of spatial economic and transport interaction modelling is provided. The main methodological developments and important results of a dozen applications from the years 1996–2013 are described. This is followed by an outlook of potential future directions. Further research is mainly needed in five areas: (a) overall validation of the method, perhaps through back-casting applications on infrastructure plans with observed trade impacts; (b) extensions of trade coefficient models to add realism and improve accuracy; (c) the use of multi-scale modelling to capture interdependencies between geographical scales and to improve the representation of exports and imports; (d) improvements in the representation of price effects, as well as innovation and technological progress, by way of variable technical coefficients; and (e) a deeper investigation of the algorithm used to include elastic selling prices.     

Simultaneous estimation of an origin–destination matrix and link choice proportions using traffic counts

A procedure for the simultaneous estimation of an origin–destination (OD) matrix and link choice proportions from OD survey data and traffic counts for congested network is proposed in this paper. Recognizing that link choice proportions in a network change with traffic conditions, and that the dispersion parameter of the route choice model should be updated for a current data set, this procedure performs statistical estimation and traffic assignment alternately until convergence in order to obtain the best estimators for both the OD matrix and link choice proportions, which are consistent with the survey data and traffic counts.Results from a numerical study using a hypothetical network have shown that a model allowing θ to be estimated simultaneously with an OD matrix from the observed data performs better than the model with a fixed predetermined θ. The application of the proposed model to the Tuen Mun Corridor network in Hong Kong is also presented in this paper. A reasonable estimate of the dispersion parameter θ for this network is obtained.     

Origin–destination missing data estimation for freight transportation planning: a gravity model-based regression approach

This paper develops a log-linear regression approach to estimate missing data in a sparse origin–destination (O–D) matrix assuming the sampled or observed O–D trips follow a good gravity pattern. The approach is tested with randomly selected samples from the known portions of 1997, 2002, and 2007 US Commodity Flow Survey (CFS) O–D value and tonnage matrices and validated with 2007 US O–D tonnage matrix at the state level. The missing data are also estimated for the 2007 CFS tonnage matrix with the best intercept and coefficients obtained using all known entries of the matrix. The concept of the approach can be extended beyond the gravity model to any strong mathematical pattern embedded in the known set of a sparse O–D matrix to estimate its missing cells.     

Transportation–land-use interaction: empirical findings in North America,and their implications for modeling

The last two decades have witnessed the implementation of various policies based on land-use to address problems stemming from automobile ownership and use. There are, however, questions with respect to the efficacy of such policies. This paper therefore reviews the literature on empirical studies of the transportation–land-use interaction with the objective of identifying the current state of knowledge concerning the interactions, particularly with respect to the impact land-use policies are likely to have on the system. The focus is on studies conducted in North America. The results are mixed; some studies conclude that urban densities, traditional neighborhood design schemes, and land-use mix have an impact on auto ownership and use. Other studies find the impact of such variables to be at best marginal. Gaps in our understanding of the interaction are identified. These are found to be primarily the result of data limitations and methodological weaknesses. A detailed discussion of the implications of the findings for the development and application of integrated transportation–land-use models is provided, with the recommendation that without such an integrated approach to analyzing the transportation–land-use interaction, any study of impacts of urban form on travel behavior is likely to yield erroneous results.