Showing papers in "The International Journal of Urban Sciences in 2014"

Activity-based models of travel demand : promises, progress and prospects

Abstract: Because two decades have almost passed since the introduction of activity-based models of travel demand, this seems the right time to evaluate progress made in the development and application of these models. This invited paper seeks to discuss the initial promises of activity-based models as an alternative to four-step and tour-based models, summarize progress made and identify still unsolved issues that require further research.

Ontology-based multi-agent system for urban freight transportation

Abstract: Congestion, pollution, and safety are some of the most worrisome side-effects of the urban goods movement activities. These problems are generally attributed to the underlying characteristics of the domain such as heterogeneous stakeholders, their conflicting objectives and resulting distributed decision-making. Such autonomous decision-making stakeholders do not efficiently cooperate and coordinate while performing city logistics activities. The ensuing inefficient use of resources (e.g. goods delivery vehicle, time, etc.) gives rise to the above-mentioned problems. To reduce the negative externalities of urban goods movement, we first must understand the decision-making process of the city logistics stakeholder under different situations. Agent-based simulation modelling technique is such an approach where distributed decision-making of the multiple stakeholders can be included by modelling each entity as an autonomous agent. In this paper, we propose the use of a knowledge data model of urban freight domain - city logistics ontology - to develop an agent-based model. City logistics ontology is a knowledge model which includes city logistics entities (e.g. stakeholders, resources, etc.) and relationships between them in a structured form. The paper focuses on the usefulness of ontology in the development of agent-based model for city logistics domain, and attempts to demonstrate the effectiveness of agent technology in analysing the urban freight decision-making processes. © 2014 © 2014 The Institute of Urban Sciences.

Collaboration in urban logistics: motivations and barriers

Abstract: Urban logistics activities, while essential to the development of cities, also contribute to congestion and pollution if poorly managed. Synchronizing the last mile of delivery is critical, but challenging to implement. Collaboration between the stakeholders is thus needed and timely to improve the efficiency of last mile delivery in a growing city while advancing environmental sustainability. This paper is an exploratory study undertaken in Singapore, to identify the motivations and barriers to collaboration in urban logistics, which may influence a stakeholder's decision to participate. Our initial results suggest that the expected benefits (motivation) and the competitive intelligence risks (barrier) influence the participation decision.

A location-based accessibility analysis to estimate the suitability of urban consolidation facilities

Abstract: This paper proposes a location-based accessibility analysis framework to assess the suitability of urban consolidation platform location scenarios. First, an overview of urban consolidation is presented to identify the main types of platforms and the related scientific work. Then, the proposed framework is presented on the form of a three-step procedure. The first step is to generate goods transport demand using a delivery-to-commodity model. The second consists in estimating routes both for serving the consolidation platforms supplied by shippers and for delivering customers afterwards, using a VRP algorithm. The third step consists in performing an accessibility calculation. Starting from the distances travelled obtained by the vehicle routing algorithm, travel times (including vehicle running and stopping times) are estimated, after which a location-based accessibility indicator based on transport cost is obtained. To illustrate the framework proposed, an example of application for the city of Lyon (Fr...

An analysis of the connection between built environment, physical activity and health: comparing three urban neighbourhoods from Shiraz, Iran

Abstract: There is currently considerable interest in discovering the effects of physical form and built environment on the physical activities done by people. The increasing concerns of obesity, especially among children, women, and old people, increase the necessity of research in this area. However, most studies in this area are from western developed countries and their results cannot be transferred to developing countries where the economic and social context is different. This study attempted to investigate the link between built environment, socio-economics, and physical activity among adults by comparing three neighbourhoods from Shiraz, Iran, using multiple criteria, including analysis of variance (ANOVAs), t-tests, and the correlation coefficient. The hypothesis was that these variables were positively related to physical activity for either transportation or sporting/exercise/leisure activities. An integrated database of built environment characteristics and activity-related features was developed for a ...

Spatial change in urban employment distribution in Seoul metropolitan city: clustering, dispersion and general dispersion

Abstract: The primary purpose of this paper is to identify whether the spatial distribution of employment moves towards clustering or dispersing by examining the change in spatial distribution of employment in Seoul metropolitan city. This paper first identifies the centre and subcentres with the cut-off approach and then examines the changing direction of employment distribution by estimating both monocentric and polycentric employment density functions. For the estimation, this paper utilizes a three-digit industrial classification data for the years 2000, 2005 and 2010, which contain detailed information on distribution of employment. The main findings are as follows. First, the spatial structure of Seoul is apparently polycentric. Second, the central business districts (CBD) loses its dominance over Seoul's economy in terms of the number of employment, and the newly emerging Gangnam subcentre became the largest employment centre in Seoul. Third, the estimates of employment density functions (both monocentric an...

City logistics long-term planning: simulation of shopping mobility and goods restocking and related support systems

Abstract: The growing necessity to improve city sustainability and liveability has pushed local administrators to look also at medium/long-term city logistics measures, such as land-use governance policies. In order to assess long-term scenarios, it is necessary to have models and methods able to take into account the effects on shopping mobility and goods restocking, generated by these classes of measures (e.g. relocation of shopping zones). Besides, we have to consider that modifications of shopping attitudes, deriving from changes of demographic and socio-economic characteristics of end consumers, can impact on purchasing behaviour and hence on restocking mobility. This paper discusses a number of issues related to the simulation of medium/long-term scenarios and presents a system of models that consider shopping mobility and restocking jointly. The presented shopping demand models, in combination with urban restocking models, are implemented within a simulation support system named City Logistics Analysis and S...

City logistics through the canals? A simulation study on freight waterborne transport in the inner-city of Amsterdam

Abstract: This study investigates whether distributing goods across the water to the city of Amsterdam can be a potential future solution considering the busy traffic of the pleasure crafts and touring boats on the canals. A simulation model was developed to analyse the logistics performances and traffic influences for different fleet size configurations. The simulation tests have shown that four vessels are needed to guarantee the requested delivery times, a sufficient loading rate (82%) was generated for each ship, and no significant delays will happen due to interaction with other water traffic. Conclusion of this study is that a waterborne city logistics concept through the canals of Amsterdam has demonstrated the capability to reduce congestion in the inner-city and is able to satisfy the delivery requirements of the shopkeepers without significant interference with other waterborne traffic.

Model of debris collection operation after disasters and its application in urban area

Abstract: Management of debris is a concern after any major disaster. In particular, debris removal after a disaster presents challenges unique to that disaster. Often, the debris removal process takes months or even years to finish. It is likely to be a concern for some time to come since there exists many factors that make it such a costly and complex operation. The cost is mostly arising from the cost of collection and transportation to the disposal sites. The debris collection and transportation routing problem is the subject of this study. The debris collection operation after disasters is a new capacitated arc routing problem (CARP). The uniqueness of this problem is due to the limited access from one section to the other, as a result of the blocked access by debris. Therefore a new constraint, which is developed in this study as access possibility constraint, has been added to the classical CARP. A tabu search meta-heuristics is also proposed to solve the augmented CARP formulation for the debris collection ...

Urban containment policies and urban growth

Abstract: While there has been controversy over the negative and positive effects of urban containment policies (UCPs), little is known about their impact on urban growth with policy tightness. This paper empirically analyses UCP impacts on changes in population, employment, built-up areas, and housing values. A simultaneous equation model is estimated, with, as endogenous variables, the above changes at the city level. Both stringent containment policies (SCP), such as greenbelts and urban growth boundaries, and less stringent containment policies (LSCP), such as urban service areas, are found to have significant impacts on changes in population, employment, housing values, and city land area. SCPs have positive effects on changes in population and housing values twice as large as LSCPs, suggesting that SCPs more successfully accommodate new growth within growth boundaries and that housing values increase with the tightness of UCPs.

London 2012: changing delivery patterns in response to the impact of the Games on traffic flows

Abstract: The paper addresses road freight transport operations during the London Olympic and Paralympic Games in 2012. It presents work carried out prior to the Games to understand pre-Games patterns of freight deliveries in London (for both light and heavy goods vehicles) and the results of modelling work carried out to assess the likely impacts of the Games road restrictions on freight operations. The modelling results indicated that increases in total hours travelled carrying out collection and delivery work would range from 1.4% to 11.4% in the six sectors considered. The results suggested increases in hours travelled in excess of 3.5% in four of the six sectors modelled. The possible actions that could be taken by organizations to reduce these negative impacts were also modelled and the results indicated that such actions would help to mitigate the impact of the road restrictions imposed on operators during the Games. The actual impacts of the 2012 Games on transport both in general terms and specifically in terms of freight transport are also discussed, together with the success of the actions taken by Transport for London (TfL) to help the road freight industry. The potential freight transport legacy of the London 2012 Games in terms of achieving more sustainable urban freight transport is considered and the steps being taken by TfL to help ensure that such a legacy can be realized are discussed. Such steps include policy-makers continuing to collaborate closely with the freight industry through the ‘London Freight Forum’, and TfL's efforts to encourage and support companies revising their delivery and collection times to the off-peak; improving freight planning in the design and management of TfL-funded road schemes; electronic provision of traffic information by TfL to the freight industry, and the further development of freight journey planning tools.

Multi-agent systems modelling approach to evaluate urban motorways for city logistics

Abstract: Government road authorities are constantly faced with the challenges of urbanization and traffic congestion requiring them to make good decisions for infrastructure developments. Several developed and developing countries have focused their concerns on building motorways for private and public transports for intercity connectivity and economic growth in the past. However, very few evaluation models were concerned about urban motorways for the benefit of urban freight transport. There may not even be an evaluation model for urban motorways development, which has considered the routing behaviour of truck movements in urban areas, especially if the main purpose for the urban motorway is for improving city logistics. Faced with the problems and concerns of the road authorities in Japan regarding capacity increase measures or other freight management schemes, this paper is an initial step to explore and provide the methodology to support the road authorities in their decision for urban motorway alternatives.

Relationships between neighbourhood environments and residents’ bicycle mode choice: a case study of Seoul

Abstract: The purpose of this study is to analyse the characteristics of neighbourhood environments affecting residents’ bicycle mode choice through a case study of Seoul. In this study, neighbourhood environments and other socio-demographic factors were used as explanatory variables in a causal model. The main data source used for this research was the 2006 Household Travel Survey, from which 214,978 observations were selected as the final sample. Statistical analysis was carried out by applying the random intercept logit model. The results of analysing the factors that affect the residents’ bicycle mode choice can be summarized as follows: first, the gender, income, occupation, vehicle ownership status, and residential type have statistically significant correlations with the bicycle mode choice. In addition, the travel time and travel distance affect the bicycle mode choice. Second, a high level of land use mix results in more bicycle travel. However, unlike what is shown in previous western studies, residential...

Application of exact route optimization for the evaluation of a city logistics truck ban scheme

Abstract: This paper presents an application of the exact solution approach for the Vehicle Routing Problem with Soft Time Windows based on the column generation scheme developed earlier by the authors, for evaluating a truck ban scheme from the environmental improvement aspect on a realistic logistics instance based on the Vehicle Information and Communication System data, which is an Intelligent Transportation Systems (ITS) application in Japan. Two different types of truck ban schemes are evaluated, one which denies truck entry on congested links (with average speeds lower than a threshold) and the other with and without the availability of the ITS-based data to freight firms. It was found that the Uniform truck ban on low travel speed links can result in a win-win situation, improving the environmental conditions as well as reducing the operation cost for freight carriers in a scenario where freight carriers do not have access to ITS-based travel time information. While the use of an exact optimization method a...

A study on the impact of soft location factors in the relocation of service and manufacturing firms

Abstract: This paper empirically studied relocation factors for manufacturing and service firms in the Seoul Metropolitan Area. The purpose of this study is to identify the influence not only of traditional firm location factors, but also of quality of life factors. A firm's location decision is an assertive action (behaviour) to maximize profit that may have a large ripple effect on the regional economy and society. This study used a binary logit model to analyse location choice factors during firm relocations. As of December 2011, the number of firms registered with the Korea Chamber of Commerce and Industry was 117,157. Of these firms, 36,598 were selected. The firms’ locations could be tracked because their names and owners did not change from December 2006 to December 2012. Of the selected firms, 8328 (22.8%) relocated during this period. It can be considered that 4.6% of all firms relocate in a year. A geographic information system database was built using location addresses of the 8328 firms. This study exhi...

An estimation of freight flow using secondary data: a case study in Belo Horizonte (Brazil)

Abstract: This paper presents a methodology to estimate freight flows using secondary data. Problems associated with urban freight are of increasing concern to both public and private institutions. Low efficiency due to traffic congestion, lack of policies and restricted information for decision-making are common in the Brazilian context. Thus, this paper aims at describing a simple, but effective methodological approach for data processing in order to support decision-making in the context of urban freight in Brazil. The proposal consists of gathering common available data in the country as well as Minas Gerais State and applying the method in a study area defined according to a set of different parameters. The results achieved for the Belo Horizonte central region indicate the effectiveness of the methodology as well as the need for a systematic data collection in order to improve future results.

Benefits of rerouting railways to tunnels in urban areas: a case study of the Yongsan line in Seoul

Abstract: As ground transport infrastructure causes diverse externalities such as noise and urban separation, the rerouting of such facilities to tunnels is one practical option to resolve the problem of social costs. Although such a mega-project is normally associated with huge budgets, this solution can also generate useful benefits for society. This paper explores these benefits using the Yongsan line in Seoul, Korea, as a case study. Four representative values are considered. Noise reduction benefits are represented by two cost components: annoyance and health risk. Railway crossings are evaluated by operating and accident costs. Excess travel time for pedestrians is used as the key index to measure urban separation. Finally, the value of the landscape is quantified based on an anthropocentric method in the form of the transfer of benefits. In the calculation of these benefits, the local parameters of Korea are applied for realistic estimates while a universal methodology for each component is adopted for secur...

Comparing the environment for elderly pedestrians among different-sized cities of Gyeonggi province in Korea

Abstract: The purposes of this study are to identify assessment indices for evaluating the environment for elderly pedestrians and to compare the pedestrian environment surrounding senior welfare centres among large, mid-size, and small cities. To that end, a set of assessment indices and weighted values were decided and field assessments were carried out in seven cities in Gyeonggi province. Research methods such as reviews of pedestrian assessment tools, field assessment, and an analytic hierarchy process survey were conducted. The comparative analysis of the assessment results suggests the following policy implications. First, Aesthetics including attractive views, tree shade, and building facades was found to be important, let alone Safety, which represents the presence of path and traffic control devices. Second, there is a considerable discrepancy in the pedestrian environment surrounding senior welfare centres between large cities and mid-to-small cities, which pose a serious impediment to both balanced urba...

Analysing the cost efficiency of parcel distribution networks with changes in demand

Abstract: Demand for parcel delivery services has rapidly increased recently mainly due to the tremendous growth of e-commerce worldwide. Responding to changes in parcel volume with small-sized frequent shipments poses a great challenge to parcel delivery companies, as they need to rationalize the cost of operating and maintaining their physical distribution networks, while achieving acceptable level of on-time delivery rate throughout their large market areas. The objective of this paper is to analyse the impact of increasing demand on the parcel distribution network structures in terms of minimizing transportation and sortation costs. Based on the case of South Korean parcel delivery industry, this study simulated various types of networks including point-to-point, hub-and-spoke, and multiple hub structure with parcel demand changes. This study can provide well-prepared adaptive network design strategies to parcel delivery service providers for various possible demand changes over the long term.

Delimiting boundaries of market areas of central places using the density of retail facilities in an urban space

Abstract: When Christaller's central place theory is applied to an anisotropic urban space, the hierarchical structure of the central places in hexagon shapes does not appear. Thus, we have difficulties delimiting boundaries of market areas of central places. In order to overcome this limitation, we suggest the geographic information system (GIS) method based on a hydrological modelling which uses raster density and apply the method to the retail facilities of Seoul, Korea. Kernel density function is used to measure the density of retail facilities, and search radii are set up as 500, 1000, and 5000 m by considering the size of the neighbourhood unit, the neighbourhood district, and the sub-centre region. As a result, we confirm market areas of central places with irregular shapes, which become nested in those of higher order central places. This means that central places in an urban space have the hierarchy, which is the core concept of Christaller's theory. In order to evaluate the result of delimiting market are...

Analysis on crash reduction factors for road segment safety

Abstract: The CRF (crash reduction factor), which has credibility that can quantitatively explain effects on traffic accidents in the field of traffic safety, is an important area which can evaluate the safety of roads. In this research, the influence on traffic safety using accident data was investigated, focusing on road factors and surrounding environmental factors from road engineers’ point of view. In this study, the predictive levels of CRFs, which were used to evaluate the safety of roads by quantitatively expressing effects on traffic accidents, were developed. Accident models were developed by using data from roadways. It was shown that rather than Poisson or negative binomial, zero-inflated Poisson was more appropriate when the frequency in which 0 (zero) case occurs is high. It is also shown that the horizontal curve and radius, whether a concave section exists, the number of lighting systems, whether level terrain or mountainous terrain exists, and the number of crosswalks have influence on accident in ...

The structure of the green certification scheme for the neighbourhood and application to the new town development: the case of Magok, Seoul, Korea

Abstract: The green certification scheme for neighbourhoods is believed to be a meaningful means to realistically and effectively achieve a low-carbon city. Many advanced countries have already developed their own green certification schemes and typical examples are LEED (Leadership in Energy and Environmental Development), BREEAM (Building the Research Establishment Environmental Assessment Method), and CASBEE (Comprehensive Assessment System for Building Environmental Efficiency). However, there are few studies on green certification for neighbourhoods in Korea. This paper presents the structure of the green certification scheme that is applicable to the Korean neighbourhood unit. The green certification scheme is developed through the following four steps: the first step identifies the mechanism of the carbon generation within the neighbourhood based on the IPCC guidelines. Next, five sectors are determined from the carbon emission mechanism identified, and evaluation standards are systematically derived from ea...

An empirical analysis on the housing prices in the Pearl River Delta Economic Region of China

Abstract: As the region with the fastest and highest level of economic growth in China, the instability of the Pearl River Delta Economic Region's (PRDER) housing prices has always been a social focus. In order to make housing price stabilization policies effective, more research is required about China's housing market mechanism and the influential factors of housing prices. China used to be a socialist economy since 1949. Deng Xiaoping began China's economic reform and introduced market principles in 1978. Since then China's housing had undergone transition from socialist system to market economy. After 1998, China had housing market economy. This paper aims to understand the housing price behaviour of newly transformed housing market economy of China by analysing the influential factors of China's housing prices compared to that of conventional market economy. This study established a fixed-effect model of panel data and conducts empirical analysis on the influential factors of housing prices in nine cities in t...

Development of a Korea highway safety evaluation proto type model on the concept of IHSDM crash prediction module

Abstract: This study tries to develop a Korea highway safety evaluation proto type model for quantified safety evaluation. We develop a base model and crash modification factors (CMFs) through reviewing the procedures and methodologies in Highway Safety Manual. At the same time, we try to carefully consider collectable data and roadway environment of Korea that are different from the USA. CMFs are developed through models and expert's judgement. Developed CMFs are for driveway density, pedestrian crosswalk, existence of median, terrain types, and land-use types. Also, verification of the developed base model and CMFs were performed using two routes of Korea's rural two-lane highways while comparing with roadway safety design synthesis and Crash Prediction Module (CPM) of Interactive Highway Safety Design Model (IHSDM). Applicability analysis was then performed in two aspects of predictability and adaptability of the proto type model. As a result, CMFs and predicted accident estimates of CPM are similar with the dev...

A comparative assessment of edge-effect with syntax integration generated in axial and unit-segment approaches to modelling vehicular movement networks

Abstract: Unit-segment analysis – a recent development in space syntax – has shown better results in modelling vehicular movement networks than the traditional axial analysis merely by using configurational measures, integration results, of roadway segments of urban grids. Despite this advancement, some of the findings of the unit-segment model have remained controversial especially in the academic community. The concern of edge-effect is one of them. That is, at the practical level, how is it possible for a unit segment analysis to predict vehicular movement of a specified urban roadway grid with high accuracy when the analysis model does not consider trips that enter into the grid from outside? This paper throws a deeper insight into this question by evaluating the intensities of edge-effect generated by both the syntax models. By using the case of Tech Terrace, a residential neighbourhood of the city of Lubbock in West Texas, and then the city itself, the study produces extensive theoretical as well as empirical...