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  • Conference paper
    Sidiropoulos S, Majumdar A, Ochieng W, Schuster Wet al., 2014,

    Levels of organisation in Multi-Airport System

    , Transportation Research Board 94th Annual Meeting
  • Journal article
    McCoy EJ, Graham DJ, Stephens DA, 2014,

    Quantifying causal effects of road network capacity expansions on traffic volume and density via a mixed model propensity score estimator

    , Journal of the American Statistical Association, Vol: 109, ISSN: 1537-274X

    Road network capacity expansions are frequently proposed as solutions to ur-ban traffic congestion but are controversial because it is thought that theycan directly ‘induce’ growth in traffic volumes. This paper quantifies causaleffects of road network capacity expansions on aggregate urban traffic volumeand density in US cities using a mixed model propensity score (PS) estimator.The motivation for this approach is that we seek to estimate a dose-responserelationship between capacity and volume but suspect confounding from bothobserved and unobserved characteristics. Analytical results and simulationsshow that a longitudinal mixed model PS approach can be used to adjust ef-fectively for time-invariant unobserved confounding via random effects. Ourempirical results indicate that network capacity expansions can cause substan-tial increases in aggregate urban traffic volumes such that even major capacityincreases can actually lead to little or no reduction in network traffic densi-ties. This result has important implications for optimal urban transportationstrategies.

  • Journal article
    Li H, Graham DJ, Majumdar A, 2014,

    Effects of changes in road network characteristics on road casualties: An application of full Bayes models using panel data

    , Safety Science, Vol: 72, Pages: 283-292, ISSN: 0925-7535

    In order to ensure a high level of road safety, road network planning needs to be based on the best knowledge available of the effects of road design on road safety. In this study, we look into how changes in road network characteristics affect road casualties. An approach based on traffic assignment is proposed in order to estimate the traffic exposure at ward level. We apply a widely used approach for before–after evaluation studies, the Bayesian method. We also use a panel semi-parametric model to estimate the dose–response function for continuous treatment variables. The result suggests that there are more casualties in areas with better connectivity and accessibility, where more attention should be paid to safety countermeasures.

  • Report
    Cohen JM, Barron AS, Anderson RJ, 2014,

    Human Operational Support on UTO Lines

    , Publisher: Imperial College London

    Metro automation is an increasing trend worldwide. This study investigated the realities of operating automated lines, focused on the following key questions: What staffing levels are used by metros, and what are the pros and consof each approach? Under what circumstances do metros choose to staff all trains on linesthat are capable of unattended operations? What technology is required to enable automated operations? Do the benefits of automation outweigh the additional investment?

  • Conference paper
    Trompet M, Anderson, Richard, Graham, Daniel J, Condry, Benet al., 2014,

    Performance Benchmarking: Lessons Learned from Years of International Transit Benchmarking

    , Transportation Research Board
  • Journal article
    Moradi R, Schuster W, Feng S, Ochieng Wet al., 2014,

    A new carrier phase multipath mitigation technique for ionosphere-free combination

    , Institute of Navigation International Technical Meeting 2014, ITM 2014, Pages: 562-567

    The ionosphere layer of the atmosphere impacts the speed of electromagnetic waves such as those used by Global Navigation Satellite Systems (GNSS). If dual frequency measurements are available, the dependency of ionospheric errors on the frequency can be exploited to remove a significant fraction of these errors using the ionosphere-free (IF) combination. However, although such combination reduces the ionosphere-induced errors significantly, it also magnifies the noise and multipath errors. A new IF multipath mitigation technique is developed in this paper. In this technique, mitigation is achieved by extracting Inter Frequency carrier Multipath (IFM) errors for Global Positioning System (GPS) L1 and L2 and removing them from the IF carrier phase observation. Three test scenarios with different baselines were conducted using real data sets collected in static mode, and post processed in Real-Time Kinematic (RTK) mode. By mitigating the multipath errors in the ionosphere-free combination using the new technique developed in this paper, the horizontal Root Mean Square (RMS) error was reduced by 27% to 45% and the horizontal mean errors were reduced by 25% to 33%.

  • Journal article
    Zis T, North RJ, Angeloudis P, Ochieng WY, Bell MGHet al., 2014,

    Evaluation of cold ironing and speed reduction policies to reduce ship emissions near and at ports

    , Maritime Economics & Logistics, Vol: 16, Pages: 371-398
  • Journal article
    Ramli AR, Graham DJ, 2013,

    The demand for road transport diesel fuel in the UK: Empirical evidence from static and dynamic cointegration techniques

    , Transportation Research Part D - Transport and Environment, Vol: 26, Pages: 60-66, ISSN: 1361-9209
  • Journal article
    Li H, Graham DJ, Majumdar A, 2013,

    The impacts of speed cameras on road accidents: An application of propensity score matching methods

    , ACCIDENT ANALYSIS AND PREVENTION, Vol: 60, Pages: 148-157, ISSN: 0001-4575
  • Journal article
    Anderson R, Condry B, Findlay N, Brage-Ardao R, Li H, Condry B, Findlay N, Brage-Ardao R, Li Het al.,

    Measuring and Valuing Convenience and Service Quality: A Review of Global Practices and Challenges from Mass Transit Operators and Railway Industries

    , International Transport Forum Discussion Papers, No. 2013/16, PCED Publishing, Paris, ISSN: 2223-439X
  • Journal article
    Melo PC, Graham DJ, Brage-Ardao R, 2013,

    The productivity of transport infrastructure investment: A meta-analysis of empirical evidence

    , REGIONAL SCIENCE AND URBAN ECONOMICS, Vol: 43, Pages: 695-706, ISSN: 0166-0462
  • Journal article
    Mare DC, Graham DJ, 2013,

    Agglomeration elasticities and firm heterogeneity

    , Journal of Urban Economics, Vol: 75, Pages: 44-56

    This paper examines three key issues encountered when estimating the relationship between agglomeration and multi factor productivity (‘agglomeration elasticities’): the sorting of heterogeneous firms, the convexity of agglomeration effects, and the challenges of identifying the impact of persistent spatial differences in effective density. We use a firm-level panel containing production data together with detailed information on the geographic location of employment, covering a high proportion of the New Zealand economy. We are able to control for heterogeneity along firm, region, and industry dimensions, and to estimate separate agglomeration elasticities across industries and regions. Sorting leads to upward biased elasticity estimates but using firm fixed effects can lead to downward bias due to the highly persistent nature of agglomeration variables. Our preferred estimates control for sorting across regions and industries. Overall, we find a positive agglomeration elasticity of 0.066. Within industries and, to a lesser extent within regions, there is pronounced variation in the strength of agglomeration effects, and evidence of decreasing returns to agglomeration. High density areas attract firms that benefit most from agglomeration.

  • Conference paper
    Anderson RJ, Condry BJ, 2013,

    International Public Transport Benchmarking: Can It Be Useful?

  • Journal article
    Barron A, Melo PC, Cohen JM, Anderson RJet al., 2013,

    Passenger-Focused Management Approach to Measurement of Train Delay Impacts

    , Transportation Research Record, Vol: 2351, Pages: 46-53, ISSN: 0361-1981

    Train delay incidents have major effects on transit service reliability and on customer satisfaction. Operators have long focused efforts on preventing such incidents. While this action is important, the fact that all transit operations inevitably face some degree of delay and disruption from incidents means that operators must also dedicate attention to reducing the duration of incidents and the time to restore normal operations after incidents occur. To be able to do this, it is necessary to measure the total impact of incidents on train service and customers. This research uses data from the CoMET and Nova metro benchmarking groups to investigate the ways in which transit operators can better measure the full effects of incidents on train service and customers. The key benefit of such a passenger-focused approach is that it enables transit managers to direct resources for incident response and recovery better, as well as support the case for strategic investments. This research has shown that most operators measure and report only the frequency of incidents. Of the 22 metros interviewed, only two were able to provide detailed data to estimate the number of passengers affected by incidents. It is no coincidence that the only two metros able to provide detailed data are in fact two of the most reliable in the group.

  • Journal article
    Trompet M, Parasram R, Anderson RJ, 2013,

    Benchmarking Disaggregate Customer Satisfaction Scores Between Bus Operators In Different Cities and Countries

    Directly comparing the satisfaction of customers of urban bus operators in different cities and countries is methodologically challenging due to the different surveys used, different sample frames, different response collection methods and the possibility of cultural bias. Nonetheless, due to the importance of customer satisfaction, the members of the International Bus Benchmarking Group started a research project in 2009 to overcome these challenges. The objective was for bus operators to understand the relative performance in meeting their customer’s expectations and to be able to target those areas in which they relatively underperform. Between 2009-2012, eight to ten participating organizations annually posted identical surveys on their website homepages in the same period. This paper describes the survey and data normalization methodology developed within the International Bus Benchmarking Group that provides managers of these organizations with a comparable view of their customer satisfaction. The described methodology has been successfully tested in the bus industry but can also be applied to other industries where there is a wish to benchmark customer satisfaction amongst other national and international peers.

  • Journal article
    Li H, Graham DJ, Majumdar A, 2012,

    The effects of congestion charging on road traffic casualties: A causal analysis using difference-in-difference estimation

    , ACCIDENT ANALYSIS AND PREVENTION, Vol: 49, Pages: 366-377, ISSN: 0001-4575
  • Journal article
    Graham DJ, McCoy EJ, Stephens DA, 2012,

    Quantifying the effect of area deprivation on child pedestrian casualties by using longitudinal mixed models to adjust for confounding, interference and spatial independence

    , Journal of the Royal Statistical Society Series A-Statistics in Society, Vol: 176, ISSN: 0964-1998
  • Journal article
    Jiwattanakulpaisarn P, Noland RB, Graham DJ, 2012,

    Marginal Productivity of Expanding Highway Capacity

    , JOURNAL OF TRANSPORT ECONOMICS AND POLICY, Vol: 46, Pages: 333-347, ISSN: 0022-5258
  • Journal article
    Melo PC, Graham DJ, Noland RB, 2012,

    The effect of labour market spatial structure on commuting in England and Wales

    , JOURNAL OF ECONOMIC GEOGRAPHY, Vol: 12, Pages: 717-737, ISSN: 1468-2702
  • Conference paper
    Trompet M, Graham DJ, 2012,

    A Balanced Approach to Normalizing Bus Operational Data for Performance Benchmarking Purposes

    , 91st Transportation Research Board Annual Meeting

    Peer organizations in a performance benchmarking group are usually carefully selected based on similar characteristics such as the type of services offered, operational characteristics and density of the service area. These similarities enable organizations to compare performance once their operational data are normalized. The most commonly used normalization factors for the demand side output are passenger boardings and passenger kilometres. For the supply side output these are vehicle kilometres and vehicle hours. Through seven years of experience in the International Bus Benchmarking Group (IBBG) a better understanding of differences in service characteristics between ‘similar’ peers has been achieved. It became clear that relative performance can often not be concluded from a performance indicator normalized in one dimension. Variety in commercial speed, trip length, vehicle capacity, vehicle weight and network efficiency results in the need for a multi dimensional or balanced approach to data normalization. This paper quantifies the variety within these operational characteristics and provides a framework for benchmarking practitioners and policymakers that suggests applicable combinations of denominators for a balanced normalization process. This paper further describes how alternative normalization factors such as revenue service planning capacity kilometres and total tonne kilometres have improved comparability of Key Performance Indicators (KPIs).

  • Journal article
    Theofilatos A, Graham D, Yannis G, 2012,

    Factors Affecting Accident Severity Inside and Outside Urban Areas in Greece

    , TRAFFIC INJURY PREVENTION, Vol: 13, Pages: 458-467, ISSN: 1538-9588
  • Journal article
    Melo PC, Graham DJ, Canavan S, 2012,

    Effects of Road Investment on Economic Output and Induced Travel Demand

    , Transportation Research Record: Journal of the Transportation Research Board (In Press)
  • Conference paper
    Anderson RJ, Findlay NS, Graham DJ, 2012,


    , 91st Transportation Research Board Annual Meeting, 2012

    Data from 27 metros show that while 63% require some form of operating subsidy, levels of support vary greatly between metro operators. The ability of a metro to meet rising customer expectations and to provide a sustainable level of service quality in the medium to long term depends crucially on its funding regime and the fares policies that underpin it. Dependable funding is required to provide stable levels of renewals and enhancements. Yet, for the majority of European and American metros, in recent years fares have been decreasing in real terms, labour productivity has fallen and subsidy requirements have consequently increased at a time when public funds are increasingly scarce. The objectives of this paper are to explore the extent to which fares cover metro operating and renewals costs and the manner and degree to which any shortfalls in income are met by other commercial sources and by public funding. The paper then compares the variation in metro fare levels and how they are changing over time before discussing how fare setting policies can be improved to better reflect the true economics of urban metros. This paper argues that metros in many cities require a much more robust and principled approach to fare setting and regulation to achieve economic sustainability. In particular, fare adjustments must be applied regularly and systematically, better reflect the costs of inputs and affordability, support the imperative to renew assets and enhance service quality and, through differential pricing, more closely reflect the variable cost of travel.

  • Journal article
    Melo PC, Graham DJ, 2012,

    Testing for Labour Pooling as a Source of Agglomeration Economies: Evidence for Labour Markets in England and Wales

    , Papers in Regional Science
  • Journal article
    Molloy J, Melo PC, Graham DJ, Majumdar A, Ochieng Wet al., 2012,

    The Role of Air Travel Demand Elasticities in Reducing Aviation's CO2 Emissions: Evidence for European Airlines

    , Transportation Research Record: Journal of the Transportation Research Board
  • Journal article
    Mohammad S, Graham D, Melo P, Anderson Ret al., 2012,

    A meta-analysis of the impact of Rail Projects on Land and Property values

    The literature on land/property values demonstrates large variability in the estimated change in values arising from rail investments. This study conducts a meta-analysis on empirical estimates for 102 observations on the same. The factors that produce significant variations include the type of land use, the type of rail, rail maturity, the distance to stations, the geographical location, accessibility to other modes, methodological characteristics, and whether the impacted area is land or property. On the other hand, we observe that changes in purchase price and rent values are statistically indifferent, that there is no evidence of change in values over time nor due to the location of land/property within the city, and that including property and neighbourhood characteristics in the model do not change values significantly. Publication bias tests are performed and show that although researchers tend to report positive and negative results, they tend to be biased towards significant estimates.

  • Journal article
    Le Nechet F, Melo PC, Graham DJ, 2012,

    Transportation-Induced Agglomeration Effects and Productivity of Firms in Megacity Region of Paris Basin

    , TRANSPORTATION RESEARCH RECORD, Pages: 21-30, ISSN: 0361-1981
  • Conference paper
    Mohammad SI, Graham DJ, Melo PC, Anderson RJet al., 2012,

    A meta-analysis of the impact of rail projects on land and property values

    , 1st European Symposium on Quantitative Methods in Transportation Systems
  • Journal article
    Allport RJ, Anderson RJ, 2011,

    Managing strategic risk – the worldwide experience of metros

    , Proceedings of the Institution of Civil Engineers - Management, Procurement and Law, Vol: 164, Pages: 173-180, ISSN: 1751-4304

    <jats:p> This paper is concerned with the management of many of the world’s largest metros (mass transit railways). It describes how co-operation between operators has over 16 years led to continuous improvements in metro performance. In recent years, however, it has become clear that the complexities of metro systems are not always understood by stakeholders, and an increasingly uncertain future poses major challenges for proactive metro management. Research has concluded that the implementation of strategic risk management holds promise for future improvement, where risk is defined to include both downside impacts and opportunities. A risk guide has been developed to assist operators to implement effective practices. This paper is written to share these experiences in this sector, in the expectation that there may be lessons of wider interest. </jats:p>

  • Conference paper
    Davies G, Segal J, Condry B, 2011,

    Understanding the market for "out of normal hours" train services in Great Britain

    , European Transport Conference 2011

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