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  • Journal article
    Carbo Martinez J, Graham D, Anupriya A, Casas D, Melo Pet al., 2018,

    Evaluating the causal economic impacts of transport investments: evidence from the Madrid-Barcelona high speed rail corridor

    , Journal of Applied Statistics, ISSN: 0266-4763

    This paper evaluates economic impacts arising from the introduction of high-speed rail (HSR) between Madrid and Barcelona. Using difference-in-differences estimation we estimate an average treatment effect for provinces with stops on the HSR line of 2.4% for economic output, 3.3% for numbers of firms, and 1.1% for labour productivity. We complement our DID results with a synthetic control analysis for Lleida and Tarragona, two provinces that we argue were assigned HSR stations largely due to their incidental location. We find that both the number of firms and labour productivity are substantially higher in these provinces than in their synthetic counterparts.

  • Journal article
    Barron A, Canavan S, Cohen J, Anderson Ret al., 2018,

    Operational impacts of platform doors in metros

    , Transportation Research Record, Vol: 2672, Pages: 266-274, ISSN: 0361-1981

    Platform doors are increasingly installed by metros, primarily to improve safety. However, they have the potential for both positive and negative operational impacts, mostly by affecting dwell times at stations. Using data from the CoMET and Nova international metro benchmarking consortia of 33 metro systems, this paper seeks to understand and quantify these operational impacts. Overall, platform doors have a net negative impact on dwell times, leading to between 4 and 15 seconds of extra time per station stop. This is due to additional time for the larger doors to open and close slower passenger movements due to the additional distance between platforms and trains and, most importantly, extended departure delays after both sets of doors are closed caused by the need to ensure safety (that no one is trapped in the gap between the two sets of doors). This is a particular problem in mainland China, where metros conduct manual safety checks that require drivers to step out of trains onto platforms. However, despite longer dwell times, platform doors have a net positive impact on metro operations, largely due to the many safety benefits that also reduce delays and thereby improve service performance. There are also potential benefits regarding energy and ventilation. To mitigate the negative impacts, metros should seek to refine procedures and improve technology to reduce dwell time delays caused by platform doors. Reducing or eliminating these extra delays are essential to delivering efficient service and maximum capacity, provided that safety can be assured.

  • Journal article
    Canavan S, Graham D, Anderson R, Barron Aet al., 2018,

    Urban metro rail demand: evidence from dynamic generalised method of moments (GMM) estimates using panel data

    , Transportation Research Record, Vol: 2672, Pages: 288-296, ISSN: 0361-1981

    This paper estimates elasticities of demand for metro service with respect to fares, income, quality of service, population and network length. Data for 32 world metro systems covering the period from 1996 to 2015 are analysed within a dynamic panel data specification. Three key contributions are made. First, we collate a database for estimation that is more extensive than that used in previous studies. Second, the quality of the data we have available allows us to more accurately represent quality of service than has been possible previously. And lastly, we estimate and compare two different measures of demand. Our analysis finds a statistically significant negative fare elasticity of -0.25 in the long run for a passenger km specified model and -0.4 in the long run for a passenger journeys specified model, and a positive long run income elasticity of 0.17 and 0.18 for the passenger km and passenger journey models respectively. Regarding quality of service we find positive long run elasticities of 0.56 and 0.47 for the passenger km and passenger journey models respectively. Income levels, population and the size of the network are also found to be statistically significant and positive in nature. The results suggest passenger km and passenger journeys will increase more in response to changes in service (here represented by increased capacity) than to changes in fares, with the difference in elasticities of service and fares being more pronounced for passenger km.

  • Journal article
    Trompet M, Anderson RJ, Graham DJ, 2018,

    Improved understanding of the relative quality of bus public transit using a balanced approach to performance data normalization

    , Transportation Research Part A: Policy and Practice, Vol: 114, Pages: 13-23, ISSN: 0965-8564

    In order for bus operators and/or their respective authorities to understand where service quality can improve, it is useful to systematically compare performance with organizations displaying similarities in types of services offered, operational characteristics and density of the service area. These similar characteristics enable peer organizations to benchmark performance once their operational data are normalized for differences in scale of operations. 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 twelve years of experience in the International Bus Benchmarking Group (IBBG) a better understanding of differences in service characteristics between ‘similar’ peers has been achieved, which highlight a challenge for the interpretation of normalized performance. It became clear that relative performance should often not be concluded from performance indicators normalized in a single dimension. Variety between peers in commercial speed, trip length, vehicle planning capacity, vehicle weight and network efficiency result in the need for a bi-dimensional or balanced approach to data normalization. This paper quantifies the variety within these operational characteristics and provides examples of the interpretation bias this may lead to. A framework is provided for use by bus organization management, policymakers and benchmarking practitioners that suggests applicable combinations of denominators for a balanced normalization process, leading to improved understanding of relative performance.

  • Journal article
    Barzin S, D'Costa S, Graham DJ, 2018,

    A pseudo - Panel approach to estimating dynamic effects of road infrastructure on firm performance in a developing country context

    , Regional Science and Urban Economics, Vol: 70, Pages: 20-34, ISSN: 0166-0462

    To overcome the absence of true firm-level data, we provide evidence that the use of pseudo-panels based on aggregated data can correctly identify production function parameters. We construct a pseudo-panel of Colombian manufacturing firms for the years of 2000–2009 to study the effects of transportation infrastructure on firm performance in a developing country and find elasticities of output with respect to road infrastructure ranging from 0.13 to 0.15 per cent. This confirms that roads are important for private output growth and, as our results are larger than those reported in the literature for developed countries, that transportation infrastructure is relatively more important for the economy of developing countries. We also identify a one-year time lag with which firms' outputs react to road stock changes. This could be indicative of firms requiring time to adjust their production to road changes. We furthermore identify that the effect of road infrastructure is particularly large for heavy manufacturing industries. Moreover, we investigate the regional heterogeneity of the role of transportation infrastructure for firms' output growth. Our results are robust to different econometric concerns. We additionally provide Monte Carlo simulations to support the validity of pseudo-panels in the context of firm-level data.

  • Journal article
    Melo PC, Graham DJ, 2018,

    Transport-induced agglomeration effects: Evidence for US metropolitan areas

    , Regional Science Policy and Practice, Vol: 10, Pages: 37-47

    While the interaction between transport and agglomeration economies is widely accepted, there is insufficient research attempting at a direct empirical quantification. Using a balanced panel dataset for US metropolitan areas, we estimate a system of simultaneous equations to measure the indirect effect of urban agglomeration economies which arises through transport provision. Our findings suggest that public transit reinforces the effect of urban agglomeration, whereas road lane miles appear to weaken it. The results highlight the importance of public transit in supporting positive urban agglomeration externalities.

  • Journal article
    Horcher D, Graham DJ, 2018,

    Demand imbalances and multi-period public transport supply

    , Transportation Research Part B: Methodological, Vol: 108, Pages: 106-126, ISSN: 0191-2615

    This paper investigates multi-period public transport supply, i.e. networks in which capacity cannot be differentiated between links and time periods facing independent but nonidentical demand conditions. This setting is particularly relevant in public transport, as earlier findings on multi-period road supply cannot be applied when the user cost function, defined as the sum of waiting time and crowding costs, is nonhomogeneous. The presence of temporal, spatial and directional demand imbalances is unavoidable in a public transport network. It is not obvious, however, how the magnitude of demand imbalances may affect its economic and financial performance. We show in a simple back-haul setting with elastic demand, controlling for total willingness to pay in the network, that asymmetries in market size reduce the attainable social surplus of a service, while variety in maximum willingness to pay leads to higher aggregate social surplus and lower subsidy under efficient pricing. The analysis of multi-period supply sheds light on the relationship between urban structure, daily activity patterns, and public transport performance.

  • Journal article
    Horcher D, Graham DJ, Anderson RJ, 2017,

    The economics of seat provision in public transport

    , Transportation Research Part E: Logistics and Transportation Review, Vol: 109, Pages: 277-292, ISSN: 1366-5545

    Seated and standing travelling imply significantly different experience for public transport users. This paper investigates with analytical modelling and numerical simulations how the optimal seat supply depends on demand and supply characteristics. The paper explores the implications of seat provision on the marginal cost of travelling as well. In crowded conditions, we distinguish two types of external costs: crowding density and seat occupancy externalities. We derive, using a realistic smart card dataset, the externality pattern of a metro line, and identify the distorting role of the occupancy externality that makes the welfare maximising fare disproportionate to the density of crowding.

  • Conference paper
    Achurra Gonzalez PE, Angeloudis P, Hu S, Zavitsas K, Graham DJet al.,

    Modelling the impact of infrastructure developments on the resilience of intermodal container transport networks: One-Belt-One-Road Case study

    , 7th International Conference on Logistics and Maritime Systems
  • Journal article
    Horcher D, Graham DJ, Anderson RJ,

    The economic inefficiency of travel passes under crowding externalities and endogenous capacity

    , Journal of Transport Economics and Policy, ISSN: 0022-5258
  • Journal article
    Piner D, Condry B, 2017,

    International best practices in managing unplanned disruption to suburban rail services

    , Transportation Research Procedia, Vol: 25, Pages: 4403-4410, ISSN: 2352-1465

    This paper analyses the management approaches of passenger railways towards unplanned disruption of service, and provides examples of best practices from suburban railways around the world.The priority of participating railways is to return service to normal as quickly as possible and provide at least some services on core routes. The greatest challenges include the provision of accurate and consistent information, arranging alternative transport and the need to make fast decisions.The paper highlights a number of best practices, such as the use of ‘Central Crisis Rooms’ as the focal point for all disruption management, including decision making, CCTV coverage of affected areas and liaison with alternative transport providers.

  • Report
    Mundy D, Trompet M, Cohen J, Graham Det al., 2017,

    The Identification and Management of Bus Priority Schemes; A Study of International Experiences and Best Practices

    Priority measures for bus services can deliver significant benefits both for passengers and the operator. For example, green light priority or the conversion of road space to dedicated bus lanes can deliver journey time (variability/predictability) benefits thereby improving both quality of service and operational efficiency. This study investigates how bus priority schemes are identified, selected and managed in 14 different cities across Asia, Australia, Europe and North America. The study reviews the decision making processes, including associated input from bus operators, involved in identifying necessary bus schemes. The study provides examples of succesful and unsuccessful bus priority schemes and methods of bus priority enforcement are explored to establish interesting and successful ways to ensure bus priority measures can be effective. This report may be useful to different stakeholders experiencing difficulties with bus priority selection, implementation and management, such as city/ borough governments, road authorities, bus operators, passenger groups, police, and other organisations.

  • Conference paper
    Achurra Gonzalez PE, Angeloudis P, Zavitsas K, Niknejad SA, Graham DJet al.,

    A Quantitative Framework for Assessment of Network Vulnerability in Liner Shipping Networks

    , Transportation Research Board 96th Annual Meeting
  • Journal article
    Morse L, Trompet M, Barron A, Graham DJet al., 2017,

    Development of a key performance indicator system to benchmark relative paratransit performance

    , Transportation Research Record-Series, Vol: 2650, Pages: 1-8, ISSN: 0361-1981

    The Americans with Disabilities Act of 1990 prohibits discrimination against people with disabilities. US transit agencies are therefore required to offer services to eligible customers that complement the mobility opportunities provided to the general public on fixed-route public transit. While these paratransit services are necessary and just, they represent a proportionally large cost to agencies: approximately eight times the cost per boarding compared to fixed-route bus service. To be able to identify opportunities for (cost) efficiencies, and to further improve the quality of paratransit services offered, the twenty agencies of the American Bus Benchmarking Group (ABBG) decided to benchmark their relative performance in paratransit management and operations. To ensure comparability of agencies’ performance and hence ensure the usefulness of the benchmarking program, a key performance indicator system was developed and associated data items were defined in detail. The scope of this system went beyond the data already provided to the National Transit Database, both in amount and granularity of data collected, as well as the detail of definitions. This paper describes the challenges, respective solutions, and other lessons identified during four years of paratransit benchmarking development led by Imperial College London, the ABBG facilitators. The paper provides transit agencies and authorities as well as benchmarking practitioners and academics an opportunity to apply these lessons for the further benefit of paratransit services and their customers around the U.S.

  • Journal article
    Li H, Graham DJ, Liu P, 2016,

    Safety effects of the London cycle superhighways on cycle collisions

    , Accident Analysis & Prevention, Vol: 99, Pages: 90-101, ISSN: 0001-4575

    This paper evaluates the effects of the London Cycle Superhighways (CS) on cycle collisions. A total of 45 CS segments and 375 control segments are observed for a period of 8 years in London. Variables such as road characteristics, crash history and socio-economic in formation are included in the data set. Traffic characteristics Including traffic volume, cycle volume and traffic speed are obtained from Department for Transport. We first estimate the safety effects on the CS routes using Empirical Bayes methods. Then propensity score matching methods are also applied for comparison. The introduction of cycle superhighways caused cycling traffic volumes to increase dramatically along CS routes with no significant impacts on collision rates. Our models find that the increase in traffic was associated with a rise in annual total cycle collisions of around 2.6 per km (38% in percentage). However, when we re-estimate the effects based on cycle collision rates rather than levels, our results also show that the CS routes are not more dangerous or safer than the control roads. Among the four CS routes, CS3 performs the best in protecting cyclists with a large proportion of segregated lanes whilst the cyclists have to share the lanes with motorists on other routes. It is recommended that consistent safety designs shouldbe applied on all CS routes for a safer cycling environment.

  • Journal article
    Horcher D, Graham DJ, Anderson RJ, 2016,

    Crowding cost estimation with large scale smart card and vehicle location data

    , Transportation Research Part B - Methodological, Vol: 95, Pages: 105-125, ISSN: 0191-2615

    Crowding discomfort is an external cost of public transport trips imposed on fellow passengers that has to be measured in order to derive optimal supply-side decisions. This paper presents a comprehensive method to estimate the user cost of crowding in terms of the equivalent travel time loss, in a revealed preference route choice framework. Using automated demand and train location data we control for fluctuations in crowding conditions on the entire length of a metro journey, including variations in the density of standing passengers and the probability of finding a seat. The estimated standing penalty is 26.5% of the uncrowded value of in-vehicle travel time. An additional passenger per square metre on average adds 11.9% to the travel time multiplier. These results are in line with earlier revealed preference values, and suggest that stated choice methods may overestimate the user cost of crowding. As a side-product, and an important input of the route choice analysis, we derive a novel passenger-to-train assignment method to recover the daily crowding and standing probability pattern in the metro network.

  • Journal article
    Li H, Graham DJ, 2016,

    The Heterogeneous Treatment Effects of Speed Cameras on Road Safety

    , Accident Analysis & Prevention, Vol: 97, Pages: 153-161, ISSN: 0001-4575

    This paper analyses how the effects of fixed speed cameras on road casualties vary across sites with different characteristics and evaluates the criteria for selecting camera sites. A total of 771 camera sites and 4787 potential control sites are observed for a period of 9 years across England. Site characteristics such as road class, crash history and site length are combined into a single index, referred to as a propensity score. We first estimate the average effect at each camera site using propensity score matching. The effects are then estimated as a function of propensity scores using local polynomial regression. The results show that the reduction in personal injury collisions ranges from 10% to 40% whilst the average effect is 25.9%, indicating that the effects of speed cameras are not uniform across camera sites and are dependent on site characteristics, as measured by propensity scores. We further evaluate the criteria for selecting camera sites in the UK by comparing the effects at camera sites meeting and not meeting the criteria. The results show that camera sites which meet the criteria perform better in reducing casualties, implying the current site selection criteria are rational.

  • Journal article
    Cohen JM, Barron AS, Anderson RJ, Graham DJet al., 2016,

    Impacts of Unattended Train Operations (UTO) on Productivity and Efficiency in Metropolitan Railways

    , Transportation Research Record-Series, Vol: 2534, Pages: 75-83, ISSN: 0361-1981

    Urban metro subway systems (metros) around the world are choosing increasing levels of automation for new and existing lines: the global length of metro lines capable of unattended train operation (UTO) is predicted to triple in the next 10 years. Despite significant investment in this technology, empirical evidence for the financial and service quality impacts of UTO in metros remains scarce. This study used questionnaires and semistructured interviews with the Community of Metros and Nova Group benchmarking groups to assemble emerging evidence of how automation affected costs, staffing, service capacity, and reliability. The results from an analysis of data from 23 lines suggested that UTO could reduce staff numbers by 30% to 70%, with the amount of wage cost reduction depending on whether staff on UTO lines were paid more. On the basis of the experience of seven metros, the capital costs of lines capable of UTO were higher, but the internal rate of return had been estimated by two metros at 10% to 15%. Automated lines were capable of operating at the highest service frequencies of up to 42 trains per hour, and the limited available data suggested that automated lines were more reliable. The findings indicated that UTO was a means to a more flexible and reliable operating model that could increase metro productivity and efficiency. The study identified important work needed to understand the impacts of UTO and identify where statistical analyses would add value once sufficiently large data sets became available.

  • Journal article
    Canavan S, Graham D, Melo P, Anderson R, Barron A, Cohen Jet al., 2016,

    The Impacts of Moving Block Signalling on Technical Efficiency: An Application of Propensity Score Matching on Urban Metro Rail Systems

    , Transportation Research Record, Vol: 2534, Pages: 68-74, ISSN: 0361-1981

    This study tested the effect of introducing moving-block signaling on the technical efficiency of urban metro rail systems. The study used a panel data set of 27 urban metro systems across 20 countries for 2004 to 2012. When moving-block signaling was considered as a treatment, the effect of the associated benefits on output efficiency levels was able to be measured. Stochastic frontier analysis was employed to estimate technical efficiencies for each metro, and then propensity score matching was applied to evaluate the effect of the type of signaling on technical efficiency. The study allowed the selection of appropriate reference groups and accounted for confounding factors. The study is novel in its provision of empirical evidence of this nature. The results indicate that the technical efficiency of a metro can be improved by 11.5%.

  • Conference paper
    Yannis G, Dragomanovits A, Laiou A, Richter T, Ruhl S, La Torre F, Domenichini L, Graham D, Karathodorou N, Li Het al., 2016,

    Use of Accident Prediction Models in Road Safety Management – An International Inquiry

    , 6th Transport Research Arena, Publisher: Elsevier BV, Pages: 4257-4266, ISSN: 2352-1465
  • Journal article
    Graham DJ, Li H, 2016,

    Quantifying the causal effects of 20 mph zones on road casualties in London via doubly robust estimation

    , Accident Analysis & Prevention, Vol: 93, Pages: 65-74, ISSN: 0001-4575

    This paper estimates the causal effect of 20 mph zones on road casualties in London. Potential confounders in the key relationship of interest are included within outcome regression and propensity score models, and the models are then combined to form a doubly robust estimator. A total of 234 treated zones and 2844 potential control zones are included in the data sample. The propensity score model is used to select a viable control group which has common support in the covariate distributions. We compare the doubly robust estimates with those obtained using three other methods: inverse probability weighting, regression adjustment, and propensity score matching. The results indicate that 20 mph zones have had a significant causal impact on road casualty reduction in both absolute and proportional terms.

  • Conference paper
    Achurra Gonzalez PE, Angeloudis P, Zavitsas K, Niknejad SA, Graham DJet al.,

    Attacker-defender modelling of transport vulnerability in maritime logistics corridors

    , 2nd International Workshop on Maritime Flows and Networks
  • Journal article
    Karathodorou N, Condry BJ,

    Choosing Optimal Reliability Measures for Passenger Railways: Different Measures for Different Purposes

    , Transportation Research Record, ISSN: 0361-1981

    Reliability is one of the top factors influencing customer satisfaction with passenger rail services. It affects the level of demand for the service as passengers place a large negative value on delays. This matters to service providers, as it drives the fare revenue, and to policy makers as it influences mode share. This paper comprises a review of literature on reliability measurement in public transport, the results of a global survey of suburban rail operators and an assessment of the value of specific reliability measures. Reliability measures are typically required for three distinct purposes: internal measurements to manage the service, reporting to governments/authorities or franchisors for regulatory purposes and external reporting to customers and the media. Different measures may be optimal for each of these purposes and careful consideration is required for their definition and use. However, most railways surveyed chose their reliability measures either based on regulatory obligations or simply because these were used elsewhere.

  • Conference paper
    Horcher D, Graham DJ,

    Crowding and the marginal cost of travelling under second-best capacity provision

    , International Transport Economics Association Annual Conference

    The classic economic theory of capacity optimisation in public transport suggests that the welfare maximising frequency and vehicle size increase with demand, and therefore the optimal occupancy rate may not dependent on demand; crowding can be internalised through capacity adjustment. On the other hand, empirical studies show that the crowding externality does contribute significantly to the social cost of public transport usage in large metropolitan areas. This paper presents a theoretical framework that explains why rational second-best capacity provision may lead to a wide range of demand dependent crowding levels under economies of vehicle size, infrastructure constraints and demand fluctuations. We derive the marginal external waiting time, crowding and operational costs of travelling for second-best scenarios, and explore the resulting subsidy rates. Thus, we take an important step towards the full understanding of optimal demand and crowding dependent pricing in public transport.

  • Report
    Horcher D, Graham DJ, Anderson RJ, 2016,

    Merging smart card data and train movement data: How to assign trips to trains?

    , Merging smart card data and train movement data: How to assign trips to trains?

    This report explains the assignment method applied to link trips compiled in smart card data to train movements recorded in the signalling system. Particular attention has been paid to (1) origin-destination pairs with multiple potential route options, (2) peak-hour trips delayed by di culties in boarding crowded trains at the origin station, and (3) trips originating or ending on rail lines not included in the train movement dataset.In the current version of this paper the metro network on which the method has been applied is anonymised.

  • Journal article
    Melo PC, Graham DJ, Levinson D, Aarabi Set al., 2016,

    Agglomeration, accessibility and productivity: evidence for large metropolitan areas in the US

    , Urban Studies, Vol: 54, Pages: 179-195, ISSN: 1360-063X

    This paper estimates the productivity gains from agglomeration economies for a sample of the largest metropolitan areas in the United States using measures of urban agglomeration based on employment density and employment accessibility. The latter is a more accurate measure of economic proximity and allows testing for the spatial decay of agglomeration effects with increasing travel time. We find that the productivity gains from urban agglomeration are consistent between measures, with elasticity values between 0.07 and 0.10. The large majority of the productivity gains occur within the first 20 minutes, and do not appear to exhibit significant nonlinearities.

  • Journal article
    Achurra-Gonzalez PE, Novati M, Foulser-Piggott R, Graham DJ, Bowman G, Bell MGH, Angeloudis Pet al., 2016,

    Modelling the impact of liner shipping network perturbations on container cargo routing: Southeast Asia to Europe application

    , Accident Analysis & Prevention
  • Conference paper
    Horcher D, Graham DJ,

    The dark side of travel passes: Wrong incentive in crowding

    , Transportation Research Board 95th Annual Meeting, Washington D.C.
  • Conference paper
    Horcher D, Graham DJ, Anderson R,

    The link between crowding pricing and seat supply in public transport

    , Transportation Research Board 95th Annual Meeting, Washington D.C.
  • Journal article
    Brage-Ardao R, graham DJ, anderson RJ, 2015,

    Determinants of Rolling Stock Maintenance Cost in Metros

    , Proceedings of the Institution of Mechanical Engineers Part F -Journal of Rail and Rapid Transit, Vol: 230, Pages: 1487-1495, ISSN: 0954-4097

    This study examines the economies of scale and the determinants of rolling stock maintenance costs for 24 urban rail transit operators. The estimates reveal significant returns to scale in maintenance for both per car and per car kilometre. The econometric analysis also provides statistically significant cost elasticities for wages and staff hours, suggesting substitution effects between factors. Staff outsourcing is found to significantly decrease costs, whereas higher levels of fleet availability at the peak and rolling stock failures increase it. The effect of the age of rolling stock and the network is negligible on rolling stock maintenance costs; however, the analysis reveals a downward trend in rolling stock costs among the metros in the CoMET and Nova consortia.

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