The route to growth: transport, density and productivity

SSRN Electronic Journal, 2000

Traditional program evaluation of transport investment tends to focus on relatively narrow measures of market benefit (e.g. a transport project's reductions in traveltimes that will be generated for travellers). In many cases benefit measures such as these are more than sufficient, especially when considering increments to existing transport and other infrastructure networks. However, transport infrastructure can have significant spatial effects such as expansion in effective access to markets for goods and services and an ability to achieve agglomeration and other spatial economies across those markets. Agglomeration economies in particular are inconsistently understood and often incompletely specified. This paper develops a template which categorises agglomeration effects, indicating how they arise from real-world characteristics which are counter to standard simplifying assumptions which are the basis of most traditional evaluation methods.

Transportation, 2011

The case for including agglomeration benefits within transport appraisal rests on an assumed causality between access to economic mass and productivity. Such causality is justified by the theory of agglomeration, but is difficult to establish empirically because estimates may be subject to sources of bias from endogeneity and confounding. The paper shows that conventional panel methods used to address these problems are unreliable due to the highly persistent nature of accessibility measures. Adopting an alternative approach, by applying semiparametric techniques to restricted sub-samples of the data, we find considerable nonlinearity in the relationship between accessibility and productivity with no positive effect to be discerned over broad ranges of the data. A key conclusion is that we are unable to distinguish the role of accessibility from other potential explanations for productivity increases. For transport appraisal, this implies that the use of conventional point elasticity estimates could be highly misleading.

Ersa Conference Papers, 2005

The economic evaluation of a transport project relies primarily on the impact of the project on road users. Economic benefits are calculated from a reduction in the aggregate value of time saved by the users, as well as from savings on vehicle-operation and maintenance costs, the reduction in traffic accidents, and more recently the ensuing negative environmental impacts of the project. Most often, the analysis assumes fixed demand.

2007

There is a substantial empirical literature quantifying the positive relationship between city size and productivity. The paper draws out the implications of this productivity relationship for evaluations of urban transport improvements. A theoretical model is developed and used to derive a wider cost-benefit measure that includes productivity effects. The order of magnitude of such effects is illustrated by calculations in a simple computable equilibrium model. It is argued that productivity effects, particularly when combined with distortionary taxation, are quantitatively important, substantially increasing the gains that are created by urban transport improvements.

2009

Abstract Transport investments can induce positive productivity benefits via agglomeration economies by increasing the scale and efficiency of spatial economic interactions. In assessing the 'agglomeration benefits' of transport investments we need to understand the spatial scale over which these externalities are distributed. This report is concerned with the effect of urban agglomeration on productivity and with how agglomeration externalities diminish with distance from source.

Journal of Transport Geography, 2015

Stimulating the economy is a dominant policy objective, but on what basis are decisions being taken around transport and growth? We describe how transport studies and political geography offer two related, but poorly connected, theoretical approaches purporting to explain the relationship between transport and the economy. Yet in what ways does it matter that two different world views exist? We test these questions through an empirical case study of how city and regional officials use transport in attempting to realise economic objectives. Echoing theoretical approaches based in political geography, we find officials own reasoning places emphasis on supply side improvements, especially connectivity within regions and on a high quality urban environment hoped to attract high GVA jobs. The decision-support tools are not well aligned to this reasoning, focussing on time savings and the justification of the value for money of proposed schemes relative to other investments in the region and nationally. In contrast to much theoretical work on competitiveness, employment growth is treated as exogenous with less emphasis given to which areas win and lose in the region. It is competition between weaker regional towns and cities that is prominent in officials discourse Such a gap between the thinking by officials, and the types of available transport investment decisionsupport tools, is of international significance. Given the centrality of the economy to where and what we invest in, the paper suggests a need for better knowledge about the efficacy of urban realm and other supply side improvements on job creation and on the influence of local autonomy in decision-making on investment selection and outcomes.

Transportation Research Record: Journal of the Transportation Research Board, 2011

Papers in Regional Science, 2005

The economic evaluation of a transport project relies primarily on the impact of the project on road users. Economic benefits are calculated from a reduction in the aggregate value of time saved by the users, as well as from savings on vehicle-operation and maintenance costs, the reduction in traffic accidents, and more recently the ensuing negative environmental impacts of the project. Most often, the analysis assumes fixed demand.

This paper explores the land transformation process and growth pattern emerging in the functional urban regions of Europe with particular attention paid to growth impacts on peri-urban areas. The process is considered in the light of the growth pattern of selected Plurel Regions which is analysed based upon international economic and social statistical evidence. Provision of transport infrastructure as a critical determinant of growth pathways will be examined.

National Transport Policy and Cities: Key policy interventions to drive compact and connected urban growth, 2019

Thriving cities – where people can easily connect with one another and with jobs, services, and amenities – are essential to economic prosperity. With the world’s urban population expected to double by 2050, cities need to be built and run in ways that maximise access to opportunities without increasing carbon emissions, pollution, and congestion. Smart transport policy has a key part to play in laying the foundations for better urban structures, boosting public transport use, making it safe and easy to walk or cycle, and discouraging private car use. This paper explores the wealth of options available to national transport policy-makers who wish to support more compact and connected urban development, and provides clear inputs on how to prioritise, broadening the focus from facilitating movement, to achieving true accessibility. It outlines different types of transport policy instruments and governance reforms, and examines 21 widely discussed interventions – including five that global experts identified as particularly effective for making cities more accessible. It ends with guiding principles for choosing and implementing the options best suited to each national context. Transport policy is typically administered by dedicated transport ministries. Although it is usually separate from spatial planning, it directly affects urban development by determining the cost of travel between places and the quality of local environments. Policy-makers recognise these impacts, but transport departments’ narrow remit – to facilitate movement – may lead them to make choices that increase urban sprawl and worsen congestion, making cities less accessible.

Research in Transportation Business & Management, 2021

This paper explores whether the benefits from major urban transport spending increases are likely to differ greatly, depending on whether that spending prioritises light rail, a mode with growing interest and several new services recently developed in Australia, major road network improvement or provision of additional bus services. It does this through a series of case studies based on Sydney, using MetroScan, an integrated transport and land use strategic model system. MetroScan is the most sophisticated strategic integrated land use, transport and economic system evaluation model in Australia, with the capability of exploring dynamic interactions between transport improvements, residential locations and job locations, among other things. We specifically focus on the impacts of major transport initiatives on reducing risks that people will be socially excluded because of poor mobility opportunities.

2001

In this study we develop an integrated econometric and CGE modelling framework for transport projects and transport policies at the European level by integrating network, regional economic and macro-economic impacts. The paper presents the formal structure of the integrated econometric and CGE modelling framework, explains the calibration and applies it to the policy evaluation. The effects of infrastructure investments are modelled by simulating trade cost changes in a comparative static analysis, using estimates of trade cost changes due to new infrastructure links, obtained from a transport network model. By performing a systematic and quantitative analysis of the spatial, network and socio-economic impacts of transport investments and policy and carrying out scenario simulations we improve the under-standing of the impact of transportation policies on short- and long-term spatial development in the EU.

Journal of the Royal Statistical Society Series A: Statistics in Society, 2019

SummaryAgglomeration-based arguments citing Dutch and German city regions have been a primary driver in advocating intercity transport strategies in the north of England. We adopt an allometric urban model investigating the applicability and transferability of these transport-led agglomerative strategies promoted to address England’s regional economic underperformance. This is undertaken through a comparative study of the size–cost performance balance of three city regions and the overall urban networks in the Netherlands and Germany, and England and Wales by using city units defined at different spatial scales. Although our results support a case for better mobility and transport comparing the three urban networks regardless of the spatial scales, comparisons of specific city regions indicate a more nuanced interplay of productivity, mobility infrastructure and urban density.

1997