Urban transport infrastructure plays a key role in the Australian economy. It facilitates the transport of people and goods, directly impacting the daily lives of the three-quarters of Australia's population who live in our largest cities. Meeting the connectivity challenges that our nation faces will require governments to ensure optimum service delivery outcomes in the urban transport sector.
For the urban transport component of the Audit, the national-level top-down economic analysis used for the other sectors, which is based on national accounts and industry data, was complemented by bottom-up analysis based on detailed transport modelling for the six largest capital cities.
This modelling, undertaken by Veitch Lister Consulting,161 provides a rich source of information about transport journeys across all modes and purposes for the six metropolitan regions. This includes data on the number and mode of journeys by origin and destination, and by key corridors.
For the road component of these corridors, the modelling includes capacity measures such as traffic volume compared to capacity (V/C) and delay time.
Passengers on Australia's public transport networks experience congestion in two forms: delays to services, and overcrowding. Delays to bus and tram services are captured in the modelling of urban roads. Delays on the rail networks, e.g. as a result of unreliable services or being unable to board an overcrowded train, were not modelled. Accordingly, estimates of the cost of road delay may be understated, e.g. where unreliable or delayed train services cause some travellers to shift from using trains to driving a car.
However, the modelling does identify passenger loads on public transport, and therefore potential overcrowding (especially the potential for so-called 'crush loads'). Details are available in the reports by Veitch Lister Consulting, and summarised in the relevant state/territory chapters of this report.
This provides a detailed view of where urban transport activity is located in each city, by mode, and by time of day. When combined with projected population growth, spatial distribution of that growth, and spatial distribution of employment and other trip generators, the model can project a similarly detailed view of the location of urban transport activity, by mode and by time of day, at a future point in time.
For the Audit, Veitch Lister modelled urban transport activity in 2031, based on the Audit's population projections (Australian Bureau of Statistics (ABS) Series B), with spatial distributions that take account of current state/ territory strategic plans.
The modelling assumes projected demand is addressed only by the existing (2014-15) network, as well as projects currently under construction or for which a budget commitment has been made. By including only those projects with firm budget commitments, the Audit aims to clearly show where demand is projected to grow in excess of supply. Including other potential projects which are not currently funded would be misleading as it would show future demand being addressed by future capacity which may not end up being provided. This acknowledges the likelihood that, in the absence of a shift in taxation and/ or expenditure priorities (or some shift to user charging), governments will struggle to fund the development of a large portfolio of new projects. Choices will have to be made.
The traffic data generated by Veitch Lister has then been modelled by ACIL Allen Consulting to estimate the value-add and delay cost for each corridor, based on the number and mode of journeys. This approach takes account of the different value attributable to different modes. For example, congestion on a particular road might impose the same time delay on a large truck and a small car, but the cost of that delay is different for each vehicle when factors such as capital, operating and opportunity costs are taken into account.
The modelling provides one method of measuring and projecting demand for transport infrastructure. State governments may have utilised other data, and different methods of analysis, to inform identification of infrastructure priorities. For further information on the assumptions, included projects and methodology applied in the model, refer to the supporting documentation by Veitch Lister Consulting.
This analysis facilitates identification of the corridors with the highest levels of economic activity, and the corridors in which capacity constraints and/or delays impose the highest economic cost. Given the absence of rail delay cost from the model, the projected delay cost for a corridor is at best an approximation. However, rail delay cost is unlikely to represent more than a small proportion of total delay cost for most corridors. As such, road delay cost is a reasonable indicator of overall delay cost for most corridors.
This approach allows comparison of key corridors across different cities on a consistent basis. It details the cost of congestion in the Audit base year, showing pressure points in the system at that time. It then makes a projection of the cost of capacity constraints in 2031 if our cities grow as projected, without any additional urban transport capacity. This indicates where interventions may have the greatest effect. However, it does not indicate what type of intervention would be most effective - this will require further detailed analysis of individual corridors taking into account, for example, whether current or increased rail capacity in a particular corridor might be able to absorb part of a projected increase in passenger demand.
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161. Veitch Lister Consulting (2014a)