For the urban transport component of the Audit, the 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 major capital cities.
This modelling provides detailed information about trips within these cities by origin/destination, and by corridor, in 2011. It takes account of projected population and employment growth and spatial distribution to project demand for trips, also by origin/destination and corridor, in 2031.
The model includes detailed information about capacity, showing where demand is projected to grow in excess of supply. For road corridors it quantifies the cost of delay, showing where interventions will likely provide the biggest economic return and serves as a useful indicator of which corridors warrant further study.