Toll Road Demand Forecasting
Understanding Toll Road Demand
VLC understands each of the elements that contribute to forecasting traffic demand on toll roads – from forecasts of future population and land use from which travel demands are derived, to congestion levels on competing and feeder roads and the travel time savings provided by the toll road into the future. All of these elements are embodied within the Zenith strategic travel models that underpin our forecasting capability.
In each of Australia’s urban regions, VLC maintains accurate and current information about the most likely projections of demographic and land use change, as well as committed and planned investments in transport infrastructure. In assessing forecast risks for each toll road, we also test the impact of alternative scenarios of urban development and of key network improvements on traffic forecasts using the Zenith model.
Key Success Factors
In recent years, several Australian toll road procurements have failed, in-part due to traffic falling short of volumes forecast during the early years of operation, despite models being well calibrated against observed traffic counts.
VLC believes the most important factors in accurate estimates of early demand are recognising the different nature of travel demands throughout the day and the consequence for travel times across the road network, as well as characterising each market and their willingness-to-pay for the travel time saving offered by the toll road.
The Zenith models include a sophisticated algorithm for traffic assignment that considers the willingness of each market segment to pay for the travel time savings offered. This applies not only to the choice between tolled and untolled routes, but also between toll roads – a feature that is becoming increasingly critical as the scale of the toll road network expands in Australia’s east coast capital cities.
A Record of Accuracy
VLC has an unmatched history of accurately predicting the demand of toll roads. In 2003, the toll road forecasting capabilities of the Zenith models were significantly upgraded as part of the EastLink project in Melbourne. Zenith has since been used to forecast a number of toll roads (prior to opening). These include:
- Lane Cove Tunnel - VLC estimate 60,000 (approximately 60,000 actual)
- Cross City Tunnel - modelled 30,000 (approximately 33,000 actual)
- EastLink - 6% high
- Clem7 - 34,000 modelled (26,000 actual)
- Go Between Bridge - 15,500 modelled (14,000 actual)
- Airport Link - 53,000 modelled (50,000 actual)