TransPosition was engaged by Synergies to provide input to the development of the database to be used for the Department of Main Roads (DTMR) Cost Mobility Tool. Using the South East Queensland (SEQ) 4S model, TransPosition created the database to include:
- Direct transport cost (public transport fares, toll prices, and parking costs)
- Number of person trips
- Total kilometres travelled by each transport mode (active, private vehicles, bus, ferry, train, rapid transport)
- For private vehicles and bus use, total kilometres travel on each road type
- The utilisation of the road and public transport (PT) network
In discussion with Synergies, many different sensitivity variables were prepared, including adjustments to PT fare pricing, PT frequency, vehicle occupancy, distance based driving cost (equivalent to changes in fuel pricing), hourly road usage charge.
One of the custom outputs generated for this project was a measure of road utilisation for each road hierarchy and public transport option. The utilisation output aimed to quantify the network use. For road type the utilisation was determined by the volume on the road divided by the road capacity. These levels range between 0%, uncongested, and 100%, where traffic volumes are at maximum capacity.
Due to the different restrictions and structure of private vehicles and public transport services (e.g., cars can have near to unlimited number of service each day, while PT has a fixed number), the utilisation of each is defined differently. For the PT network the utilisation of each service is defined as the number of passengers using the service divided by the capacity times the number of service.
Modelling scenarios were created with different factors applied to the cost of driving (by distance) and the public transport fares. The results that these changes had to the utilisation of the 2031 SEQ network can be seen in the figures below.
When the cost of travel is increased the utilisation of the road network drops and the use of public transport increases, particular the use of trains
Adjustments to the PT fares dramatically changes the amount PT is utilised, if the fare doubles the use of PT halves