Autonomous Vehicles

Autonomous vehicles (AVs) are an emerging technology that is likely to have significant impacts on travel behaviour and road network operations in the medium to long term. The following paper was presented at the AITPM National Conference 2015 and won the award for best paper in the Transport and Land Use Modelling session. The paper addresses current progress and direction for autonomous vehicles, what this could mean for the future of transport and the possible analytical approaches to addressing these impacts. It also includes some initial modelling of autonomous vehicle impacts in Brisbane, using TransPosition’s 4S Model. Finally, some comments are made on the likely long term impacts on urban form.

Autonomous Vehicles - What Could This Mean For The Future Of Transport?

Since the 2015 AITPM Conference TransPosition has done a lot of work with the Queensland Department of Transport and Main Roads to enhance the modelling of autonomous vehicles and look at various other issues. Some of this work is included in the paper below which was presented at the 2016 TRB ITM Conference in Denver, Colorado. The focus of the new work has been researching the likely uptake rates for autonomous vehicles and building a model which determines what percentage of the fleet will be fully AV by a certain year. In addition to this, extra capability has been added to the model which allows the issue of shared autonomous vehicles (autonomous taxis) to be addressed. Single-occupant shared AVs will reduce overall car ownership and also parking requirements. The behavioural impacts for shared AVs are uncertain - it has been assumed that people make choices based on the marginal cost of travel. The higher marginal costs felt by users of a shared AV service lead to lower car demand; more public and active transport; and less congestion.

Modeling Autonomous Vehicles - Challenges and Results

Since the TRB Conference, TransPosition has done some more work on the modelling of shared AVs. Previously, only single-occupant shared AVs were considered however this paper now includes some preliminary modelling results for multi-occupant shared AVs as well. It is thought that multi-occupant shared AVs could significantly increase the efficiency of our networks. Multi-occupant shared AVs allow for more car travel than the single-occupant shared AVs due to their lower dollar cost. The growth in demand is limited to some degree by the higher perceived value of time spent in the company of strangers and the slight operational losses associated with picking up and dropping off the other passengers. Nonetheless, the higher vehicle occupancy allows greater mobility without any significant increase in system cost and safety outcomes. This paper also addresses potential safety implications and comments on mobility-as-a-service (MaaS). This paper was presented at the 2016 AITPM National Conference.

Driving alone versus riding together - How shared autonomous vehicles can change the way we drive