Road to the future

By just the year 2036, 1.4 million people are expected to be in the Melbourne CBD on an average weekday. This rapid urbanisation of cities is attributing to an increase in pollution and traffic congestion and a poor quality of life. This congestion comes at a cost to the Australian economy. In 2015, the congestion cost was $16.5 billion, and this is expected to increase to $37 billion by 2030.

Autonomous vehicles (AVs) have the potential to grow our cities beyond their current limitations and to keep up with growing cities whilst reducing the environmental impact. The carrying capacity of road infrastructure can be increased by up to 50% just through autonomous vehicle platooning.

Autonomous vehicle technology and its enabled mobility services are evolving at a more rapid pace than the understanding of the infrastructure required for them to be efficiently and safely implemented. As per figure 1 to the right, the ‘Society of Automotive Engineering’ established the 6 levels of automation. Automation starts at level 0, where vehicles require the full attention of drivers to level 5 vehicles which do not require any driver attention and monitoring.

Figure 1. Levels of Automation

This article focuses on the period 2029-2039, where level 4 AVs with private ownership will be as prevalent as Tesla’s in 2022. Research by the Australian Driverless Vehicle Initiative found that nearly 70% of commuters would prefer to use AVs as their mode of transportation, particularly when travelling during peak hour. This level of demand highlights the need for infrastructure preparation to ensure the safe and efficient operation of AVs.

Given the spatial constraints governed by the existing road network, existing road corridors must be repurposed to incorporate AVs. Figure 2 below shows an overview of the type of infrastructure required to integrate AVs into the transport network.

Figure 2. Original Image - Infrastruture Victoria

A brief summary of AV supportive infrastructure shown in figure 2 are shown below:

1. Multi-storey Carpark access for level 4 AVs to drive off and park themselves. Carparks can incorporate charging and maintenance services for AVs.

2. Extended bicycle lanes and footpaths to allow for more space for multimodal or active transport users so they too can navigate the transport network safely while AVs are on the road.

3. Traffic lights, ITS and digital infrastructure will need to be upgraded to communicate to AVs, guiding them through our roads efficiently and safely.

4. Park-and-ride will become dominant in large cities where residents need public transport to travel to their workplaces situated often in the CBD. With AVs having the ability to operate without driver supervision; commuters can be dropped off wherever they prefer whilst AVs can go park or serve another commuter. Thus kerbside spaces can be regulated and used for AV pick-up/drop-off and transit stops during rush hour, commercial use in the evening, and freight use overnight. Similarly, Autonomous shuttle buses can operate between park-and-ride stations to transfer commuters to park and access their hub easily. These mobility hubs can be expanded into existing kerbsides.

5. AVs have an increased lateral control and therefore require smaller lane widths. AV exclusive lanes facilitate platooning and thus increase the carrying capacity of the road. Finally, urbanisation is rapidly occurring throughout the world with growing demand and pressure on the current transport system resulting in congestions and an unsustainable road network. To allow a seamless integration of AVs from a system of conventional or simply connected vehicles, there is a need to review and develop policies and guidelines for road infrastructure.

It is essential that relevant infrastructure as discussed above is implemented at the key nodes or joints of the city. Engineers, transport planners, councils all need to come together to determine AV implementation framework that guides and inspires us to take our cities to the next level. Effective AV infrastructure implementation will combat the rapid urbanisation of large cities, reduce congestion, and improve quality of life to support our future and next level aspirations.

A feature by Riddhi Kalra, Civil Engineer - Aurecon & Hesavar Manivasakan, Civil Engineer - SMEC