The below discussion between TTM Group Director Simon Crank and Urban and Transportation Planner and Professor at University of Queensland, Neil Sipe responds to the recent experiments with driverless cars in Australia. The discussion has been republished here with permission from the authors.

Car manufacturers have been investing decades of research and billions of dollars into developing autonomous vehicles designed for everyday use. 

Tesla announced 100 million miles travelled on AutoPilot earlier in the year, while Uber and Google have been hard at work trialling their fully autonomous versions on the streets of Silicone Valley; meanwhile Singapore is trialling the world’s first fully autonomous bus.

At this pace, it seems we’ll be “driving” driverless cars sooner than many of us expected – for some, it may even be your next car.

According to leading traffic engineer, Simon Crank from TTM, these changes will bring about unprecedented transformation of our lives, and our road network and cities must be designed to accommodate this.

“Our current road network has the capacity to move 2,000 vehicles per hour per lane. The introduction of autonomous vehicles will allow up to six times this on high speed roads,” says Crank.

The most obvious benefit of driverless cars is road safety. According to the World Health Organisation, road accidents account for almost as many fatalities as lung cancer, diabetes and respiratory diseases. The Queensland Police have identified the Fatal Five, as the leading causes of such accidents: distraction and inattention, fatigue, drink and drug driving, speeding, and failure to wear a seatbelt; human error is the undeniable common factor. 

By removing the driver, we can eliminate the error.

However, Urban and Transportation Planner and Professor at UQ, Neil Sipe says there are much broader implications than safety. 

“Congestion, commuting and parking will become a breeze. Spaces previously dedicated to parking and extra lane width will be opened up and reused by the public. Road infrastructure will be designed for accident-free environments,” says Professor Sipe.

Driverless cars don’t require the same margin for error as humans. This will allow safer high-speed and bumper-to-bumper transit, creating a more efficient traffic flow. 

“We won’t need guardrails. We won’t even need acoustic barriers, as most cars will be electric. We’ll also be able to reduce the lane width, by up to a metre. In many cases, this will mean an additional lane is added within the existing road width; for others, it will mean the additional space is reallocated to bike lanes, footpaths, gardens and other usable public space,” says Crank.

“From a planning perspective time, technology and funding will determine whether the cars will continue to respond to the road conditions via sensors and cameras, or if they will communicate wirelessly with other cars and the entire road network infrastructure. Assuming the latter is the end goal, there will be less rapid breaking and acceleration, which makes for more efficient power or fuel consumption and a longer vehicle lifespan,” Crank added.

Convenience is another significant benefit of the autonomous influx. Whether it be the convenience of commuting or parking, the time spent during these often stressful and unavoidable periods can be devoted to something far more productive and enjoyable. 

“We will need to convert roadside parking to drop-off and collection zones, as people are dropped at their location before sending their vehicle to the nearest parking station. Many existing carparks will be adapted for commercial use, and those that remain will likely be redesign to become fully-automated vertical stackers. These will allow vehicles to arrive at a hole-in-the-wall before parking in an incredibly compact, high-density parking station,” says Crank. 

Whilst there are so many benefits, the jury is still out on a number of issues… 

Will there be fewer or more cars on our roads? 

The apparent ease of driving – that people don't have to do it – may attract more drivers. However, Simon Crank says there will always be a market for public transport. 

“Much of public transport will become automated, so we need to rethink how we provide these services. With no drivers, these will be more cost effective to run, so instead of running busses half empty during non-peak periods, we could operate a wider network of smaller capacity, on-demand services. The availability of fast, efficient and on-demand public transport options may negate the additional vehicle flow.” 

What does it mean for urban sprawl? 

Long distance commuting will be far easier to endure, as traffic flows at higher speed and greater capacity. Indeed, the biggest beneficiaries of this technology are likely to be those living in regional (and rural) areas, because they’re driving far greater distances. 

“Instead of sitting in traffic for over two hours each day getting to and from work, people can spend that time productively, preparing for their day – it may mean an extra hour of work, or of extra quality time with your family every day. There are significant economic and social benefits to avoiding congestion,” Sipe added.