Intelligent Transport Systems (ITS)

How will autonomous cars change traffic flow?

haydn.thompson Friday September 1, 2017

In a future world with autonomous traffic it needs to be remembered, that not all vehicles will be autonomous. There will be a mix of autonomous and human driven vehicles and also pedestrians. Humans are naturally unpredictable and this lack of predictability presents huge challenges to autonomous systems and is likely to be the main cause of accidents in the future. From a social standpoint drivers and pedestrians may well need to adapt the way they drive and interact with roads and traffic in order not to disrupt the autonomous flow of vehicles. A question is how well will drivers integrate with a traffic flow of autonomous cars? This could be daunting for drivers who are not used to interacting with autonomous vehicles and could well be frustrating to some drivers who wish to have the freedom to get from A to B using their own driving style or via their own preferred route. It should be noted that autonomous cars will always follow the law whereas humans may elect to break the law by speeding, jumping a light or even ignoring road directions. It is a fact of life that autonomous cars must be able to react appropriately to bad human driving.
Humans may also not do what an autonomous car may anticipate. A classic problem is a driver deciding to stop unexpectedly in the middle of the road either intentionally or due to a sudden break down. Systems must be designed with high safety requirements and human-friendly behaviour which accounts for such unpredictable actions. These needs should be addressed both at a low level (e.g. guaranteed reliable sensors for people, car and obstacle detection), at a systems level (e.g. new algorithms for people tracking and new human-robot interfaces) and finally through systems for validation and certification.
So what will be the impact on traffic flow and society as a whole as we get more autonomous cars on the road? A key consequence will be control of traffic flow. This will naturally reduce congestion and should produce more predictable journey times. Drivers in future should be happier because they are not stuck in traffic, they should be less frustrated and stressed and should also benefit financially because they are driving more efficiently. More consistent traffic flow will lead to more predictable journey times with better on-time arrival for work and meetings.
However, what concerns me is what happens if I get up late and need to get to work quickly? I’m afraid if traffic flow becomes regulated there will be no option to get up late in future as it will not be possible to drive faster. So in future it looks like we will need to always ensure that we set off on time – or work from home of course…