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Comment by Tiktaalik | Hacker News Reader

The sorts of Driving behaviors you mention are not a significant cause of traffic congestion. Traffic congestion is caused by there being too many cars on the road with limited space for cars.

Anything that will increase the amount of cars will quickly dominate inefficient driving behaviors, and self driving cars will massively increase the amount of cars on the road, as it would drive down the cost of driving and enable many many people who currently can’t drive to get onto the road (eg. Disabled, elderly, unlicensed, children).

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> "Traffic congestion is caused by there being too many cars on the road with limited space for cars."

I mean in some sense this is always going to be true, and removing cars will always help alleviate traffic. But it's not true that driving behaviour is not a significant cause of traffic congestion: it's the cause in most cases. [1]

For an extreme illustration, there's a well-known phenomenon where adding extra lanes of traffic to a highway or freeway actually worsens traffic: the added bandwidth interacts in weird/subtle ways with driver behaviour. [2]

[1] https://www.vox.com/2014/11/24/7276027/traffic-jam

[2] https://www.wired.com/2014/06/wuwt-traffic-induced-demand/

Yes these are real phenomenons that exist, but focusing on this marginal issue is fiddling at the edges of the real core problem.

Roads are fixed in size, cars are very big and take up too much space.

Fundamentally baked into the design this is an inefficient way to move people around and there's no fix to be found working within a car oriented framework. The only solution is in removing cars from the road. This is why self driving cannot fix traffic as it will only add more cars.

Self driving buses, now that would be an improvement, but self driving cars no.

On top of this, a future where every car on the road is self driving also lends itself to a future where every car is in constant communication with the cars around it. A car 10 spaces ahead is slowing down? Your car already knows and is prepared to handle it with grace rather than slamming on brakes. Cars behaving in a predictable and communicable manner, as much as possible, alleviates traffic by a large factor.

This is obviously largely ruined by one single human driver acting unpredictably, so it's a very "all or nothing" resolution.

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