Future with driverless cars 6: Zoning, Traffic volume and Externalities


This is part six of a series on changes that driverless cars may bring. I expose some of the ideas I have, mostly quite practical things. We moved project troglodyte to it’s own website, so the more patent centric recap of the Google driverless car patents can be found from there.

Below I assume that the problem has been solved completely. Driverless cars can access any part of the road network, function even when there are people darting around and can handle any weather including lots of snow and very slippery conditions. Accident levels are same or lower than currently and people are not scared to use autonomous cars.

See also: Rental vs. taxi, Mass transportation, Pirvate cars, Cargo, Parking and driving empty, Zoning Traffic volume and Externalities

In smaller scale considerable flexibility will be created when parking can be some distance away from destinations. In densely populated areas parking facilities can be concentrated to avoid parking on the streets and the most valuable lots can be used more efficiently. In areas where snow cover makes street maintenance difficult cars can be either automatically moved to allow for removal of the snow or parking on the streets can be prohibited.

Removing parking from some areas makes it possible to create very densely built environments where walking is an attractive alternative for moving from one place to another. Denser areas also strongly support public transportation as the total trip time will be low due to short walking distances.

On a slightly larger scale putting commercial, industrial and residential districts close together would enable efficient sharing of vehicles as the same vehicle could transport several persons during one rush hour because the time driven empty would be short. In case of a city center/suburbia structure, serial sharing would also be possible if the rush hour peak is flat enough, but that would increase the total distance driven due to the long trip back to suburbia to pick up the next person.

In areas where the rush hour traffic is mostly one way and the road has several lanes to both directions using more lanes to the direction that has more traffic would increase capacity with relatively minimal investment to infrastructure. This is already possible with human drivers and even in use, though quite rarely. Using automated cars would make it much more flexible. Depending on how this is implemented it might be  necessary to forbid human driven cars from at least some lanes.

Automated cars can take kids to school. This would make it easier for people to live in very sparsely populated areas as parents would not need to drive their kids to school. Several kids could naturally use the same car when they know each other. As a downside parents might put children to schools that are quite far from their home. While this might have a leveling effect on house prices it would make the kids spend a lot of time travelling. The effect on housing prices is due to the fact that parents are willing to move to areas where good schools are available. This is apparently an important factor creating price divergence between areas.

Overall traffic volume would likely increase as driving would be easier, autonomous vehicles would be able to drive by themselves and new groups of people could use private cars. On the other hand relative price competitiveness of public transportation especially busses would likely increase.

People seem to be fairly bad at estimating how expensive driving is, this is particularly true before they make decisions that affect their driving needs for years to come. So costs of car maintenance, operation and time spent in traffic jams have a delayed effect on behavior. Because of the holding pattern parking problem an environment with many automated cars needs some sort of congestion charge system that is dependent on the distance driven and on the current need of that part of the road network. If electric cars become popular and the price of solar panels keeps plummeting, fuel cost might be close to zero in some cases. This would amplify the unnecessary use of road problem if no separate charge for road use exists.  Knowing that every kilometer is charged might have an effect on how willing people are to use a private car and lead to a lowering of the traffic volume.

The most common externalities of traffic that are affected by automating driving are land use for roads, adding to climate change and noise.

If the traffic volume does not increase significantly then the growth in capacity per road area brought by automation could lower the need for land under roads. It could also be possible to use smaller intersections especially on faster roads as traffic on adjacent lanes could have larger speed differences.

A major contributor for traffic land use change could come from the relocation of parking space to less valuable areas. Increases in popularity of public transportation will likely lead to higher throughput for the road network.

Noise is dependent on the number of cars but also strongly on their speed. Automated cars will follow speed limits so lower speeds can be used in areas where the harm from noise is large. Automated traffic can also lead to less accelerations which produce more noise than steady speed. Automated cars travelling empty can drive very slowly to reduce energy consumption.

Acknowledgment:  Thanks to Laston Kirkland for thoughtful evaluation of these ideas.