I’ve been thinking more about self driving cars, and realizing they could be even better than their hype.
If they serve as mobility services, like taxis, then people could save a great deal of money on car ownership, just treating a self driving car for when they need it. A further advantage of the rental model would be that people could order cars to their need. Who needs a minivan or SUV to go to work, when a Smart car would do? For these times when you need building materials or to carry a horde, order a self driving pickup truck or full size van for that trip.
One of the best things about self driving cars is that they are precise. We pave an area larger than Connecticut or the sake of avoiding sideswipe collisions. The reason the most common traffic lane width is twice the most common car width is that people’s steering is fallible. You can get into a lot of trouble in six feet at 65 MPH, but because the machines are standard and AASHTO “recommends” a 12 foot lane for all roads, newly built lanes are 12 feet wide even where the posted speed limit is 25 MPH. People driving in these places get the message though. Police can find a great revenue source, but at cost to public satisfaction. Self driving cars would do away with all that, allowing lane widths as low as 8 feet, or 10 feet where there is heavy truck traffic. We can use this space bonus for more lanes, or more places to live work and play. It would be like discovering a new state the size of Delaware. You are welcome.
If you wanted to reclaim even more land with self driving cars, reconsider the axle. If the majority of trips are single occupant, why is a four wheeled car even necessary all the time? Two wheeled, gyroscopically stable, and self driven motorcycles are possible, and could offer as much enclosed comfort as an airline seat. These could run in lanes only four or even three feet wide, as the human body is only 1.5 to 3 feet wide (ectomorphic to endomorphic). New Complete streets could consist of a sidewalk, bike lane, parking lane, 10 foot wide lane for family cars and freight, and one or two 4 foot lanes towards the center for single occupant vehicles. The severity of head on collisions would be much less between smaller vehicles, and the 36’ section of traffic way could hold six lanes of traffic in the same space as three lanes today. A walker could cross that in under 10 seconds, a significant improvement over the 20+ seconds it takes to cross a typical six lane highway with raised median.