What comes after the Self-Driving Car?

Jonny CabThe dream of the self-driving car now seems within reach.  But the implications of this new development go beyond simply being able to take your eyes off the road.  Once you have a car that can drive itself, what will that mean?

  • There will be no need to park your car.  The car can drop you off where you want to go, and then park itself, perhaps at some distance.  When you need the car back, you can summon it using a smart phone.
  • When you need to rent a car, there’s no need to go to a rental facility.  You can rent the car using your smart phone, and the car will come to you.
  • With that capability, there’s no need to rent a car by the day or longer.  You can rent it for a single trip.  When you’re done with it, it becomes available for use by someone else.  What this ultimately means is that there’s no longer a need to own a car.  And what that means is that a city doesn’t need one car for each person, but only enough cars for all the people who will be traveling at peak times.  Sharing cars means lower costs, and fewer parking spaces, which lowers costs even further.
  • The problem of getting people to and from mass transit stations, known as the last mile problem, is solved.  This will increase the utilization of public transit, and eliminate the need for park-n-ride lots, which will free up valuable land surrounding transit stations for high value development.
  • Lower capacity public transit, such as busses, will likely fall into disuse as people opt for the new on-demand, point-to-point service with no routes, schedules, or transfers.  As cities retire under-utilized, money-losing bus routes, a major drain on public resources will be eliminated.
  • Manually-driven taxis will also likely be replaced by the less expensive autonomous taxis.  And people will appreciate that fact that computers don’t ask for tips.
  • What little parking is needed can be much more compact because you don’t need access to each individual car, but only to the first car in the queue.  You also don’t need to allow space between cars for people to get in and out.
  • Vehicles can communicate by digital radio with each other, and with central control computers to better manage traffic.

All these things can be accomplished without any changes to our infrastructure of roads, traffic signs, traffic signals, etc.  But our vehicles and our infrastructure have been designed together to work well with each other.  One of the biggest challenges of the self-driving car is getting it to work in an environment that wasn’t designed for it.  That might be worth the effort if our roads didn’t have any other problems, but they do.  At intersections, traffic can flow in only one direction at a time.  That slows traffic, wastes energy, and transforms the street from a thoroughfare into a storage facility for vehicles waiting for their chance to go.  When the number of cars on the road exceeds the road’s storage capacity, the result is gridlock.  And roads take up far too much space.  They’re expensive to build, and expensive to maintain.  They’re hostile to pedestrians, bicycles, children, and animals.  They create heat islands, and polluted runoff.

But what if we developed an improved infrastructure in concert with improved vehicles.  What would that look like?

  • More precise steering will allow for narrower automatic-car-only lanes.  But there will need to be a way to keep larger, or manually-driven vehicles out, without blocking other traffic.  The easiest way to do that is to elevate the automatic roadway.  This can be affordable because the narrower lanes are lighter and cheaper than a conventional elevated roadway that must be robust enough to accommodate heavy trucks.  These dedicated lanes have no need for street lights, traffic lights, or traffic signs, and the vehicles wouldn’t need head lights, tail lights, brake lights, turn signals, rear view mirrors, or windshield wipers.  (You may have any of these, but you don’t need them.)
  • On a surface street there’s nothing but a painted white line to separate lanes.  For greater safety and reliability, a dedicated roadway can be designed in such a way that it constantly keeps vehicles perfectly centered in their lane.  This kind of road, called a “guideway”, can pass right over pedestrians, ground-level traffic, or other guideways  so vehicles don’t need to stop at intersections.  When they need to turn, the traffic control system can safely merge vehicles by making minor speed adjustments ahead of time so there is an opening in traffic just when and where it’s needed.  When autonomous vehicles arrive at their destination, they can pull off the main guideway onto a siding where they can stop without slowing traffic on the main line.  That means no stop signs, no traffic lights, and no waiting for someone to pull our of the driveway in front of you.  In fact, there’s no need to come to a stop until you reach your destination.  And the automatic controls enable closer headways, which increases capacity.  By keeping traffic moving, a single-lane guideway can carry a surprising amount of traffic.  Energy is also saved since most of the power is used to accelerate vehicles up to speed.
  • Electricity can be supplied to the vehicles through the guideway, so there’s no need to lug around heavy fuel tanks or batteries, no need to stop to refuel or recharge, no need for imported fuel, and no spent batteries to dispose of.
  • Roads, freeways, parking, and other automobile infrastructure use up huge amounts of land – estimates are about 50% in modern cities.  So far, efforts to increase metropolitan density have mostly focused on making buildings taller and closer together.  But the easiest space savings are to be had in transportation.  By combining the network configuration of surface streets with the non-stop throughput of a freeway, even a single-lane one-way guideway has enough capacity for most areas.  This compact guideway can be supported by widely spaced pillars, so there’s very little ground-level impact, leaving more room for green space, infill development, or any combination of the two.

This is what we are evolving toward: automatic electric vehicles that run non-stop on narrow overhead guideways, without batteries.  But here’s the really amazing thing – this ultimate system, called an Automated Transit Network (ATN), is far easier to build than a robocar.  It’s also safer and cleaner.  In fact, it has already been developed, tested, and put into passenger service in several countries.  The first system, built in the 1970s at West Virginia University, continues to operate today with an impressive record or reliability and safety.

The speed with which car companies have jumped on the autonomous car bandwagon has created a great deal of excitement, and a sense of forward momentum.  But there are a number of economic, technical, legal, and regulatory hurtles yet to overcome.  Many of the problems with our ground transportation system are due to the fact that it is on the ground.  Once we have self-driving cars, people will begin to see that guideways provide advantages that roadways can never match.  Since we can see this coming, we may as well start planning for it now.

The gradual introduction of automated vehicles may seem seductively easy.  But during the transitional period when manual and automatic vehicles must share the road, all vehicles will need to be crash-worthy, which will limit the opportunities to reduce vehicle cost, weight, size, and energy use.  As time goes on people will begin to demand that manual vehicles be banned from the roads as a safety hazard.  Someday the idea of allowing large motorized vehicles near where people are walking will be as unthinkable as leaving a high-voltage electrical line lying on the sidewalk.

Many people presume that change can only happen incrementally.  But history tells a different story.  Time and again, we’ve seen that when a new kind of infrastructure gains public acceptance, it goes from curiosity to ubiquity in just a few short years.  We’ve seen this with railroads, the interstate highway system, electricity, telephones, radio, television, cell-phones, and the Internet, to name just a few.  The first transatlantic flights by jet began in 1958, and within ten years the ocean liner industry had all but vanished.  The seaports did not evolve into airports, and the ocean liners certainly did not evolve into Boeing 707s.

Many municipalities throughout the world have expressed an interest in ATNs, but also an unwillingness to be the first to implement one on a public right-of-way.  This reluctance has led many people to conclude that innovation in infrastructure will not be possible anytime soon.  As a result, research has largely been confined to vehicles that can operate on existing roads.  This pattern is likely to change suddenly with the first successful urban ATN implementation.  Once there is an established “roadmap” for deployment, cities everywhere will find the confidence they need to move ahead quickly.  This is what we call the “Sputnik Effect” – governments can move remarkably quickly once external events give rise to the fear of being left behind.

Incremental change is easier for people to accept, but in this case we have the opportunity to bypass many challenges, and start enjoying the benefits of better transportation now.  Why invent new technology when we already have something better?  By going straight to full automation, there’s no need to teach millions of drivers how to switch between manual and automatic operation.  With powered guideways, vehicles can be much lighter, and the problem of building millions of charging stations goes away.  We can also sidestep the legal liability issues raised by the autonomous car.  Consider that collisions involving an autonomous vehicle will be big news, even when a human driver is at fault.  All that bad press (and the associated lawsuits) can be avoided by keeping the autonomous vehicles on a dedicated guideway.  In that controlled environment, the self-driving car will be faster and safer than a conventional car.

Many people presume that the transportation systems of the future must continue to rely on the infrastructure of the past.  Finding ways to make better use of our existing roadways is a worthy goal.  But as the need arises to replace dilapidated infrastructure, or to build new developments, we should take a long, hard look at all the options, even innovative ones.  No one is suggesting that we should discard what is already bought and paid for.  But the issue today is how we can best spend our limited transportation dollars going forward.

By running the vehicles on a dedicated, powered, smart guideway, the autonomous car is transformed from a long-term research project into a practical reality that can be built economically today.  And that’s a good thing, because we have a pressing need for it right now.  Traffic congestion and traffic fatalities, air pollution and global warming, dependence on imported oil and the automobile’s insatiable appetite for more and more land, all cry out for a solution today.  Automated cars are fine as far as they go.  But what we need today is not just a better car, but a better transportation system.

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