Self-Driving Cars: A Story About Our (Possible) Future

"The best way to predict the future is to invent it."  

-Alan Kay


For awhile, I've been intrigued by the possibility of self-driving cars and the effect they could have on how we live.  I have no way of knowing when the technology will be sufficient for self-driving cars, but people far smarter than me are predicting that they will be technologically possible within five years. (Elon Musk says the same timeline.)  Although they may never come to be, or society may reject them, I think any future planning that doesn't consider the strong possibility of self-driving cars and their revolutionary potential (and potential for harm) risks being overrun or overlooked.  If done right, we have a chance to change our cities for the better.

First, for the skeptics:  it's easy to dismiss this as outside the realm of technological possibility.  I think this is a result of thinking linearly when technology moves exponentially.  No one can explain this better than this Wait but Why post.  Go read just the first section of that and then come back.  For those that want to skip ahead, this is what exponential growth looks like:

OK, any more convinced this is at least possible in the next few years?  Then let's look at how these self-driving cars might change our cities by looking at the day-to-day life of a local citizen of San Diego.  Not saying this is necessarily probable, but only a possible best-case scenario.


Sam lives in Poway with her husband and two kids.  She works downtown.   She wished she could live downtown or in trendy North Park, but it costs way too much and she doesn't feel safe having her kids play in the street. Despite the commute, life is calmer and easier in the suburbs.  For her commute, she just got a brand new Honda Civic that costs $150 a month to lease.  The Civic gets really good gas mileage at 39mpg, but to drive the 22 miles to work, it still costs about $3.38 a day in gas a three dollars a gallon.  That adds up to about $70 dollars a month for gas, plus another $60 for insurance.  She also has to pay $150 each month for her parking spot downtown.  Altogether, she is spending about $450 a month to commute to work, and that's ignoring registration, oil changes, and other assorted costs.  Spread over 20 days of commuting, that's $22.50 a day. 


Showing her prescience, Mayor Capretz visited the professors at the UCSD/SDSU Technology Institute in Mission Valley in 2017 to ask about how they see the future unfolding.  They tell her that self-driving cars are coming soon and San Diego should start planning for them.  The Mayor assembles a task force to answer the question: assuming these self-driving cars are coming, what can we do to harness the good and block the bad?

On the task force's recommendation, the Mayor negotiates an unprecedented joint agreement:  beginning July 1, 2020, the city will offer a carrot to ensure it is on the forefront of this new technology: one lane on all streets downtown, on major arterials, and on each freeway will be devoted to the exclusive use of autonomous vehicles.  In exchange, each mile driven by a self-driving car for rent will be taxed at 50 percent.  All of this tax revenue is restricted to revamping the city in light of the potential changes from self-driving cars.  After 2025, each car purchased for personal use will be taxed at an extra 10%.  These measures easily pass because (1) no one owns one of these cars yet and don't see themselves being affected and (2) the conservative skeptics never believe these cars will materialize anyways.  She also passes a new ordinance requiring that any removal of on-street parking must be given to protected bike lanes before any other use.

Shortly after her announcement, the tech rumor sites report that Apple, Uber, Tesla, Google, and Ford have started to secretly buy up huge warehouses around the periphery of the city.  By laying out the biggest welcome mat of any city to the potential for self-driving cars, the companies have responded.


It finally becomes official:  Apple just announced their new AppleCarShare (ACS) system and Sam is intrigued.  The cars drive themselves, she can schedule a pick-up on her iPhone for any time and the car will be at her door, ready to whisk her to work.   After dropping her off, it whisks off to pick someone else up. The cost?  Not much.

Let's say the first AppleCar is a lot like a fancy 2015 Tesla, which costs less than 5 cents a mile to operate and about $900 a month to lease.  That 900 bucks a month is a lot for one driver, but Sam would be "sharing" the AppleCar with other people.  Rather than sitting in a parking garage all day while Sam is at work and in her driveway all night while she sleeps, the AppleCar is driving around picking people up and dropping them off when she isn't inside of one.  One study found that sharing these types of cars could equate to one car handling the load of ten current cars.  So if Sam can "share" the lease for AppleCar with ten other people, the cost comes down to $90 dollars a month per person.  That's just $4.50 a workday.  Even assuming that Apple includes an over-100 percent markup on operating expenses to 10 cents/mile, that means Sam would be paying in the ballpark of $6.70 per day to use the AppleCar, versus the $22.50 per day she was spending in 2015.

Even if the numbers are off and the ACS costs twice as much, Sam is still saving a lot of money. Likewise, the city tax hurts a little, but the price is still less than owning and the convenience cannot be overstated.  The exclusive use lanes allow ACS to fly around the city, bypassing most traffic.  Also, no more hunting for parking spots, no more paying for a parking garage.  No more oil changes, gas station stops, or haggling with car salesmen.  Not to mention that she can read a book or get some work done on the commute, and doesn't have to feel bad about having that second beer at happy hour before driving home (and taking one for the road).  Not to mention, the all-electric fleet is super green.  There's no doubt, Sam is signing up for the ACS.  Her husband, however, is not giving up his truck.  He needs it for camping trips to the mountains and for hauling lumber from the hardware store.


Despite the foresight to begin planning, the City wasn't quite ready for how rapidly residents adopted ACS.  Once Uber and Google got into the business, prices dropped even more.  Other than a few businesses that require all-day driving, there is hardly anyone that can make a case on the basis of economics or convenience for owning a car.  When human-driven cars offer no benefit for over 90 percent of the drivers, they disappear more quickly than anyone could have imagined.  Sure, there are still some people that drive their own cars, but they are vastly in the minority and people are starting to get tired of giving them so much space to park their cars.

Nearly all of the parking lots and garages downtown have gone out of business after service dried up.  People like Sam used to park in a garage, but now the ACS just drops them off in front of work and heads off to pick up someone else.  Before ACS, over a quarter of the land area downtown was devoted to parking lots.  Just like the garages, very few cars park on the street any more.  Apple bought one parking garage for charging and storage, but otherwise the cars are constantly on the move.  With most on-street parking spots sitting vacant, groups like the Hillcrest Business Association start pressuring the city to come up with a better use for the land.

The downtown condo and office buildings are also trying to figure out what to do with all of their extra parking space.  Facing immense pressure, the City Council agrees to drop all parking minimums in buildings.  Many buildings start to convert the former parking garages into additional residential units, causing a glut of new condos and apartments.  With the huge new supply, prices start to fall.  

In North Park and Uptown, almost every house has converted their garages to accessory units, quickly doubling the density of the neighborhoods.  Some of the residential streets that are over 50 feet wide serve no purpose any more: the self-driving cars only need 16 feet to drop people off.  A few blocks petition the city to allow for new zoning of small units in the excess street right-of-way, creating even more units and driving prices down further.

One day, Sam is at work and wants to meet her friends for a drink at Waypoint Public in North Park.  She has a couple of options.  She can take an MTS bus to North Park, which will cost $5.00 roundtrip and will take about 30 minutes.  Or she could hail an ACS, pay 50 cents total, and be there in ten minutes.  It's a no-brainer: she pulls out her phone and schedules an ACS pickup.  As a bonus, she gets someone in her office to come along; they split the cost to make it only 25 cents each.  If they had taken the bus, they wouldn't have gotten a discount.  More and more people are making the same decision: MTS ridership starts to plummet.

Meanwhile, Sam's husband finally sells his truck.  Home Depot now has its own fleet of self-driving trucks.  They are so cheap to operate that they offer free delivery of everything.  Why drive and load your own truck when Home Depot will do it for you?  Similarly, Amazon's self-driving fleet starts making two-hour free delivery a reality.  Many big-box stores in the suburbs can't compete and go out of business.  When they go camping the next weekend, they rent a specialized camper self-driving car: it's costs a lot more than a commuter ACS, but it is still a lot cheaper than owning a truck to use a few weekends every year.


Now that no one parks on the street and the ACS vehicles travel much more closely, the City has completed their redesign of the streets.  They narrow all lanes to 8 feet wide and end all on-street parking, other than a few ACS "valet" spots for pickups and dropoffs.  There is a little more traffic now that cars are so cheap to rent, but the self-drivers can travel within inches of each other on all sides, greatly increasing the capacity of each lane.  The city adds bike lanes and wider sidewalks nearly everywhere.

These changes have all been paid for by the city's tax on self-driving cars.  With over 80 percent of the 15 billion vehicle miles driven being done by the self-driving cars, San Diego is collecting over 600 million dollars a year in new tax revenue by collecting only a nickel for each mile driven.  600 mil goes a long way when changing the city's design.  Other cities weren't so smart and don't have the funds to revamp their streets.  

In a combination of this new revenue and a huge drop in costs now that no driver is needed and every municipal building is covered in highly-efficient solar panels, San Diego starts offering its bus service for free.  The smaller busses operate at the same speed as cars and quickly become very popular.  Even though ACS is cheap, it's hard to beat free, especially when the busses always run exactly on time.  The adoption rate for the free busses opens up even more street real estate, allowing for bike lanes everywhere and even wider sidewalks and linear parks.  In a positive feedback loop, the safer amenities for active transportation, the falling real estate prices, and free public transportation drive up demand in the inner suburbs.  At times it seems that demand will drive up prices to pre-ACS levels, but then the roads are further narrowed, more garages and parking lots are converted to residential units, and prices remain stable and low.

It's been three years since a car killed a pedestrian or cyclist anywhere near downtown!  The self-driving downtown speed limit of 15mph imposed back in 2020 sure helps: even when a biker strays in front of a car, there is no fatality.  Now that nearly every car in San Diego is electric, the air quality is better than it's ever been since 1920.

Given all the new condo units and townhomes popping up on old parking lots, plus the safe streets and ease of walking, Sam decides to scrap the commute altogether and move downtown.  The old house in Poway seemed weird: they had a garage they used only for storage and they didn't want to spend the money to jackhammer out the driveway and were stuck with a huge expanse of concrete that never got used.  And although some of the big-box shopping centers had started to convert their new wastelands of parking lots into restaurants and townhouses, it became pretty clear that the suburbs were designed for cars and adaptation wasn't going to be easy.  Some progressive cities were almost starting over, redesigning their new downtowns to allow for much denser development now that they could eliminate most roads and all parking lots.  Despite the increase in density, many suburbanites found their towns to be more beautiful and welcoming now that the asphalt was largely gone.

But Sam and her family love living downtown.  Her kids play outside and didn't have to worry about getting hit by a car.  Given the new bike lanes and complete safety from auto collisions, they ride their bikes everywhere.  Cheap cars are great, but it's so much fun to ride a bike when you don't have to worry about getting hit.  Sam thought she might not see her mother as much anymore because of her blindness and the hassle of picking her up in Murrieta, but her mom had learned how to hail an ACS and get downtown all on her own.  Similarly, her 13-year-old son is an expert at calling an ACS to drive him from school to soccer practice out in Mission Valley.

Meanwhile, out in Poway, a few old-timers cling to their human-driven cars.  As the normal stream of pedestrian deaths and collisions continues, residents flee to the urban areas where they can be safe.


After the tax on car purchases took effect, only the exceptionally rich continue to own cars.  Some people that swore the City would have to pry their steering wheels from their cold, dead hands capitulated in the face of the amazing ease and low cost of the self-driving cars.  All the polls suggest that the measure to ban human-driven cars will pass in November.  Once San Diego hits 100% adoption, the self-driving cars will be freed from including seatbelts, airbags, roll cages, and other safety features.  When the weight and additional components are stripped away, mileage prices drop just as quickly as energy use.  Experts predict the last gas station in San Diego will close by 2030.


After years of increases in self-driving cars, their use is starting to wane for most trips.  Many people can now afford to live downtown and in the closer neighborhoods, and choose to do so, resulting in shorter commutes.  Also, the free buses made a big dent in car usage.  Finally, the huge increase in safety for walking and biking also lead many to choose active transportation over paying for a car.  With all of the extra money that used to be spent on transportation and housing, San Diego's restaurant, bar, and entertainment sector is booming, leading to a low unemployment rate.

Looking back, most San Diegans praise Mayor Capretz for assembling the task force back in 2017 to ensure a beneficial path forward.  Other cities scoffed at the idea of a self-driving car utopia and did no planning.  They are now left with insolvent public transit systems, vast wastelands of excess parking spaces, and outdated parking ordinances.  They try to impose similar taxes, but now that everyone has adopted self-driving cars, they are always defeated at the ballot box.  Eventually they will catch up in building bike lanes and pedestrian facilities, but it's hard to catch up with San Diego given its head start.  If only someone had done some planning...