The end of public transit
I've been writing a lot about self-driving cars which have automatic accident avoidance and how they will change our cities. I was recently talking again with Robin Chase, whose new company, goloco attempts to set people up for ad-hoc carpools and got into the issues again. She believes we should use more transit in cities and there's a lot of merit to that case.
However, in the wealthy USA, we don't, outside of New York City. We love our cars, and we can afford their much higher cost, so they still dominate, and even in New York many people of means rely strictly on taxis and car services.
Transit is, at first glance, more energy efficient. When it shares right of way with cars it reduces congestion. Private right of way transit also reduces congestion but only when you don't consider the cost of the private right-of-way, where the balance is harder to decide. (The land only has a many-person vehicle on it a small fraction of the time compared to 1-3 passenger vehicles almost all the time on ordinary roads.)
However, my new realization is that transit may not be as energy efficient as we hope. During rush hour, packed transit vehicles are very efficient, especially if they have regenerative braking. But outside those hours it can be quite wasteful to have a large bus or train with minimal ridership. However, in order to give transit users flexibility, good service outside of rush-hour is important. If we create self-driving, accident-avoiding cars, the safety rules of vehicle design change. In particular, we can make vehicles a great deal lighter. Once you feel confident that the accident rate is extremely low, the vehicle can look more like an electric tricycle or quadcycle with a fiberglass shell than a steel car. This is particularly true of the "city car" which need not be able to go more than about 40 mph, nor travel more than 10 miles in a trip. Because these vehicles will be able to autonomously seek out charging or battery exchange stations while not being used, they can make do with much less battery weight as well.
Indeed, the more people are willing to think of the vehicles as taxis, and thus switch vehicles whenever that makes sense, each vehicle can be tuned to the trip that will be taken in it. You might own a vehicle with a 10 mile range, and just swap off to a different vehicle for longer trips, or trips needing cargo space, as needed. (In other posts I've outlined the concept of a standardized locker for your "stuff" which is lockable and easily moved to another vehicle, perhaps automatically.)
One could even imagine that you start a trip in your own 10 mile vehicle, but as the battery gets low, it pulls over into a small parking area where you walk into a second similar vehicle for the next 10 miles. Your vehicle uses its remaining charge to go find a full charge, and waits for you or rents itself out. You would not want to do this every day but it would be fine for those odd longer trips.
This ability to use exactly the right vehicle for the trip will make these 1-2 passenger city cars even more energy efficient than transit, certainly that transit during light occupancy periods. And of course, superior in every other way -- no waiting, direct routing, privacy, peace and quiet, not stopping enroute etc. Even if the transit lines remain the most efficient during rush hour, it will make sense for them to shut down outside those hours, and even ideally cede their dedicated right-of-ways to vehicles able to use them.
Computerized trip routing can also create highly efficient jitney cars that may even win in rush hour. A jitney car might consist or 4 to 8 personal "pods" with their own privacy and workspace. A trip, calculated by the computer, might take you one mile in a single-passenger vehicle to an instant transfer where you step into the pod for the shared part of the route. Later you would step out to transfer to another single passenger vehicle. Aside from the minor inconvenience of the quick transfers, and brief stops for other passengers to transfer, it would provide much of the efficiency of transit with a vastly superior experience, including a private, internet-connected workspace pre-assigned to you. Of course, with even more efficiency, traditional transit vehicles could be assigned to the busiest common routes.
One final reason transit is efficient is that one vehicle deals with less wind resistance than individual cars do. Wind resistance is the greatest loss of energy in cars at higher speeds, which is why trains do so well. However, it is possible for self-driving cars to coordinate with one another so they can "draft" one another and get back some of these gains.
I don't see people choosing transit very often with these alternatives available, and so I predict the possible death of public transit in 10-15 years time. Why do people use transit today, other than a feel-good desire to be more efficient?
- It's cheaper than a car if you don't own one, but for those who already feel they must own one, they look at only incremental costs (gas and parking) and often don't find this a win. Cheap automatic cars will be a bigger win.
- At rush hour, dedicated right-of-way transit can be faster if it's going on your route. Automatic cars will not suffer congestion.
- Finding parking is time-consuming and expensive. Automatic cars will self-park or earn money when not used.
- Though transit often is slower, you can read or work, which you can't do while driving. You can do this in a self-driving car.
- It's generally safer, but accident-avoiding cars will be equally safe.
The self-driving cars eliminate almost all the advantages transit is able to have. In part they do this by taking advantage of the existing road infrastructure we've already built to make them cost-competitive. But it's hard to see transit winning, even though it also can gain from technology improvements.
Thu, 2007-05-03 08:28
Public Transit inefficient after-hours
While I agree that running fixed route, fixed scheduled service is an inefficient means to run transit services after-hours, with a certain amount of flexibility, one can achieve the same or better level of service levels with fewer resources.
A case in point, Oakville Transit, which operates transit services for the town of Oakville, Ontario - 30 minutes west of Toronto - uses a number of small airport-style shuttles for off-hours service. Their is no fixed schedule, nor are there any fixed routes. All routes are created on-the-fly by the drivers.
One need call only 45 minutes in advance of when they need the bus. The dispatcher will call you back with the exact time to be at the bus-stop.
The result is a very efficient system with utilization of available seats near 100%. There is less of a wait than with the fixed-route/fixed-schedule approach.
A city of 150,000 can be served by four mini-buses this way.
As a result of this service, I have been able to give up my use of a car, which I think is an excellent result.
Thu, 2007-05-03 14:15
This is a good start, but 45 minutes is obviously too long a wait for certain applications, and just fine for others. There are many times when you decide you're going to leave at pretty much exactly the time you leave.
One could build a system to do it better, but there are inherent limits since you obviously want multiple people on the shuttles. A jitney service may make more sense though might not be quite as efficient.
Of course, in some cities, you can wait 45 minutes for a cab. Due to bizarre regulations, the taxi companies in San Francisco can not guarantee you will get a cab. They are required to treat the drivers as independent contractors and though they might call a driver to come to your house, the driver is allowed to bug off and you can't do anything about it, as you have no contract with anybody until you get into the cab.
Oakville of course is very suburban. I know, I grew up in Clarkson.
Sat, 2009-10-03 22:21
The end of public transit
Two years after I wrote that comment, Oakville has switched to primarily a fixed-route grid system. C'est la vie. My wife and I now use electric bikes for anything local.
Found your site again in the top three hits after searching "round-the-world" while looking for a RTW plane ticket for my wife and I. I noted you have an entry about robo-cars - interesting stuff, and I would like to read more of your thoughts on the future of transportation.
Sadly, I live in Ontario, which is one of the least progressive jurisdictions w.r.t. electric vehicles. ZENN has their head office here, but cannot sell their cars here. Government never ceases to cause me wonder.
How is the e-vehicle situation in S.F.? E-bikes?
Re: Your comment on growing up in Clarkson - I remember your name well, though you may not remember me. I ran "The Void BBS" off a C64 in Scarborough back in the early-to-mid '80s.
I enjoy reading your blog.
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