To discuss transportation, we must agree on what the goals of a transport system are

Busy Argentine bus stop

People love mass transit. By this, I mean there are a lot of people who, either for historical or emotional reasons, love transit as a good in itself, rather than a means to various ends.

As The Onion put it so brilliantly, 98 Percent of U.S. Commuters Favor Public Transportation for Others. The satire is funny, but also true.

To really discuss the future of transportation (and in particular mass transit) in the face of a technological revolution in mobility, it is vital to look not at Transit, but the goals we have for it, or rather the general goals we have for all our transportation.

This is a foundational article, to be the basis for future articles on where transportation is going. It does not try to make too many points, but rather lays the ground rules. I welcome input on improvements to these goal lists.

Some of those goals are the goals of the traveller. Others are goals of the city or society. Sometimes those come into conflict.

The Traveller's Goals

  1. Short and predictable travel times, with minimal waiting
  2. Safety
  3. Flexible departure times
  4. Reliability and availability
  5. Low cost
  6. Pleasant travel: Comfortable, smooth, seated, peaceful, private, healthy, fun
  7. Ability to do things on the trip
  8. Specialized needs of some travellers:
    1. Access, regardless of disability
    2. For low mobility people, minimal walking
    3. For groups, good support of group travel desires
    4. Socialization (with other commuters)
    5. Exercise
    6. Expression
    7. Ability to carry goods
    8. Visibility for sightseeing
    9. Full RV function for road trippers
  9. More pleasant neighbourhood and streets for living/walking (including less pollution and noise on streets)
  10. Protection of civil rights (freedom, privacy, etc.) during travel
  11. Moral convictions about some of the social goals -- for example many will seek low emissions, safety for others etc. for altruistic reasons and the good feelings they generate

Or in concise form: Quick, predictable, reliable, available, safe, pleasant, cheap, easy, with parcels, non-destructive and ideally green.

Society's goals

  1. Serve the goals of the individual traveller
  2. Make optimal use of given infrastructure, and reduce costs of maintaining it or creating new infrastructure
  3. Meet the traveller's goals so they will use transport that meets society's goals (typically group transport.)
  4. Safety for others/all -- the traveller's goal of safety is somewhat more selfish
  5. Lower emissions per passenger
  6. Low public cost
  7. Enforce urban planning decisions (controversial)
  8. Reduce other negative externalities of travel, play nice with other modes
  9. Treat people equally
  10. Ensure equal transportation availability for lower income people, seniors, the disabled and minorities
  11. Future-proof

Or in concise form: High throughput, pleasing, popular, cheap, safe, green, equitable, accessible, future-proof and fitting city plans

You will note that some things like "reduce traffic congestion" are not listed here. That is a means as well -- reducing congestion helps shorten travel times and make them more predictable, and increases throughput and fairness. And of course "share vehicles" is quite explicitly not on this list, rather it is a means to some of these ends.

People and society also want goods to move. The goals are not identical, but fairly similar. They are usually subordinate to the goals for human transportation, though we generally want to give goods lower priority in any battle of the goals.

Details on the goals

With the list there, let me provide a few more details on the various entries. In finding our answers, it's immediately clear that there are trade-offs between these goals. There can be conflict between individuals and between individual and societal goals.

Short and predictable travel times, with minimal waiting

This is very high on the list, obviously even surpassing safety when you consider the reckless way many people drive. The desire for short travel times is extremely strong, and on some trips, the variation can almost be added to the travel time. For example, when going to an appointment that can't be missed, if the trip can take anywhere from 10 to 30 minutes, you must leave 30 minutes in advance. Waiting adds to travel time but it also hurts satisfaction. People would rather a 30 minute trip than a 20 minute trip with 10 minutes waiting, as that seems more wasteful.

In the counter direction, the fact that everybody carries an entertainment device with them has made waiting more palatable, and also helped provide information to reduce uncertainty in times.


As noted, this would go first if it weren't for the fact that people routinely compromise it for faster speeds, lower costs and other things. Another type of safety is personal safety from other riders and people on the street, felt most strongly by women or people who live in places where it is dangerous to walk.

Flexible departure times

One of private transport's greatest attractions is that it leaves precisely when you wish. Clearly trains that come every 10 minutes are vastly preferred to ones every hour. At the extreme, hourly frequency can be like adding an hour to the travel time.

In addition, this means service to everywhere, at all times of the day, to fully meet this goal. Ideal transportation departs precisely when you want to leave, at any time of day or year.

You can't fully decouple this from total trip time. To some extent, total trip time can be viewed as travel time plus average (or specific) departure wait, but for some the unpredictability can be a negative. For others, the waiting component is preferable to the travel component for getting stuff done.


Certain levels of low reliability are unacceptable. Car breakdowns, transit breakdowns, strikes, weather -- whatever the cause. Most travellers need an alternative method available (like Uber) even if expensive, in all but the most extreme situations. Short of that, poor reliability also adds unpredictability to the travel time.

Low cost

It is hard to place cost on a priority list. What's clear is that transport is important enough that the vast majority of Americans and Europeans accept the very high cost of car ownership -- around $7,000 or more per year -- to get what they want. Everybody wants low cost, but many will pay more for superior service.

Pleasant travel: Comfortable, smooth, seated, peaceful, private, healthy, fun

Almost nobody doesn't want these, and obviously they are a large part of the popularity of private transportation. Even so, public transit can range in experiences from overcrowded standing on packed buses with bad AC and bad suspension to reserved business class train seats with waiter service. Most transit lines, to increase capacity, abandon seating at rush hour but usually have it off peak. Some vehicles have toilets, which greatly increases comfort on longer trips.

There really are many goals here, some which compete with one another, such as fun vs. peaceful. However, to make the list more concise, I combine them into one.

Ability to do things on the trip

Previously, one of the big disadvantages of the car was you had to drive. This gives advantage to passenger services like Transit and taxis. The robocar alters this dynamic.

Specialized wants and needs

These are things wanted by many travellers, but not all

Access, in spite of disabilities

This is an individual goal, for those with the disability. Not all riders care directly about this but they may care for moral reasons.

For low mobility people, minimal walking

The amount of a trip that is walking can be seen two ways. Mostly people do just care about total trip time, and walking often increases that. On the other hand, many enjoy walking when it adds only modest trip time -- except if weather is bad. Those of limited mobility however may not be able to do a walk of any significant difference even on a nice day.

In addition, for certain people, things like stairs or inability to roll may make a transport method entirely unusable or very difficult.

For groups, attention to their wants

Some travel as families or groups. They desire to be together and socialize together, and wish privacy and safety for their group. They usually expect lower pricing per person.


A small number when discussing the transition from mass transit to private transportation, regret the loss of the group experience and social interactions on a regular commute. I believe this is a fairly small contingent, but it is real.

For some, exercise

Many will say it is good for them to be forced to walk more, that the availability of door to door transportation, while more pleasant and faster, hurts their health. While riders can elect to walk some of the route, people find it easier if they are "forced."

Carrying goods

People wish to carry goods, including large and heavy items, on some of their trips. They wish minimal walking, no stairs, space to put the goods, security for them and ease of placing them in and out of a vehicle.

People also like to have goods with them, such as stuff for their children, and have access to them on every trip.


Tourists and road trippers like to see the view

RV/Limo services

Some travel for the sake of travel, or want the full function of an RV, though usually more in rural settings


People like to express themselves as they travel, which gives them a desire for choice and to display their choice and wealth as they travel. While this is often seen as a petty want rather than a need, it is quite probable more is spent on this than is currently spent on all public transportation.

More pleasant spaces when walking (including less pollution and noise on streets)

This sits on the border of traveller desires and social ones. The travellers want the city to be a pleasant place to travel and live, particularly in the areas they will walk, so they don't want other people's transportation to hurt that. People would prefer to be able to freely cross streets as they please. This is sometimes seen as a societal goal, but there is no person who would not prefer pleasant streets, and so the social goal is mostly an aggregate of individual desires. (Though unlike other individual goals, this is a desire over what other people will do.) People also live on streets (and often try to live on cul-du-sacs) and relax, eat and recreate on or next to streets.


When I travel, I want to retain my freedom, my privacy and other civil rights.


There are things people want not so much for themselves, but to work to make the world as they wish it. As such they will care about pollution even if they won't breathe it and many other things. Many punt these decisions to the realm of public policy, but others alter their own actions based on them.

The Social Goals

Meet the traveller's goals as they are human goals

The primary goal of any transportation system is to give satisfactory transportation to the people. While other goals may alter how this is done, it should never be forgotten that this is the prime purpose, to be accountable to the people. Give the people what they want unless there is a compelling reason otherwise.

Optimal infrastructure use

The most compelling goal for mass transit is throughput. Getting more people through a given bit of infrastructure -- land, tunnel, road etc. This mostly matters at peak demand times. We want to get the most out of the roads and tunnels we have, and reduce the cost of anything new that has to be built. They are a shared resource that should be shared well.

Attract riders to systems which meet the social goals

In addition to the broad goal of giving the people what they want, if social goals are met by group transport, it is often forgotten that to do this it is essential to be good enough so that people choose it. Otherwise they abandon it for other forms, negating realization of the goals. This is related to the primary goal, but sets a specific sub-goal within it to attract the critical mass necessary.

Safety for others

Everybody is concerned about their own safety, but the government needs to protect public safety, particularly for people not even using the transportation system.

Lower emissions per passenger

Nobody wants pollution next to them, but society has an interest in reducing the emissions for each passenger. This is related to the energy used by each passenger, electric energy and liquid fuel energy can be quite different, even from place to place. In some places, electricity comes mostly from burning coal, the biggest killer of all the energy sources.

Low cost

Travellers want low cost for themselves, but society also wants to minimize expenditure of public money. Many government-run transport systems deliberately run at a significant loss to their farebox revenues. In addition, infrastructure building and maintenance has a cost, as do many externalities whose costs should ideally be factored in.

Enforce urban planning decisions

Sometimes transportation goals will be set aside to meet other goals designated more important. Transportation that the people want may be blocked or impeded to meet goals of an urban plan. Limiting transit stops encourages more dense transit-oriented-development, even though riders want a stop close to them. Cities like to control growth. These factors are controversial because they mean deliberately making the transportation worse to meet another goal.

I give this factor only minimal coverage here, even though such factors actually contribute a great deal to debates on cities and transportation. They are worthy of their own articles, but the key is to understand when something meats a transportation goal, and when it modifies transportation as a means to promote a non-transportation goal.

Reduce other negative externalities of travel

Negative externalities are costs born outside the system. Pollution is just one, though it's the one we talk about most with transportation. But there are others, including noise, the safety of those not using the transportation, and harm to the character of our streets and neighbourhoods.

One mode should not unfairly degrade another mode. Society has a rule of making sure all road users get along and don't interfere unfairly with others.

Treat people equally

People aren't so good at that so society tries to do better. This can include making sure low income people can travel, as well as people with limited personal mobility.

Ensure equal transportation availability for lower income people, seniors, the disabled and minorities

In many cases public transit is cheaper than private, and is subsidized, sometimes heavily, to become the only affordable means of transportation for some people. Societies don't like to leave anybody unable to move.


This is a meta-goal, though it ties into many other goals. Society is going to invest immense money in transportation systems, and it needs this investment to be productive long term. This means technologies which are flexible and can adapt to an unknown future, and certainly not that which will become obsolete quickly or before its planned lifetime.

As an example, monorails seemed very futuristic, but there's almost no way to adapt them to future needs, you will never run anything on the monorail but vehicles designed specifically for it. Even changing lines to expand a system is troublesome. BRT, on the other hand, builds a lane of pavement that can be used for any pavement based vehicle now in use (as well as pedestrians) but also one's not yet invented or available -- it can even be converted cheaply to bike paths, pedestrian courses or plain roads, which a monorail can't. In general, this goal encourages simplicity rather than dedicated solutions which can't be changed without complete replacement.

The lower level goals

Of course, transportation itself is a means rather than a goal. Our real goals are more like the famous hierarchies of needs from Maslow and others, but the reality is we often have to travel to get food and things, to socialize, and to earn the money to get those things. As such, transportation sits as one of the "fundamental means" of life in modern society. While our true goal might be the things we buy with money, and earning money the means by which we buy them, this quickly takes us to our world where most (but far from all) means of earning money involve travel by somebody. Socialization in-person, with other than the people you live with also requires travel by somebody.

Now that we've got the goals...

I welcome suggestions of additional goals we have in how our transportation works. But not things which are actually means to deeper goals. In addition, if you can argue some of these goals are actually means, point that out. It could be said that there is only one goal -- satisfaction -- and that goals like speed and reliability are just means to that, but I have selected these goals as a happy medium. If we just have satisfaction with the trip as a goal, it doesn't teach us very much about how to attain it. At the same time there certainly are transportation systems which lack some of the goals but still satisfy their users, in some cases because they haven't learned to want more.

With the goals established, we get to examine how well all the existing transportation modes -- walking, cars, taxis, buses, bicycles, private scooters, vans, trains and boats -- along with the new modes -- VTOL aircraft, ride-hail, bikeshare, dockless scooters, delivery robots, robotaxis, robovans and more -- fit with these goals. We can also examine how private right-of-way vs. shared public right-of-way satisfies these goals.


You forgot *clean*. In Tokyo, I can sit on the seats in the subway. In New York, not so much. (And that's without considering the squalor of the subway stations in NYC). This is not to be confused with "healthy".

This also applies to bicycling -- I don't want to ride my bike in the debris that's been pushed to the side from the automobiles. When I'm walking, I don't want to deal with being splashed by cars driving through puddles, or have to navigate piles of snow or icy sidewalks.

And "comfortable" covers more than just the transportation -- it also covers getting to the transportation and waiting for it. Especially when the weather is very cold or hot or pouring rain. Which also raises the issue of multiple modes (walk to subway; bike to bus; train+taxi; etc.), also issues such as parking (both car and bike).

Yes, the pleasant/comfortable ride includes all of these. And quite a few more. I mean one could probably write a long article about all the different variations of how pleasant a trip can be -- bumpy, noisy, crowded, smelly, pushed, harassed etc.


Brilliant article!

To the traveler's goals, I would add easy transport and, possibly storage, of their goods/possessions. This probably isn't a must-have, but convenience of being able to carry groceries, golf clubs, whatever, is one reason personal cars are so popular.

Will add

Not directly involved in movement, but necessary to consider any time one is away from home, whether via public transit or private vehicle.

This is one of the many comfort factors that I have not listed. These include all manner of things from plushness of the seats to cupholders and everything cars compete on, to room, presence of other people, bathrooms, lighting, recline for sleep, noise, smoothness of ride, you name it.

I'm not sure "safety" is nuanced enough. Either that, or there should be another category for control over safety.

As you note, people are willing to trade off some safety for shorter, more predictable travel times when it comes to driving less carefully than they could. On the other hand, we're willing to undergo very large (and to an extent fairly unpredictable) travel times to get very little or even no actual safety when it comes to air travel. There are many attempts to explain this, but personally I think the right explanation is that people are especially sensitive to a lack of safety when they are not in control of the safety.

This is a strike against mass transit, but it's also a strike against robocars.

Maybe as with the travel times, it's not just increased safety, but also predictability over safety.

I'm not sure exactly what it is, but I feel this way myself, even. Being in an unsafe situation *and* not being in control of that situation, is especially frightening.

The nightmare of airport security isn't seen as a choice by most people. Oh, they will often say, "I guess we need to do this to keep travel safe from terrorists" but not because they made a choice.

An interesting thing would be to test if people don't mind if they get a slow Uber driver, when they are not particularly in a hurry.

Are you saying that you reject the premise that people are often willing to compromise on safety when they are in control, but not when someone (or something) else is in control? Or is it just that one example of airplanes that you don't agree with?

No, I was just saying the airport "safety" tradeoff is a very different one. I do think people are more willing to take risks personally than to have others expose them to risk, but I don't know if that's been quantified. People want safety from their transportation (even, though much less so, in their recreational transportation like dirt bike riding) and there is no doubt it is a goal. The issue I brought up is simply that while everybody says it is goal #1 it's not clear if it really is, and people certainly trade it off against other goals.

I see. I think you're right about that, although I'm not sure that it even can be properly quantified, because people's preferences don't always make sense from a statistical point of view.

As society grows ever more affluent in aggregate, we demand more and more convenience and personalization in goods and services. So the future of transportation is not stuffing people in aluminum tubes and shuttling them around at the whims of bureaucrats and politicians. Instead, consumers will the demand privacy, speed, and convenience of "robotaxis" especially in urban areas. Imagine small electric vehicles moving individuals from where they are to where they want to go quickly, privately, and conveniently. When not in use, they can be stored and charged offsite (e.g. industrial areas).

People definitely like personal transport, no question. However, at rush hour, there is not enough room to move them all on the roads. The skies may offer an answer, but it is not likely we would build enough roads to do that, so the answer is likely to be one of:

  • Some people will share vehicles
  • Some people will avoid commuting at rush hour (via telecommuting, or shifting their commute.)

Now the question becomes, how do we share vehicles, and what moves people to share rather than the preference of personal transport.

There are many answers, including cost, better access to right of way, allocation (no more cars may use the roads than they have capacity for, forcing some people into the above choices) and others. One of the best answers is to make the shared experience really, really good so that it takes little effort to convince people to use it.

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