The role of transportation technology, specifically the fastest transportation that the masses can afford and the infrastructure permits, is a pervasive but often unconsidered factor in our daily lives, influencing our built environment and even our social and economic opportunities.
After rapid advancement in the 19th and early 20th centuries, the state of the art in mass transportation for daily commuting and recreation has stagnated for over half a century in a range between, on the low end, automobiles on freeways that average perhaps 80 miles per hour in free-flow traffic conditions, and on the high end large subsonic airplanes (jumbo jets) averaging 600 miles per hour.
This dictates quite a bit; perhaps most importantly, it means the maximum range one can be from services and workplaces and still have easy access to them has also stagnated for half a century. Most people seem to be willing to commute half an hour or so each way to work. If walking is the fastest method as it was until the advent of the railroad and later the automobile, housing further than half a mile away is not a viable option; by contrast, if one can go 50 miles per hour in a car, one may locate oneself 25 miles away. This has influence on the built environment; it is a pattern throughout human history that people tend to locate in the least-dense environment that is still viable for meeting their needs and wants. The half-mile commuting radius means the people dependent on that service must all cram themselves within less than 1 square mile of land; a 25 mile radius, by contrast, means the same population may spread themselves across almost 2000 square miles of land. This is a very large difference, and is the primary reason why even very large cities can harbor most of their population in suburban tract homes with quarter-acre lots today, a feat that would have been very difficult before the advent of the railroad.
This increases the effective supply of land by a factor of hundreds, if not thousands, opening up more natural and rural living for the masses even in urbanized societies. Half a century of stagnation in speed also means half a century of stagnation in land supply within easy commuting distance; even worse, the lack of new freeway lane-miles and other infrastructure in the same period amid a growing population and economy has increased traffic congestion, thus actually decreasing speeds and the effective land supply. An improvement in transportation technology and infrastructure would reverse this trend and restore progress in the future. So, what would progress in this field look like? How far could transportation technology advance? What would be the effects on our daily lives?
An illustration, using Chicago as an example of a city center, of how much more area opens up with a larger easy travel radius – underlying map courtesy of NASA
Upgrading to Today’s State of the Art
The simplest way would be to upgrade highways to modern standards of speed and eliminate congestion by building enough space to absorb all traffic demand. The former is easy enough; modern standard-issue freeway pavement easily supports speeds of 100 mph (or even somewhat higher) in modern cars, which is about as fast as most of them can be driven comfortably. The latter is often dismissed as unrealistic, but demand for road space is saturated at some point, as the almost total lack of traffic congestion on two-lane rural highways demonstrates. Only a lack of will prevents cities from receiving the same benefits. This need not mean paving over buildings and cherished historic areas; the technical ability to dig numerous large tunnels has existed for a long time, and exit portals can be dispersed and made unobtrusive. Even parking can be accommodated completely underground, obviating surface driving in cities altogether. An entire plan to do this for Greater London, known as “Underways”, was proposed as early as the 1960s but obviously was never taken up.
In any case, the technical ability exists right now; the cost, while large compared to existing infrastructure, is smaller than many other existing government programs. The result would be the ability to drive 100 mph or even faster, perhaps up to 150 mph, on any highway without being obstructed by traffic. This is double what most are able to achieve today even without traffic; the gains from de-congesting traffic would be still greater. In the more highly congested regions it may quintuple commuting speeds.
2-5 times the commuting speed expands a 25 mile circle out to 50-125 miles; in other words, a commute of 50-125 miles would become no worse than a 25 mile commute is today. A 25 mile commute in this future would be no worse than a 5-12 mile commute today. This has relatively large implications for what one might call the “labor shed”, the area of viable commuting around a large urban area. The part of this region where residents commonly commute in reality is the “metropolitan area”.
Although half an hour is the average commute people tolerate, up to an hour each way is somewhat common. This averages 50 miles today, and indeed in the map of “metropolitan statistical areas” in the United States it is very common for the outer edge to be 50 miles away from the core city. Given 2-5 times the speed, this radius expands to 100-250 miles. If metropolitan areas expand so far, many existing such areas will blend into each other.
Circles of approximately 50 miles in radius against a map of metropolitan statistical areas in the United States, demonstrating the general rule for commuting – map courtesy of the United States Census Bureau
For example, Detroit, Lansing, and Grand Rapids are all within this radius, and would form one massive metro area covering southern lower Michigan. Charlotte, Raleigh, and Winston-Salem are also all within this radius, and would similarly form one large metro area. New York and Philadelphia, Tampa and Orlando, and Chicago and Milwaukee, would all also merge into one. It seems the entire concept of metropolitan statistical areas would begin to lose coherence at this stage, as the average one would contain multiple core cities that are each very independent according to the “contiguous urban area” measure. The “megaregion” concept would start to become more relevant given this jump in transportation technology.
And this is just for a jump of 2-5 times in speed, up to perhaps 150 mph at best. Even this modest improvement expands the labor shed’s area by 13-80 times. 80 times as much area is open for commuters to live in; a population that spread out now over quarter-acre lots could spread out over 3-20 acre lots in this future. Population densities of perhaps 2000 per square mile in today’s urban sprawl drop to 25-150 per square mile, which takes the sprawl of the future out of the urban range altogether. These are truly rural densities, all while retaining the same access to workplaces, amenities, and services enjoyed in suburbia today.
Not only services, but attractions would also open up. Viable day trip distance, where one can drive out to a destination, spend most of a day there, and drive back in the same day, is perhaps up to 200 miles today. 2-5 times the speed expands day trip range to 400-1000 miles. Atlanta to Washington and back again by car in one day becomes doable, as well as Chicago to New York and San Francisco to Los Angeles, among others.
Beyond Today’s Best: into the Near Future
This, however, is only the beginning of what may be possible in the future. Many cars today are capable of reaching 200 mph, the very fastest over 250 mph, albeit at very low fuel efficiencies that necessitate frequent (and time-consuming) refueling. Nevertheless, it isn’t much of a leap to imagine cars capable of traveling at 250 mph without much refueling. While this is still only 5 times the usual 50 mph long-range commuting average and thus the long-range and day trip distance would remain the same as above, it’s a full 10 times more than what is possible in congested traffic. Inside urban areas the main limit would actually become the maximum comfortable acceleration; at 250 mph it takes less than 3 minutes to travel 10 miles. Such speeds, whether achieved by car, aircraft, or rail transit, would enable any point within any dense urban area to be reached within a few minutes.
Speeds beyond 250 mph are quite possible of course. The world record speed for a ground vehicle is held by ThrustSSC, which broke the sound barrier and reached 761 mph in 1997; although not very useful on a highway, the vehicle shows a limit far higher than what most would contemplate. High-speed trains today, interestingly, go at the aforementioned 200-250 mph speeds right now, and up to 375 mph has been demonstrated experimentally. If 400 mph could be achieved regularly at an affordable price point, commutes could extend 8 times further than today, opening up 200 times as much area as today. At 400 mph 200 miles is the new 25 miles, and 400 miles is the new 50 miles. At these distances much of the lower Midwest could commute to Nashville or even Atlanta; Houston to Dallas, Charlotte to Washington, and Los Angeles to San Francisco all become easy and common commutes. Metropolitan statistical areas would at this point become mostly coterminous with “megaregions” and lose coherence. Instead a vast regional labor-shed would appear, each containing dozens of mid-sized to large cities.
At 400 mph, a day trip three hours each way, perhaps 200 miles today, extends out to a range of 1200 miles. Chicago to the Black Hills, Seattle to Yellowstone, and Washington to Miami all become easy day trips. From a central location like Indianapolis most of the eastern United States is within one day’s round trip at 400 mph. Similarly, from Salt Lake City most of the western United States becomes within day trip range.
Leaving the Ground: the Advent of Flying Cars
I suspect that 400 mph might be the best that is easily achievable with ground transportation on a mass scale, as that is close to the maximum speed achievable with maglev trains with current technology, which may become standard and affordable speed with near-future technology. While production-line cars are not yet capable of 400 mph, pushing the current state of the art in cars across the board could probably yield a vehicle capable of this speed. This also may become standard with near-future level technology. Anything faster than that is stretching it even under optimistic assumptions, and once you get to a large fraction of the speed of sound (and 400 mph is more than halfway to the speed of sound) it’s much easier to use aircraft than ground vehicles.
For that reason, by the time we achieve everyday 400 mph travel it will probably be accomplished by maglev trains for mass transit combined with small aircraft for personal transit rather than cars on highways. In addition to being able to go much faster much easier than a ground car, a flying car can also travel everywhere in a straight line; not needing to follow the winding path of a highway cuts travel times significantly, and also enables transportation over water, two rather large advantages. A disadvantage of mass personal airplanes would be the need to build runways everywhere, which would require even larger-scale infrastructure than the advanced highways mentioned earlier; aircraft capable of easy vertical take-off and landing would solve this problem and are a practical requirement for mass flying cars or personal aircraft.
This could take the form of helicopters, but a hybrid design would be much more effective. This was first proposed and successfully tested as early as the 1950s by the Fairey Rotodyne, a type of gyrodyne, which had both rotors (for vertical flight) and conventional propellers (for horizontal flight), before it was scrapped. If given more development, it stood a good chance of introducing short-range aerial transportation on a mass scale. Fortunately the spirit of the Rotodyne has in recent years been revived by Uber in the form of Uber Elevate, a project which envisions using aircraft with tilt-rotors (similar to the V-22 Osprey, using one set of engines rather than two) to transport passengers over short distances, particularly in congested urban areas.
Advanced personal Aircraft
Although the V-22 Osprey has a maximum speed of only 350 mph, the Harrier jump jet can reach 700 mph, so designing a personal tilt-rotor aircraft that can match or even exceed the speed of today’s commercial jets shouldn’t be difficult with near-future technology. This, if rendered affordable by further technological advances, would herald an era of personal door-to-door transportation at 600 or even 700 mph.
700 mph as the default cruising speed would expand half-hour commute range out to 350 miles. To illustrate how great this distance is, there are parts of Ohio within 350 miles of Atlanta; the entire Northeast corridor plus Toronto, Ottawa, and Montreal is within 350 miles of New York. One-hour commute range extends out to 700 miles. Chicago to Raleigh becomes a viable and common commute at this speed, along with Seattle to Salt Lake City. The eastern United States and Canada almost become one massive labor-shed, exceeding the scope of even the largest mega-regions.
Easy day trip range at 700 mph expands out to 2100 miles. This is a very large area; from Chicago the entire contiguous United States and all of Mexico is well within this range, along with most of Canada, including all of southern Canada. Parts of Greenland are just within this range from Chicago. The Caribbean becomes an easy day trip from almost anywhere in the eastern United States. Transatlantic day trips start to become viable at this speed in select areas, specifically Newfoundland to Ireland. San Francisco to Anchorage becomes a viable day trip.
Interestingly, Alaska at these scales starts to look rather centrally located. Although little aside from western North America and eastern Siberia is within day trip distance, a 6 hour journey, what one might call weekend-getaway range, includes northeast Asia, most of Russia, northern Europe, and all of the United States, Canada, and Mexico. It is perhaps for this reason that Anchorage today is the sixth-busiest cargo airport in the entire world; given mass personal aircraft the region may become an advantageous location for passengers as well. Some other regions now thought of as the back of the beyond start to look attractive at these speeds; Greenland, for instance, at 700 mph is within day trip distance of both New York and London, perhaps enticing super-commuters (people who commute multiple hours each way) to live there.
Aerial parking Garage
The advent of mass personal aircraft all buzzing through the sky like science fiction visionaries have dreamed about for over a century would have many advantages; for one, even the heaviest traffic in transportation corridors becomes sparse if it is spread across three dimensions rather than two as is the case today. The real bottleneck will come with landing at popular destinations, an aerial variant of today’s issues with car parking. Any viable tilt-rotor aircraft will have a much larger footprint than a car and will demand correspondingly larger parking areas.
Vast landing areas, somewhat like today’s airports, may be constructed outside cities, where mass transit might ferry passengers to downtown. If highway and parking infrastructure is built out before flying cars become prevalent, conventional cars might ferry them to the pre-existing “underway” tunnels for entering the city. That would be a real switch: cars as we know them confined to within cities rather than outside them!
However, with projects like Uber Elevate already in the works a direct transition to mass personal aircraft rather than one preceded by an intermediate dead-end pathway of building out advanced freeways and “underways” seems the most likely outcome as we go into the mid to late 21st century. Skyscrapers built to function as parking garages for aircraft would work far better than underways in this future, since many levels of aerial traffic could be flying in and out simultaneously; this is simply not possible with an underground installation.
These aerial parking garage skyscrapers would be, along with underways, the ultimate solution for reconciling urban density with accessibility. These garage levels could even be built into new skyscraper construction, enabling their residents or workers to come inside the building directly from their homes or other destinations. Conventional airports will still have their place as a landing zone for much more massive aircraft transporting large numbers of people, likely at high-supersonic speeds to maintain competitiveness against personal aircraft (much as high-speed rail competes successfully against cars now), but even these passengers may be ferried downtown by air in smaller bus-size tilt-rotors directly to their destinations, at least if maglev rapid transit isn’t predominant for such uses.
Supersonic personal Aircraft
Even better, this sort of infrastructure, once built out, has massive upgrade potential. Past 700 mph the entirely new realm of the supersonic awaits the masses. Although I am not aware of any designs for personal or even mass-transit supersonic VTOL aircraft, there are designs for military use, indicating that it is technically feasible. Concorde-style speeds of around Mach 2 are likely in the earliest versions, perhaps (as a wild guess) arriving for mass use in the late 21st century.
Mach 2 is around 1300 mph, so the distances are correspondingly doubled. Half-hour commute range becomes 700 miles, and hour-long commute range becomes 1300 miles. This puts the United States and Canada in more or less the same labor-shed. A commute from Anchorage to Vancouver becomes viable. Easy commuting range for Chicago extends out to Salt Lake City at Mach 2. Speeds faster still may be achieved; advancement to Mach 3-5 is relatively easy once one has achieved Mach 2, if the history of supersonic passenger jets is any indication. The top end of this range, Mach 5, is 3800 miles per hour, opening up a half-hour commute range of 1900 miles and an hour-long commute range of 3800 miles.
For perspective, 3800 miles puts all of North America, the west coasts of Europe and North Africa, and northern South America within an easy commute of New York. Anchorage is within an hour’s flight from all of Canada and the United States, Siberia, Japan, and Korea. The United States, Canada, all of Europe, and most of Siberia is within an hour’s commute from Greenland. This is an immense easy commute range.
At Mach 5 easy day trip distance expands to an incredible 11,400 miles, almost half the Earth’s circumference. This means that any point on the Earth may be reached within a bit more than 3 hours at this speed, opening up the entire planet to day trips. By extension super-commuters may live anywhere on the planet and commute to anywhere else on the Earth every day. This may be the ultimate in mass mobility, but there is a way with near-future technology to go even faster: spaceflight.
The ultimate in personal Transportation
Hypersonic travel, beyond Mach 5, is possible but very difficult within the atmosphere due to the tremendous heat generated by atmospheric friction. It’s much easier to attain such speeds outside the atmosphere in outer space, which permits much greater speeds anyway. Suborbital flight is sometimes suggested as a cheaper form of spaceflight, but achieving suborbital flight requires most of the change in velocity and complex engineering orbital flight does, so any suborbital flights in the future will likely be using vehicles also capable of orbital flight. It is for this reason that SpaceX is considering using its Starship for point-to-point Earth transportation in addition to the originally intended Earth-to-orbit and interplanetary use.
At minimal orbital speeds the Earth is circled in 90 minutes, meaning it takes 45 minutes to travel from one point on Earth to any other point using an orbital spacecraft. A suborbital flight may take somewhat shorter or longer, but it is clear that travelers using spacecraft like Starship or spaceplanes like the Skylon any place on Earth can not only be reached in 3 hours but under 1 hour. This is the ultimate limit using near-future technology, and it opens up mobility to a degree that can be hard to imagine. If this technology, ideally in the form of a personal spaceplane to fit into the flying car or personal aircraft infrastructure, becomes affordable someday the other end of the Earth will become as easy to get to as a place 40 or 50 miles away is today.
That will be the true culmination of globalization and mass mobility, a point far removed from where we stand today yet visible peeking over the horizon. Bold visionaries, inventions, and investments will be required, but with luck this vision may be realized within our lifetimes if we have the will to do so.