One thing that the article doesn't mention but was still an important factor in the streetcars' demise: the need to replace the capital stock. Things like tracks and trains don't last forever, and eventually you have to replace them completely rather than just doing normal maintenance, but that only happens every few decades. If you spread out the replacement, it's not so bad, but I suspect many streetcar companies didn't bother doing that through the 20s since they were still relatively new (and 30 years counts as "relatively new" for tracks). But then the Depression hit and funds became hard to come by, followed by WWII which led to a surge in ridership but a shortage of materials. By the end of the war, not only were streetcars facing increasing competition from cars driving on new highways, the systems were also physically worn out and needed to be totally replaced. Indeed, this is exactly what happened to the Pacific Electric's Long Beach line, just with a gap of 29 years between closing the old line and opening the shiny new one in exactly the same place.
Today you have streetcars ("trams") in more than 200 European cities and they have also needed replacements and been upgraded from time to time. So why did streetcars thrive in most of Europe, but barely survived in America? We had depressions and world wars in Europe too.
The primary answer is buried in the article, in passing: "And when even 10% of Los Angeles’ population got behind the wheel, their presence so slowed the streetcars, which lacked their own lanes, that they could no longer make their schedules, and their level of service declined overall."
European streetcars typically have separated lanes and loading areas and thus don't mix with automobile traffic. That way they aren't in conflict. When roads had largely low speed and uncontrolled use, streetcars worked fine because people were used to and able to stay out of each others' way. The automobile was dramatically faster and more dangerous, and the laws and infrastructure were gradually adapted to it (e.g. traffic signals, left hand turn rules etc).
Streetcars in the US, and I suspect in other places where they have failed, had to intermix with automobiles, which lead them into a deadly spiral.
The other factors mentioned in the article (reluctance to spend, reluctance to run a centralized system, regulation, etc etc) applied in Europe too -- we have a survivorship bias when we see the streetcars in Europe. Look at Berlin as a great A/B experiment: in the west the streetcars were torn up while in the east they were retained. I much prefer living in the east (today!! not under communism) because the Straßenbahn is so convenient. My kid took it to school.
Some streetcars survive or have been revived in the US -- it's called "light rail" because I suppose "streetcar" is a laden word. They pretty much all have dedicated right of ways, and if not (I'm thinking of parts of San Francisco's MUNI) they have dedicated loading areas and exclusion zones -- except for cable cars :-)
Yes, and not only that, American streetcars had often gotten rights to build track from the city in return for responsibility to repair the streets the tracks were on. Which was a fine deal when there was only foot and horse traffic, but put them in an untenable situation when suddenly cars (which cause much more wear and tear on streets then people or horses) became popular.
That has more to do with what happened after the war: America was doing quite well and had piles of money to spend on roads and cars and suburban houses, while most of Europe was pretty devastated and had to spend everything just on rebuilding, without much left over for things like cars and highways, and so focused their investments on public transport. Even so, a huge number of European cities did end up abandoning their streetcar systems, either because the city was small enough that buses were deemed adequate or because it was big enough to have a metro system. The other big exception to the general trend was the Communist countries where public transport was encouraged over private automobiles for a range of reasons. But even in many of the ex-USSR countries, there has been a similar trend of streetcar infrastructure wearing out and getting abandoned rather than replaced.
UK was a financial wreck at the end of the war, yet still fully committed to internal combustion. We did irreparable damage to the rail network, abolished all tram networks except one, and built huge car-centered networks (spaghetti junction in Birmingham being the most people unfriendly example I know of, especially the residential streets in the shadow of the raised roadways).
All it took was a look across the sea to the Netherlands we'd see integrated bus/rail/tram terminals and some degree of planning and intelligence still being applied to transport. We got to sit breathing traffic fumes.
That makes me think it was more about politics and policies than money.
Trams completely died out in the UK through the 60s. Just one town, Blackpool, kept them. This was around the time Beeching was making devastating cuts to the UK rail network. The belief seemed to be that cars would be the answer to everything making rail and trams go the same way as canals. Until only a few years ago the trams in Blackpool were running on rolling stock mainly from the 30s and 40s, with just a few bus-bodies from the 90s. They ended up being a living museum and they even bought up old trams from other regions.
A few years ago they rebuilt the entire network with new modern stock and track, with new disabled friendly stops. It's sort-of a success. They halved the number of stops (due to needing platforms for disabled access), so it's less convenient. They increased the prices, making it more expensive than the bus following the same route.
Many other UK cities have brought back modern tram networks, with mostly great success. It's often proved horribly expensive to do - Edinburgh being the example of how not to buy a tramway. The UK is also bringing back some of the axed rail networks as roads become increasingly gridlocked. Of course this is expensive to do, especially as sections of many lines have now been built on.
Other parts of Europe, though not all, seem to make consistently more intelligent transport choices, and have long provided more integrated transport solutions.
Just yesterday there was a post on here about London's bus numbers, those had been inherited from the horse and cart days, been used on horse drawn trams, been used on electric trams, been used on trolleybuses (trams with little rubber wheels instead of proper steel ones) and now used on regular bus routes. Seems that London upgraded transport stock to get rid of trams without there being some huge conspiracy. A plausible scenario could happen elsewhere.
In case you've never used one, a trolleybus is actually much closer to a normal bus, but runs from overhead electric wires.
They're still used in some cities in China and eastern Europe. They're quiet, have flexible routes, and zero pollution in the City, and are lightweight.
Streetcar companies in the US almost universally were under regulation where they were legally required to have a fare that could not support the maintenance of the system.
It wasn't that straightforward in Europe either. E.g. in Munich, the tram network was reduced until the 1990s as it was thought underground trains could replace it. That turned out to be insufficient, so now we have both. But yes, it involves significant public spending.
Europeans do not have significant amounts of space to build housing supplies, that's why space/m^2 is much higher than here in the states, witness San Fancisco's trolley system that caused suburbanization (or at least enabled it).
Gas Taxes in Europe are double than here in the states[1], US gas is taxed at relatively low rates when compared to other nations. Used as a user tax here in the states, its predominant purpose is to fund roadway improvements and maintenance; however, it is used to fund transit and other items. In Europe, the higher gas tax is used to drive (good one Agustus) less travel and subsidize rail lines.
The trams / streetcars in Europe work because the suburbanization was stopped by high government taxes and forces the populous to pay more for a lower comparable standard of living.
*Edited for why, if you disagree, please provide an alternative opinion. I have taken the time to provide a discourse, if a downvote to it is necessary, then please provide a reason.
Suburbanization was heavily subsidized in the US for a variety of political reasons. That just happened to line politically connected peoples pockets. It's actually terrible from an economic standpoint.
The US also focuses on extremely local school funding which promotes heavy economic segregation and is extremely harmful for the overall economy.
PS: Early on post WWII it was assumed to be a good defense from the at the time low yield nuclear weapons. But, this is hard to trace back and might not have had significant impact.
I did not downvote you but I found your post was reasonable (although I don't completely agree with it) until your last sentence and the "lower comparable standard of living".
Europe also got bombed to pieces, major cities had to be rebuilt anyway, and Eastern Europe didn't have the wealth that post WWII-America did, so trams were more an essential service than a nice-to-have thing.
European cities also came into being before the car did, so their layout is often more streetcar friendly: Higher density, no room for six lane highways, etc.
Tracks do last forever with normal maintenance and partial replacements. Rails do wear out, and are constantly being realigned and replaced, as well as ties, ballast, signaling etc.
But your point about rolling stock is correct. The PCC street car was designed in the 30's to address that, being a mass-produced, modular system.
Also, the European streetcar systems went through the same economic hardships (and some much larger ones - the wars), even using the same PCC cars, but still thrive to this day.
So it is more about a policy driven by lobbying and intervention from auto manufacturers than purely business model and economics. Robert Moses had a really big hand in this as well...
street cars, falling under the light rail category, suffer a similar problem to heavy rail solutions. they are expensive to adapt to changes in usage. if the needs of the people change and the street car wasn't going that way you can't fix it quickly or cheaply.
While this is a bug, it's also one of the most unnoticed and unspoken about features.
If I'm looking for a house and access to reliable public transit is important to me, I'm going to want to buy in an area well served and expected to be well served 30 years from now as well.
Track and train stations mean this is likely to be true. At least far more true than a bus route.
In this manner city planners can't pull the social contract rug out from under you as easily.
Very true, that's why they can't be a single solution to transit problems. They are good for serving some areas, and work well when mixed with urban rail, suburban rail and buses.
Use rail for high-density areas that change only over multiple decades, and buses for low density, mutable areas.
Tracks last anywhere from 30 to 40 years at most and then they need to be replaced. 30 years isn't long for any given line or right of way, but it's near end of life for tracks.
In any city with a streetcar system these are constantly being replaced, bit by bit, to keep the system working.
Certainly true here in Portland, OR. The oldest sections of the regional light rail system were constructed ca. 1980. There's a project starting next month to replace the track (along SW 1st Ave) which has caused many delays and considered a major hazard to reliability.
Rail/streetcar public transportation is quite popular in the region and well-used, though it doesn't stop auto traffic from being a nightmare with increasing frequency.
Detroit sold its streetcars in 1956 to Mexico City. Today some of those cars are still being run in various places in South America and in San Francisco!
The big mistake was in assuming a public transport system could be profitable. Almost none are. Many of the best public transport systems in the world barely scrape by and are continually at risk of collapse. The benefits to businesses, improved mental health of passengers, reduction in pollution and traffic are all external benefits to the community which are not accounted for in the transportation systems budget. Some governments recognize this and so continue to subsidize their transportation systems. Countries like the US which demand that everything be run like a corporation will continue to fail to realize any benefit removed a step of two away from this quarter's profits.
Well they would most all be in better off shape if they did not waste their resources on heavy rail. About the only need for such is to airports, past stadiums, and possibly central commercial districts. However their cost per mile to install, maintain, and operate, all wreck budgets. Worse many bus routes get co-opted to serve rail nodes which worsens the bus experience and not really help the rail.
The key reasons buses are better is that they can go where people need to go and are not locked in to where they are built out at.
The sad part is that in many parts of the world ridership doesn't increase much with the cost going down, even to free. hopefully autonomous fuel cell / battery cars and buses will make point to point more manageable and viable overall.
I'm guessing you mostly mean light rail, since there's not a lot of money going into urban heavy rail. There are a couple of reasons why these can be better than buses:
- You can invest around them. Because unlike a bus, a tram can't just be upped and moved somewhere else developers are able to build housing and services confident that there will be service.
- They are easier to segregate and run at speed so that you can run limited stop services that are credible. I suspect this is what you are getting at with airports, but I'm not sure why you think an airport is the only reasonable use for fast limited-stop operation
- They can carry more people easily. 2 or 3 car trams are the norm, and the smoother ride and increased safety means that it is much safer to carry lots of standing passengers
- People like them. You can actually get people out of cars onto a tram, where faced with a bus they will assume that it is going to be dirty and they will be robbed (however untrue that is)
Rail is much more reliable then buses since it doesn't compete with car congestion, plus you can make it run much more frequently, both of which are very important for adoption.
> Rail is much more reliable then buses since it doesn't compete with car congestion
That is not true in some places. MN built its light rail in such a way that interacts with normal traffic quite a lot (including killing people because of a really badly designed interaction on a former turn). I get the feeling someone in the planning office had taken no lessons from street cars.
You may be assuming 'public transport' = government-run monopoly transport: government-run services almost never make money, but that's not a transportation issue. This econtalk podcast has a interesting discussion about how Chile moved from private to public: http://www.econtalk.org/archives/2008/07/munger_on_the_p.htm...
Businesses, especially consumers, are helped more by the mobility of a car than public transport
>improved mental health of passengers
1. This is not an external benefit. This, if true, should mostly be reflected in people's willingness to take public transport. Of course, people taking public transport are in my experience usually of the most dubious mental health. So that's concerning.
> reduction in pollution and traffic
Fair points.
Traffic is by far the best case for running public transit at a loss, IMO. Though it must be weighed against spending that money on more freeways.
There are benefits, though not as many as you are listing, and we should be weary of running them at too much of a deficit.
In general the idea of running things as a business is not to say they should be run at a profit, it's to say they should be run efficiently like a free competitive market typically does.
This is not an external benefit. This, if true, should mostly be reflected in people's willingness to take public transport. Of course, people taking public transport are in my experience usually of the most dubious mental health. So that's concerning.
What you'll find is that people use public transit in cities where its convenience outweighs the convenience of a car. In cities where that is untrue, only those who can't afford a car use public transit.
Which is to say that public transit isn't somehow magically better than auto travel by virtue of some fixed aspect of public transit.
It's better when it's better, which may sound like a tautology, but is actually just kind of an obvious truth, evidence for which is available all over the world.
I'm not sure it's just convenience but rather some combination of convenience, cost, and just preference. But your basic point stands. The vast majority of people will use public transit when it works better for them personally given their other options on a given day. This tends to most commonly occur in cities that have relatively good transit systems (for the trip in question) and congestion that makes the same trip by car relatively unpleasant/slow.
You need to do some travelin'! Your perception of mentally questionable people taking public transportation may well apply in the USA, but in other countries it's simply not the case.
In big Russian cities it is way more convenient, cheaper, quick, and as pointed out -- mentally relaxing -- to take a tram or subway than to drive your car in the insane traffic. The clientele on said public transport are, for the most part, friendly, and you will see men scrambling to help old ladies or women with strollers onboard.
In general the idea of running things as a business is not to say they should be run at a profit, it's to say they should be run efficiently like a free competitive market typically does.
Sure, but the alternative to inefficient government spending on mass transit isn't some free market solution; it's inefficient spending on automobile infrastructure.
Do governments have to be inefficient? Can they be designed better?
In general, a free market competitive approach is always preferable where possible, but I think there is room to add better incentives in government as well.
> Businesses, especially consumers, are helped more by the mobility of a car than public transport
This assumes that everyone has access to a car, and that all automotive commutes are possible during "rush hour". Many businesses directly benefit from public transportation by expanding the labor pool to those who would otherwise be unable to commute.
The loss of the Pacific Electric system was tragic. LA is currently spending many billions to re-build what was lost, but we're doing a good job so far:
- The Expo light rail line is scheduled to open 5/20. This is the first rail line to go from downtown to the ocean since Pacific Electric.
- The Purple line (HRT)--formerly the "subway to the sea" until budget cuts caused it to be trucated to West LA--is the first east/west fully-underground subway to go from downtown to the west side.
- Metro's R2 plan[1] will invest $120B to construct new rail lines such as the Sepulveda Pass tunnel (bypass the infamous 405 freeway), West Hollywood light rail (one of the most walkable, transit-friendly areas in greater LA), direct rail access to LAX and more.
It's an exciting time to be an Angeleno. I have no doubt that--if these projects aren't cancelled--it will be transformational for our city.
One factor that this article doesn't mention is that many streetcar companies were locked into contracts that prevented them from raising fares above 5¢. National City Lines didn't come in until well after problems had already started. (Pulling that from here: http://www.vox.com/2015/5/7/8562007/streetcar-history-demise )
Was it physically easy to raise prices by a penny?
IIRC, there was an account of an issue with Coca-Cola's vending machines and them not wanting to raise prices and finding all kinds of convoluted workarounds, including asking the treasury to issue a 7.5 cent coin.
Recently Paul Krugman in NY Times made an insightful point I think: The most efficient transportation system in the world, is the ELEVATOR.
So just build taller buildings in a small area like Manhattan, there is plenty of space up there, it is cheaper that way and no need for roads and automobiles to move from one floor to another.
Living in a city is more humanistic anyway because there are more humans around you. There is no reason not to grow food in the sky-scrapers too. The only reason it is not done more is the zoning laws, which should be changed.
Efficient by what metric? By energy usage, sure, but the one metric that seems to override all others in the US is capex, not opex considerations (which over the long haul can overshadow initial capex acquisition costs).
The rule of thumb I've heard about construction is stick-built SFR is considered relatively baseline cost. Multi-Family Residential (MFR) with a few stories that requires some more robust structural elements is about 2X SFR per square foot. Mid- to high-rises are about 2X MFR (4X SFR) and up per square foot.
Economically living in high-rises is a non-starter in most of the US for many working-class and middle-class families, and you won't see Krugman's touted beneficial effects unless that middle of the population bell curve is in high-rises. I advocate dense urban development, but I have yet to figure out how it can be economically implemented without compromising quality of life, especially with the multi-decade long asset inflation we're experiencing in real estate that is ongoing.
We tried this - most urban centers in America are designed around elevators (and little else), and they've largely been failures that have been defined by blight, decay, and crime.
"Just build tall buildings" is a necessary but insufficient condition for an effective city. Manhattan works not just because it builds up (in fact many parts of it are limited to 6-story buildings) but because it has mastered the complexities of creating livable, workable spaces.
The other downtowns across America saw Manhattan, and took only "build tall buildings" away as a lesson, and they are for the most part deserted, ill-occupied spaces. Simple density and height is not the most important factor - it's not even among the top-10. "Manhattanization" became a dirty word across the country not because Manhattan is bad, but because so many places copied it thoughtlessly and incompetently.
A study of what makes New York City tick that examines Midtown over long-standing neighborhoods like Greenwich Village, the Upper West Side, and even more outlying ones like Harlem and Washington Heights, is doomed to fail, because you're seeing a complex, functional city and the only lesson you're seemingly taking away is "density = good", despite nearly every other urban center in the US being evidence otherwise.
tl;dr: Density is a necessary component of a functional city, but you don't need Midtown Manhattan-level density, and having density is not enough. High-density failed urban spaces are a dime a dozen.
[edit] Side note: elevators aren't actually very efficient at high density. They are great for low-mid buildings because they add a lot of floor area and don't occupy much space themselves.
For very tall skyscrapers it inverts - the number of elevators needed to properly serve the building starts increasing dramatically, eating up valuable floor space. There is a level at which you lose overall floor space for each floor you add to the building.
Some of the supertall skyscrapers currently in existence/being built are in fact taller than they economically should be - and this is subsidized by pride, ego, government, rich benefactors, or some combination of the above.
Tall skyscrapers make all kinds of optimizations to minimize this - destination-based elevators (where you punch in your destination before getting in) are popular, as are express elevators segmenting certain floors, but all of these grant modest gains in elevator capacity at best, and in modern times skyscraper heights are limited not by materials or architectural engineering but by this function of elevators vs. floor space.
It doesn't help that most cities outside Manhattan have parking requirements and often quite high ones, to the point where the parking for an office building takes up as much floor space as the offices themselves. And since elevators can't really transport cars very efficiently, your 100 story building will need to be surrounded by 10 10-story parking garages (or, more typically, you'll have a 30 story building with lots of surface parking around). If you factor in all the surface parking, you don't end up with very much density in the end.
> "If you factor in all the surface parking, you don't end up with very much density in the end."
More important than the reduction in density (which IMO for the most is not actually particularly bad), is the disruption in the street graph that parking lots represent.
Parking lots are awful places that are psychologically destructive on top of being literally hazardous to pedestrians. A parking lot is a good way to make sure you remove any trace of pedestrian travel in the area, and they represent black holes in the street.
One thing I alluded to in the earlier post is that graph connectivity is tremendously more important than density. If the street graph is disconnected (or just too difficult or hazardous to traverse), people will stop doing so, and there goes your urban life.
Small American towns (that resisted the suburban blight of the 50s) have very low density but manage to be extremely livable and functional by virtue of being well connected. Density is truly a red herring - livable, walkable spaces can be created at most densities short of completely rural.
Some New Urbanist developments have moved towards a model where the buildings directly face the street with parking lot "courtyards" in the middle - this model works. It's still heavily dependent on car culture, which is unfortunate, but is tremendous more functional than the suburban American status quo that is the opposite arrangement, where parking lots face streets and there might as well be a cavernous canyon between the sidewalk and the building (if there even is a sidewalk).
Absolutely. One thing that I've noticed personally (and that studies confirm) is that the distance I am willing to walk depends a great deal on what walking is like: whether it's interesting, safe, etc. Parking lots are thus a double whammy, because the both push actual destinations apart, and reduce the distance that people are willing to walk. And if nobody's walking anywhere anyway, why bother building tall buildings in expensive city centers instead of cheaper ones in suburban office parks?
Since you mention New Urbanism, have you heard of the Old Urbanist movement? New Urbanism is an attempt to return to 19th century American patterns, while the Old Urbanists advocate going back to an even older pattern of low-rise and mid-rise buildings on really narrow streets, which is a pattern that has worked well for millenia, and indeed still works well in places like Japan. The narrower streets mean there can be more of them for the same usage of land area, which can mean a much better connected network at a pedestrian scale.
Hopefully skyscrapers will build more inter-building bridges in the future. I wonder if the confluence of telecommuting, robotic goods delivery, and the penchant for urban living might mitigate the skyscrapers' elevator-to-floor optimization challenge by shifting the utilization pattern to one that sees more inter-floor and inter-building travel instead of ground-to-floor travel. There has to be some fascinating data collected by the elevator companies on the statistics of elevator service (mass, destinations, etc.).
> the number of elevators needed to properly serve the building starts increasing dramatically, eating up valuable floor space.
I assume that assumes that every time I take the elevator I am going take the trip to the ground floor to exit the building. But work and stores and cinemas could be on floor 40 of an 80-story building meaning the average distance traveled in elevator would be shorter than if I need to get out to the street every time.
> ... are in fact taller than they economically should be
No doubt there is an optimum height somewhere there. And it's not only about building up, but building closer in general. When people work and live closer together there is less need for transportation overall.
Is there really no reason not to grow foods - is this a researched opinion of yours or just conjecture? The last article posted on HN about the trend of rendering skyscraper designs with greenery noted many of the problems with actually building them (irrigation, water proofing, the ability to support the extra weight of the soil/plants, sunlight/shadows, high winds, etc), I would imagine the problem being even greater if you had to grow edible foods rather than just a green plant.
Well yes I may be wrong on that, maybe its best to grow the greens outside Manhattan. It is a technical issue which should be explored if it seems economically feasible. But surely it's a good idea to grow something on the roof which grows there, I read it also helps insulate the building requiring less AC.
I've just (re)watched with my sons the movie "Who Framed Roger Rabbit?".
SPOILER ALERT!!!!!!!!!!!!!!!
In the end, the detective said the villain must be a cartoon, because just a cartoon would have the stupid idea of replacing the efficient and cheap L.A. public transport system, and to build highways.
Modern urban planners can take a lesson from this. People abandoned light rail in Los Angeles because they preferred their cars. A car provides anytime, anywhere, personal door-to-door transportation versus the fixed-time, fixed-place, mass transit system that only takes you part way like fixed rail. Light rail will die a similar death in U.S. cities, especially when self-driving cars decrease traffic by a significant amount in the near future.
That's only true if your origin and destination are both surrounded by parking which makes them places not worth visiting. The thing about trams is they enable a full urban environment of places people actually want to be.
No, most people do not enjoy strip malls in their own right. However, a great many people prefer spread out neighborhoods and exurban areas within driving distance of those strip malls over denser cityscapes.
Everyone is welcome to the life they prefer, but as for the actual urban areas I'd prefer to see some efficiency. The subsidies we currently pour out to the great many people you describe are immense.
> especially when self-driving cars decrease traffic by a significant amount in the near future.
This is a fallacy - self-driving cars may reduce car ownership and may reduce traffic fatalities, but they could only reduce traffic if speeds were extraordinarily high.
That _might_ happen, but it'd also make every street a freeway. It's unlivable, and I will fight against that world.
>This is a fallacy - self-driving cars may reduce car ownership and may reduce traffic fatalities, but they could only reduce traffic if speeds were extraordinarily high.
That's not true at all. A ton of traffic congestion is caused by people making suboptimal decisions in traffic. Blocking intersections, not merging properly, stooping and going instead of coasting at a set speed, etc. really reduce the speed of traffic.
If you created a self driving only traffic system that guided the cars in an optimal path and speed you could increase traffic throughput by a lot.
But the current generation of self driving cars aren't even close to that task. If anything they will clog traffic even more when they panic and stop in the middle of traffic. That prevents accidents but it also will clog streets during rush hour.
Not sure why are are getting down voted as you are correct that people making sub-optimal decisions while driving in traffic. I remember watching a video of people driving in a circle and how bad mistakes trickle back to the end of the traffic.
Don't worry too much about it - unless you ban all existing cars, we're stuck with the mixed traffic for the foreseeable future. Once you're 100% robotic, you could just use smaller cars to get more effective lanes instead of increasing speeds.
Not that you could increase speeds safely - SDCs still need to brake in time, and they're bound by the same laws of physics, and there are still blind corners in the future.
Indeed. I think the future of self driving cars will be as a last-mile service for public transport. This will likely improve ridership, both due to the convenience of door-to-door transport, and also by allowing stations to serve much larger areas effectively. It also means the cars themselves can be much more efficient, as they only need to travel short distances, and usually only need to carry one person.
And, yet, most high density cities also have a huge amount of automobile traffic in addition to whatever public transportation they have. (Although, depending upon the city, a significant portion of that auto traffic is cabs--in part because of the expense/difficulty of parking.)
I am not sure self-driving cars will reduce traffic. My expectation is that they will increase traffic. By a lot probably. And commutes will get even longer.
You're assuming car ownership will remain in place as it is now. If vehicles are shared instead of fully owned, you can be more efficient. Think of how many trips are simply transporting a car. For example, let's say I need to pick up a friend from the airport. I would waste a one-way trip going to the airport. I didn't need to go to the airport. The only reason it was necessary for me to go is that I needed to get a car to my friend.
If my fried could have just summoned the nearest self driving car, an entire one way trip wouldn't ever occurred.
If it becomes popular to share cars then this may work. Looking at reality I have my doubts though. If people wanted to share cars you would see neighbors sharing cars for example. In the US many families or friends not even share cars. When I go out with people it ends up with seven people going in 4 cars or similar.
A self driving car takes the pain out of driving so unless society changes a lot we will see more cars driving around (often empty) and people will have longer commutes while sleeping their car.
Sharing a vehicle is not fun when the other driver could: 1. wreck it, 2. not return it promptly, 3. trash it. A self-driving car solves problem 1, partially solves 2, and does nothing for 3.
Put together a amalgam self-driving Sanisette [1] and you implement an even more ridiculous aspect of Idiocracy than its La-Z-Boy with a built-in toilet [2]. And while I make a joke about it now, someones in the future are going to convince a line of VCs to incrementally enable people eventually gaming/Facebooking in VR while hurtling down the freeway doing Number Two, and get handsome exits on each step towards that, and it will all be counted as a net economic benefit in the end. I'm either kidding, or will have checked out well before that ever becomes mainstream.
I think that self driving cars will help with parking, but not with traffic. You won't have to park your car in the city, where space is at a premium, the car will go park itself at another location, or pick up another passenger.
I think self-driving cars will reduce congestion in two ways. On freeways, due to slow human reaction times, there is a 2 car-length space between cars, meaning cars only take up about a third of the space on the freeway. With self-driving cars, there is near instant reaction time, so the space between cars will be 2 feet. With that, you basically triple the amount of cars on the freeway, reducing congestion by two-thirds.
In addition to this, on surface streets, traffic lights meter traffic through intersections. With self-driving cars, the cars will be able to go through intersections without the need for a traffic light, eliminating that metering effect.
Highly unlikely. We'll probably be able to get twice the usage out of existing roads because the distance between cars will shrink dramatically.
In my cynical opinion SDCs will likely precipitate a ten year pause in new road construction as drive times drop dramatically. But at some point we'll catch up to the additional capacity and spend another five or six years suffering as roads are built and expanded.
But the newly constructed roads will be more efficiently utilized than roads at present, so it will be cheaper per passenger mile.
