Push and Pull Factors and Measuring Modal Shift
There’s a longstanding debate among activists and academics about what the best way of effecting modal shift from cars to public transport is. Pull factors concern making public transport better through building more rail lines, running them more frequently, improving service convenience, or reducing fares. Push factors concern making driving harder through speed limits, fuel taxes, congestion pricing, and reallocation of street space from cars to public and non-motorized transport. There’s a tendency on the New Left to favor push factors (but the East Asian developmental states are best characterized as push-before-pull and not pure pull).
This has been refined by researchers at the climate research institute, the Ariadne Project, who published a paper in late 2021 rating various push and pull policies on effectiveness for reducing transport emissions. They conclude that push factors dominate, and pull factors are small, with construction of new public transit almost insignificant, only worth a reduction of around 300,000 tons of CO2 a year Germany-wide, 0.039% of national emissions as of 2021; instituting a 120 km/h speed limit on the Autobahn is said to have about 10 times that effect, while the biggest effects yet would come from carbon taxes. The study laments that pull factors are so much more popular than push factors, which they admit suppress society-wide consumption.
The research suffers from the same problem as other work in this direction, in that it is bad at estimating the impact of public transport on mode shift. It briefly argues that construction of public transport increases overall consumption and therefore doesn’t do much to reduce emissions. This way, it’s like 2020’s carbon critique of U-Bahn expansion, which I criticized two months ago; the carbon critique argues that each kilometer of U-Bahn built only reduces CO2 emissions by 714 tons a year through mode shift, under the assumption that only 20% of public transport riders are diverted from cars.
This doesn’t pass a sanity check. 300,000 divided by 714 is 420 km, which is about comparable to the total route length of the four grade-separated U-Bahn systems in Germany plus the Wuppertal Schwebebahn; I think the two figures, 300,000 and 714/km, come from different sources, and judging by the other elements in the study, I suspect 300,000 assumes less construction than a full doubling of Germany’s rapid transit network length. Nonetheless, even under a more generous assumption, this is far too low compared with macro trends in public transport usage.
The best way to use macro trends as a sanity check is to look at some cases with much more and much less public transport than the present. Do they look like it’s a total difference of 0.039%? No, and that’s even taking into account that transit cities tend to be wealthier, stimulating more consumption and more production. As I pointed out in my post two months ago, while Germany averages 9.15 t-CO2/capita, Berlin only does 5.38, and while Germany averages 580 cars per 1,000 people, Berlin only does 327. The difference is largely about Berlin’s pull factors. Push factors in the city are not extensive, and what exists is implemented only in areas that already have very low car use.
Even lower household emissions in Berlin must be viewed as downstream of the density that is enabled by the presence of a large urban rail network. Cars are a low-capacity mode of transport, so an auto-oriented region, like American metro regions, has to spread out its homes and destinations to limit congestion, and this increases household emissions (single-family houses emit more than apartment buildings) and also encourages people to travel longer distances for their commute and routine non-commute trips.
This is not easy to measure. Public transport projects have gotten fairly good in the last generation at estimating ridership, but estimating the responsibility of one particular project to modal shift is hard. It interacts with the entire city region. For example, building one rail line can be measured to shift modes in the neighborhoods it serves, but it also encourages destinations to locate in city center since people from the neighborhoods the line serves can now access it, and the increase in office, retail, and community development then leads to a small modal shift citywide. Worse, trying to tease out the effect of the rail line on modal shift sufficiently carefully may lead researchers to count this citywide effect negatively, since one econometric technique is to compare the neighborhoods near the line with neighborhoods in the same city not on the line.
In practice, the construction of rail lines tends to co-occur with other policies that improve public transport, which may be pull or push factors. This means that it’s very easy to misattribute the effect of urban rail expansion to those other factors. I am convinced that this is what is happening here; the proper comparison must be at the level of an entire region, looking at the emissions of different regions with different levels of public transport usage.
The upshot is that if it is hard to measure the effect of public transport construction on modal shift and emissions, then the uncertain factors should not be set to zero. Rather, they should be set to sanity-check levels. For example, one can compare New York with the rest of the United States, since it’s a starker difference between a transit city and an auto-oriented country than anywhere in Europe, and correct for non-transport effects like climate and electricity mix, both of which are easy to measure.
Within Germany, Berlin has 42% lower emissions than the rest of the country per capita. Berlin achieves this with an urban rail network that, in 2019, got 1,289 million rail trips, nearly all within the city of 3.7 million, a minority in the suburban region of perhaps 1.3 million. This is around 250 trips/person regionwide, and 320/person citywide assigning around 20% of S-Bahn ridership to suburbs like Potsdam and Oranienburg. What’s more, Germany doesn’t start from zero; this is not the United States, with multiple large cities with around 10 annual rail trips per capita. Netting out buses from VDV’s data (p. 25) gets around 6.3 billion rail trips in Germany in 2019 including trams, or 75 per capita.
The difference between 320 and 75 is around 250 – I know it’s actually 245 but at this point I’m deliberately reducing precision because those are sanity-check estimates and I don’t want people thinking they’re correct to three significant figures (try 1.5). If we attribute the entire Berlin-Germany difference of about 3.8 t-CO2/capita to public transport and downstream changes to the urban layout, then we get 0.015 t saved per annual trip generated. To get from there to 300,000 tons saved, we just need 20 million annual rail riders, or around 65,000 daily ones, which is easy to generate on a single line; the approximately 2 km extension of U8 to Märkisches Viertel that Berlin keeps postponing is estimated to generate 25,000-30,000.
Now, to sanity-check the sanity check, the estimate here is that every trip on urban rail saves 15 kg-CO2. This is an aggressive figure; new cars nowadays average 100 g/km and averaged 180 g/km in 2001 (source, PDF-p. 15), and the average displaced car trip is not 150 km or even 80 km – Americans average around 45 km/day, or somewhat more when only adults are considered. Rather, the issue is a combination of factors:
- Because the limiting factor to car transport is capacity, in practice what happens in an auto-oriented region is that it fills from the inside outward, and any modal shift ends up displacing the outermost and longest car trips. I proposed a model for that in a blog post from four years ago.
- Public transport displaces car trips on a more than one-to-one basis (and certainly more than 20% as in the carbon critique of the U-Bahn). This is because public transport users also walk and bike, and transit cities have high modal splits for active transport by the standards of auto-oriented cities, if not by the standards of Dutch cities. Berlin’s all-trip modal split in 2018 was 26% car, 27% public transport, 18% bike, 30% walking – and the high active transport modal split exists not because of road diets, which are few and far between, but because of the presence of a large core fed by the U- and S-Bahn.
- Public transport reduces household energy usage by encouraging people to live in apartment buildings with shared walls rather than in single-family houses, which have much greater heating requirements; this is also the mechanism through which transit cities have relatively high usage of active transport even without trying very hard.
I don’t think these factors fully explain away the gap between 45 km/day and 150 km per trip (so around 300/day), but they explain a large enough fraction of it that the installation of a system like what Berlin has – or, better, what Tokyo has – should be a climate priority. If your model says it doesn’t, it needs a lot more work than to just talk about the consumption effects of more public transport (if you’re bothered by how Berlin is poor for its size, compare New York with the rest of the United States).
In fact, if estimating modal shift is hard, then it’s best to approximate it by ridership. It’s imperfect because there is the effect of walking and biking; some lines really do just compete with walking, like city-center streetcars, but usually, to first order, it’s a good enough estimate. If it’s hard to estimate the benefits then they should not be set to zero, but rather set proportionally to something easier to measure, in this case ridership. Investment should follow ridership-maximizing strategies, and only deviate from them in corner cases.
Pedestrian Observations 
I would have thought in Berlin push factors would be the dominant reason for its modal split. When compared to, say, Wolfsburg, it is just a lot harder to own a car, particularly in the inner areas, primarily due to the lack of parking in residential areas (this is also what makes these areas so pleasant to live in).
And those areas were primarily built out before the development of the U-Bahn and S-Bahn, when trams were the dominant mode of mechanised transport. There are also obvious historical specificities about Berlin: one half of the city did not experience the US-imported mania for car travel of the post-war period, and the other half literally had a wall around it, so sprawl never really happened.
I’m not saying this is a reason not to build U-Bahn lines, things like the Märkisches Viertel extension are obviously needed. Just that the data might not really support your argument as much as you think they do.
The better comparison would be two similarly sized, similarly wealthy cities, one of which has embarked on a recent program of expanding transit, and the other which hasn’t. You probably won’t find that within Germany, where policy differences aren’t that stark. But maybe something like Vancouver vs Austin would work
The Wilhelmine Ring predates the U-Bahn, sure. But.
1. Most of the city lives outside the Ring, with lots of 20c TOD.
2. In situations without public transport, like many older US cities, the old streetcar-oriented neighborhoods were demolished.
3. The push factors in Berlin are a natural outgrowth of having a lot of people in one place; parking policy is not run by the Green Party but by asshole judges who strike down pedestrian and bike project as illegal restraints on mobility rights for cars.
Cold War West Berlin had a wall limiting its ability to sprawl infinitely, but it still built A100 for urban driving, and had plenty of low-density suburban neighborhoods and not just Wannsee.
Vancouver is not the cleanest comparison to US cases, because of issues of climate and electricity mix; those can be controlled relatively easily, but then the issue of energy efficiency is harder to see because of how clean British Columbia’s electricity is.
Yeah, I don’t see the counterfactual where Berlin never builds an U-Bahn or S-Bahn and retains its high inner city density and non-car modal share. Is there any Berlin-sized city in the developed world with such a low car share and where trams are the fastest transit option?
Well East Berlin never built as much U-Bahn as West Berlin, and a big chunk of it (the arc between the U2 and the U5) is primarily dependent on trams for radial journeys. It doesn’t seem to have any worse of a mode share as the more U-Bahn heavy West (although that would require a fine-grained study to demonstrate).
And Zürich famously has attained a very high mode share by concentrating on improving its tram and S-Bahn network rather than building new U-Bahn lines.
Of course, trams have an innate limit to what they can achieve, since beyond about 10km from the city centre they become intolerably slow.
But then my argument wasn’t that cities don’t need to build U-Bahn lines, it was that Berlin’s low car usage is primarily a result of the car-hostile urban form of its inner districts (Blockrandbebauung), and this predates its adoption of mass transit. Krumme Lanke has an U-Bahn line running to it and Bötzowviertel doesn’t, but I’m going to hazard a guess that Bötzowviertel has much lower car usage. The residents of the former might use the U-Bahn for trips to the city centre, but they’ll use a car for everything else. Whereas most people in Bötzowviertel wouldn’t even have a car in the first place.
I don’t get your point about Zurich. S-Bahn is still rapid transit, and Zurich has probably the most S-Bahn infrastructure for a city of its size. Can’t accuse it of investing little in rapid transit.
Yeah but the point is that these car-hostile urban cores can hollow out. Until recently the tendency in a lot of cities has been to lose residents in favour of the suburbs. If you want to stem the tide, and if you want to make sure that the growing suburbs are transit-oriented, you need to invest in rapid transit.
Not just can; did. East Berlin didn’t really renovate old buildings, so Prenzlauer Berg’s housing quality was bad at unification, and it took a lot of unification-related investment to bring it up to par. Does this happen without the transit city core? Maybe, maybe not; this is the 1990s and by then it’s clear that city centers are desirable and wholesale demolitions are bad, but then look at what’s happening to transit and car use in smaller Eastern European cities that don’t have strong transit-oriented cores.
How about Dallas and Houston? Dallas has invested in a massive transit network which gets little ridership. Houston has a more minimal transit network but a lower carbon footprint, presumably because it has more infill housing development.
Houston and Dallas both have about 0% transit modal splits. I suspect any difference in carbon footprint would come from non-transportation factors like electricity requirements (Dallas has both hotter summers and colder winters).
The very fact that Dallas’s big transit network hasn’t raised its modal split above “about 0%” says a lot about pull factors.
I guess it is true that Dallas has more extreme weather than Houston (being further from the coast), but at least as of 2010, Houston was denser and the density gap was growing (despite Dallas having a bigger transit network), which affects carbon footprint through both transportation paths (shorter trips needed) and non-transportation paths (less HVAC needed).
Right, I’m not claiming that building transit alone is enough to reduce emissions; I’m claiming that building transit that people ride is, hence the connection between ridership and emissions.
I’m totally on board with ridership as a metric, but what fraction of emissions comes from places where current conditions allow pull factors to work, versus places where the only way to generate ridership would be to interrupt an already self-sustaining auto-oriented system?
In Germany? Fairly high, we don’t have Atlantas. But in the US, I suspect that the topline figure connecting transit ridership with reduced emissions is even sharper, because American drivers drive longer distances and have bigger cars and less energy-efficient homes. The issue in the US is that it’s harder to generate transit ridership in the long run because of the land use issues you mention, but conversely there’s a massive number of low-hanging fruit, plus a bunch of really rich cities with transit cores that are crying for higher-density rezoning.
Don’t forget that the most efficient ways of heating homes – district heating and ground source heat pumps – also have agglomeration benefits.
It’s much easier to district heat a denser area than one of spread-out ‘burbs. To say nothing of the easier opt-in process if all units are owned by the same entity (whether state or private).
Of course nuclear district heating has thus far been implemented far too little, but it *has* been implemented and notably in planned economies which can take a 10’000 ft “overall” view of efficiency often absent in non-planned systems…
Central heating is a solved problem. It’s up to the government to implement the solutions.
A more important problem in the future is central cooling. Historically, only two developed cities would have such a need (Hong Kong and Singapore) but neither city developed a solution. But in light of global warming, more heat waves will be hitting Europe and other traditionally cold places. These heat waves can kill people without good access to water or cooling.
And due to physics, cooling is more energy intensive than heating. Therefore, a central cooling system will be even more energy-saving.
The problem with central cooling is that basically no industrial processes produce significant waste cold.
In addition, absent reuse of industrial waste, air conditioning is way more efficient than heating. Heat pumps are the most efficient way to heat or cool a room, if you need to produce the hot or cold yourself. Heat pump installations tend to be more efficient at cooling than heating.
Heat pumps don’t get significantly more efficient as they get larger, so sharing one between many buildings, or even between many tenants in one building is not useful.
Also, as more industrial waste heat sources are replaced by new green technologies that don’t produce significant waste heat, a lot of central district heating neighborhoods will have to switch to heat pumps for heating as well.
Cold can be readily generated from waste steam. In fact, early ACs are powered by steam, and that’s why the electric locomotive GG-1 had an onboard steam boiler.
Interestingly, one city implemented a solution in the seventies, behind the Iron Curtain. Even more interestingly, the local university claims that “one of the oldest district cooling systems in Europe” was built there in 1973.
They were using waste heat from the local coal power plant for the cold, as they didn’t need much heating in the winter. (Note that Chemnitz was known as Karl-Marx-Stadt at that time.)
The “opt”-in process can be even easier if you have mandatory-in like the German Anschlusszwang. Now even possible for generalized ‘climate protection’ reasons in addition to specific, localized air quality reasons.
The Chiltern lines growth from ~0 in the 1980s to ~30m riders a year pre-Covid is pretty much all pull.
It’s all down to increasing line speeds to 160km/h with all trains doing 120km/h and adding parkway stations.
One thing that should also be considered is the effect of pull factors on the political feasability of pull factors. I would expect that making car use more difficult will be far more politically unpopular if there are no good alternatives than if there are.
Yes, and the study mentions this: it even looks at polling for the various measures, and laments how pull factors are more popular than push factors (never mind that the most significant push factor, the carbon tax, is happening to an extent and contra the poll showing it’s unpopular, it got through the GroKo and CDU isn’t currently running against it).
I feel like these people might as well prefer a bus every hour instead of every 10 minutes because frequent bus consume more fuel and emit more co2 as a result
The carbon critics tend to mostly fight U-Bahn expansion due to embedded carbon, not bus frequency. These people tend to live in city centers and near-center neighborhoods served by trams, so neither subways nor buses are terribly relevant to them.
The people who fight transit expansions because of carbon footprints are like the green advocates who don’t realize that dense cities are better for the environment because you have more people occupying less space, leaving more room for nature.
There’s a mistaken idea that if you stop both road and transit mega projects, modal shares will remain stable. But actually in such a situation car mode share keeps going up. On autopilot, local government can keep building/upgrading smaller roads. If no new transport capacity is built in urban cores, then housing and stores and offices will be built in sprawly suburbs instead, served by those smaller roads that we can keep building year after year.
Build rapid transit, and growth can happen both in the urban core and in railway suburbs, which are “naturally” unfriendly places for cars.
The location of development doesn’t mechanically follow the location of transportation investment – it happens wherever market demand exceeds the cost of construction, and the legal regime permits construction. Very often market demand is strongest in the core, but legal restrictions prevent construction there. Remove those restrictions, and future development will be concentrated on the core and non-car modeshare may even improve despite a lack of investment in transit. Keep the restrictions, and there will be no development in the core no matter how generous your transit investment.
Maybe regulation is the limit on core growth, but the character of suburban development absolutely depends on transit investment. Maybe core Paris will never grow as long as the current planning regime stays in place, but its nice that their suburbs are TOD rather than the awful Côte d’Azur sprawl.
But let me note that even in a regulation-constrained urban core like Paris, job growth can still happen by converting housing to commercial uses. And job concentration is more important than housing concentration.
Yeah, that’s the situation in Los Angeles, essentially. Its last new freeway, the Century Freeway, opened in 1993, at very high cost caused by a combination of poor design (they didn’t properly survey the geology) and freeway revolts and lawsuits (the Green Line in the median is a mitigation extracted by the revolters). It’s widened a few other freeways since but nothing on the scale of Texas, just one extra lane here and there. And there’s still adverse modal shift as the remains of the people who are too poor to afford a car become rich enough to afford one and as the state has permitted illegal immigrants to get licenses.
Also single car households becoming two car households. In working class suburban Europe I believe one car is still the standard, but it’s changing as people get richer.
My general feeling is that even with heavy traffic and governments making cars hard to use, the car is still going to beat out transit because of the prestige of driving and also the fact that you are in your own little space and can listen to the music you want, etc. rather than having to deal with hundreds of thousands of other people on transit. Even if people behave themselves, many people do not like transit for the crush factor. There is also the last mile problem, which is something a lot of people complain about rather than dealing with a short walk to the station. Therefore, you really need to push people out of their cars and that might not even work out that well because lots of people seem to prefer sitting in traffic in their own car to going fast on transit. I know people who don’t own cars but still prefer using rideshares rather than transit to get places even though they live in San Francisco.
What is heavy traffic but “having to deal with hundreds of thousands of other people”? (If anything, you tend to interact with a lot *more* people, and a lot more interactively, on a typical highway commute than in navigating a train station and train car or two.) Our societies have just normalized the one that involves cars, while stigmatizing the other.
I’m not saying you’re wrong about current public psychology, just that I don’t think this is insurmountable if people get actual experience of well-maintained, sufficiently frequent rapid transit options that have the resources not to be hugely overcrowded.
The difference between heavy traffic and transit is that the interactions with other people are seen as more indirect in traffic unless you get into an accident. You might be frustrated from all the sitting around or the slow pace but you are in your car, listening to what you want to listen to, and don’t have to deal directly with obnoxious behavior. I think most people seeing stuffed in train or bus or and potentially having to deal with the more unruly and unpleasant transit users is a much more horrible experience even if they are on transit for a shorter amount of time. At least in North America, I think the big problem comes with policing behavior on transit. While most rides are without incident, you just need one person who is having a loud drag out argument or is blasting music on a portable speaker or is using drugs, and I’ve encountered all three, or some other anti-social behavior to make the ride not fun even if short.
There are asshole drivers who threaten to hit you with their big cars, often specially modified to be more threatening (noisier, taller, etc.).
I agree that there are asshole drivers and these asshole drivers can do real damage. The difference psychologically is that people dealing with asshole drivers in their own car see their car as armor. When having to deal with asshole transit users, people feel much more unprotected psychologically. Most people would fear more exposed to harm.
Asshole transit users are extremely rare in my experience, people on transit generally just want to get to work or whatever. Crush loaded transit is annoying, but not a case of assholeness. (Maybe things are different for women.)
In contrast, on nearly every road trip you will see someone near you doing something dangerous.
The most dangerous (and dangerous-feeling, which is not the same but also matters) part of my transit trip is crossing a road to get to/from the stop.
The whole reason for the SUV arms race is that many drivers *don’t* feel safe in their cars and they want a bigger one to protect themselves against others driving SUVs.
And that’s not just me guessing, people tell me that.
Eric2, I agree that asshole transit users are very rare, although they seem more common on the West Coast than East Coast for some reason in my experience, and yes transit users are still going to use transit. But most regular transit users have basically immunized themselves to the occasional asshole. For non-transit users, the situation can be scary. I’ve also had many women tell me that they feel unsafe on transit alone even though they know the statistical chances of something bad happening to them are slim.
Diego, I always saw the SUV arms race about status seeking and chest thumping more than anything else. That and people say they need SUVs to hall their kids and stuff around even though people are having fewer kids to haul around.
Women ride transit massively more than men do – I keep seeing it in a variety of countries, but it looks like something like 55-60% of transit users are women, and the skew is especially large for non-work trips (in the US, 50% of transit commuters and 55% of transit users are women).
There are real issues of safety, but they’re much more about boring transit usability like bus shelter and good lighting than about tabloid media headlines about crime.
Fair, a lot of SUV buying is about status games. I’ve heard stories of people getting really upset when a more junior colleague drives a fancier car than them.
But I’ve had family/colleagues tell me directly they feel safer in a SUV, not so small and vulnerable compared to other cars.
When 90+% of the population is driving, it’s a fair bet that a lot of them do it out of necessity and aren’t very happy with it. They’d welcome alternatives, even if those have their own trade offs.
Nobody wants to ride a crushy train. But when trains became excessively crushy, Tokyo people rioted against railroad operators instead of wallking into their “own little spaces”. https://ja.wikipedia.org/wiki/%E9%A6%96%E9%83%BD%E5%9C%8F%E5%9B%BD%E9%9B%BB%E6%9A%B4%E5%8B%95
An outburst induced by strike action amid the heated labour politics of 1970s JNR isn’t the best example of passenger backlash to crush loads. By the time of the 1973 riots, average crowding levels on Tokyo area train services was well below what they had been during the 60s.
I do not read Japanese but John D does point this occurred during the 1970s. Even though this was well into the post-war recovery and boom, I’d imagine that car ownership was still rather rare in Japan even among the middle classes. Americans were very quick adaptors to the car and were basically abandoning transit in many places by the 1920s in favor of driving everywhere. The places that had transit in the US at this point just dealt with the conditions on it.
re. Japan- car ownership hovered just above 20% in 1970 for single family households, it rose to 40% in 1975. It’s now about 81%.
Japanese car ownership being still below 50% in the mid-1970s explains why people who heavily protest bad transit practices. In contrast the United States had mass car ownership among just about every group including African-Americans before World War II and definitely shortly afterwards. The Green Book was written for African-American car drivers not train or bus riders. The Soviet Union allowed good times to be aired on Soviet TV because they believed it would show the rottenness of the American system but the average Soviet citizen was floored that even working class African-Americans could afford cars while they had a ten year wait for one.
Do you have some evidence of mass car ownership among African Americans in the postwar period? It seems doubtful to me at first glance. A major component of the 1950s-1960s Civil Rights movement was focused on integration of public transit; the significance (both historic and economic) of the Montgomery Bus Boycott, for instance, would not make sense if most African Americans had been driving everywhere.
The closest I found was this 2020 Smithsonian article that estimates 475,000 African-American families owned at least one car by the 1950s.
https://www.smithsonianmag.com/history/how-automobiles-helped-power-civil-rights-movement-180974300/
Another article not linked estimated that 21% of African-Americans took transit or walked to work in 2001.
A google search reveals that 475,000 African-American families are estimated to be owning at least one car by the 1950s.
…. there were enough of them to have a travel guide…..
Is “New Left” a term used by urbanists to describe resurgent left-ish flavour in the current political moment? Because to my knowledge it specifically refers to the New Left movement from the 1960s and 1970s.
I mean the movement from the 1960s and 70s and its aftermath. The Death and Life is from the 1960s, and the Dutch bike revolution began in the 1970s.
Another thing that the study misses is that getting political support for push factors often requires pull factors to exist. It’s likely easier to get support for parking maximums, congestion pricing, and other anti-car policies in regions like NYC, where most commuters in the city proper take the train, than in LA, where almost everyone drives. If NY implements its congestion pricing plan, the Ariadne movement wouldn’t give any credit to the subway system for the congestion pricing plan’s success, but I doubt such a plan would get implemented in a transit-free city.
If transit isn’t a reasonable option then push factors will get you voted out of office and the push factors removed. Where transit is a reasonable option you can get some success with push factors because people who just “never got around to trying transit” get annoyed enough and discover transit isn’t as bad/hard/dangerous/slow/whatever as they thought.
Most people in North America do not have a reasonable transit option if they got the idea to try it. When the bus comes every half hour that is not reasonable. When the walk to the bus stop is several miles that isn’t reasonable (you can drive to a park and ride, but then why not drive the rest of the way?). When a 10 minute trip by car requires you to ride the bus for 45 minutes, then transfer, then 45 minutes back out – that isn’t reasonable. The above are all situations I’ve personally faced trying to use transit in my life. I did ride the every half hour bus, but i hate driving if you don’t share that hate the bus service was not reasonable, and it showed by the other people who rode the bus (kids going to school, or adults who were clearly poor or had obvious ‘issues’)
The first step has to be building a decent transit system and running it at high frequencies, something that transit advocates, fans, and users know needs to be done but the civil servants running the system seem scared to do. So you need to have trains and buses come with low headways even if practically nobody is using them. Then when you get transit to a good enough level, you have to use pull and push factors to get people to use it.
I think the low level civil servants running the systems know that. I know that at least some of the big consultants the high levels hire know that. There is evidence that the high level leaders do not know that (even when the hire good consultants).
It doesn’t matter though as running good service is expensive and so it is really hard to find the money. Even places where good service would pay for itself in fares alone often can’t get good enough service because you have to invest in good service for a few years before people respond. Not to mention when you do get riders their fares are often used to subsidize routes that will never pay for themselves (we can debate if such routes are worth it because of network effects, or to serve some population)
There is a credibility problem that transit in the US needs to overcome. The cost estimates used to justify East Side Access, BART to SFO, California High Speed Rail, etc. fail spectacularly. The ridership estimates many times are equally bad (BART to SFO ….). Cost estimates for road construction don’t seem to blow up the same way, and usage of the roads is obvious to the casual observer.
On average, American cost and ridership estimates have been accurate for 20-25 years (link). Usually they’re a bit too pessimistic, and then from time to time (like BART to SFO) they’re widely optimistic, but on average it balances out. Very recently, paranoia about cost overruns has led to excessive contingencies, which guarantee high absolute costs, and still don’t solve the problem of occasional overruns for tunneled projects like ESA.
Cost estimates for roads absolutely go up too – the Big Dig is infamous for this, as is the Alaskan Way Viaduct. The Interstate system overall ran over by a factor of about 2.5 in real terms.