Shouldn't we be switching buses with light railway?

Light rail/trams are better especially for avenues etc. But busses are more flexible, and you usually need a combination of both for best results

This.

I think of buses as the caterpillar to a tram's butterfly.

You can start with a comprehensive bus network, and as a particular route stabilizes and the bus starts struggling to meet throughput needs, that is an indicator that a tram may be worthwhile.

Starting w/ a tram line is a pretty big financial bet that it will be useful/needed, as once you build it, you're locked-in to that specific route.
Buses for longer journeys make sense. We have a bunch of buses in London that run from the city centre out towards the green belt. Buses for those especially long journeys makes sense.
- Why not just build a train for long journies? Cheaper over time, more capacity, and reduces road dependency.
- Buses are awful for long journeys. Trams for longer journeys make sense. You need the buses to get you to the tram stop.

The big benefit of light rail is you can make trains longer than buses, and fit more people. So if your system has outgrown buses, then you should move to rail.

But transit systems should always be trying to maximize frequency, because the more frequently a train or bus comes, the more convenient it is for riders. So if a bus fits 30 people and a train fits 90 and you’re trying to make a decision between providing a bus service every 10 minutes or a train service every 30 minutes, the bus service is the better option.

Different modes work best for different passenger demands, and you should use the right one for the number of passengers you’ve got. Overbuilding is expensive, and if you spend too much building out a network and the don’t have enough for operating expenses then you’ve got to reduce service levels.

Most tram systems aim for 5 - 7.5 minute frequency on trunk lines during peak hours. Usually induced demand works here if it's more convenient than sitting in a car. Busses quite often are a little unreliable when it comes to any kind of attempts to schedule even with dedicated lanes, since they spend more time at the stops loading and unloading passengers and you need more of them compared to trams. Then there's an argument to be made about public mass transportation: It should provide a service that is good for the city and the people and in a well designed system subsidies aren't going to waste even if you're unable to measure any profit. Ridership and travel patterns matter the most. Not all rail is equal either. The available options are from cheap (which is not same as bad) to expensive: from tram systems on street level to "heavy" rail in tunnels. The tram is very versatile and often the most affordable way of providing reliable service when combined with busses on lines where the demand is really low. If you need a bus more often than once every ten minutes and/or they're packed to the brim during rush hours you probably should think about ditching the fears of "overbuilding" and start planning for more capacity and frequency with a tram line. In your country this might be different but in most developed countries the drivers are not unsignificant expense and trams reduce the amount of drivers needed, they have lower power consumption compared to buses and are mostly more reliable than buses. Also the ridership usually prefer a tram if the option is provided and it's not super slow (which is rare). Then again, if it's built in the right place -> induced demand.

There's pros and cons of buses vs trams.

The pros that I'd slate for trams do include a better ride, more throughput (carries more people), wholly electric, are more durable than busses, and very quiet in general. People in this thread have noted most of these already, but the one that I feel is very overlooked is that they're a commitment by the city along their routes. Many people will note that busses have advantages because their routes are easier to change. While true, I feel it's actually worth considering that this is also a negative from the perspective of anyone who wants to invest in property that relies upon the bus route. If you can't trust that the city won't just up and move the bus stop away from your shop or apartment complex, you'll be more reluctant to invest in the location. Trams are indeed much harder to change, but that's actually a good thing from the perspective of investors. If I'm going to invest millions of dollars in an apartment complex, would I rather do it next to a bus stop that might not be there next year, or a tram stop that's really hard to move away?

Another advantage is how well the tram integrates with pedestrians. Busses are only as accurate as the driver. As a pedestrian, I have to pay attention to every bus just as I would cars on the road. They're dangerous to be around. Trams are much more predictable (see: rails) so they can be used in/around public squares, markets, and along walkways with more safety for the people walking nearby. The rails themselves also show you where the transit is. Bus routes are invisible except for the stops and when you see the busses go by. When I'm walking in a city that has railed transit, I love seeing the rails because I know that I likely follow them to the next stop, and that by stops there will be shops, stores, and interesting places. They're a guide to the best places in the city even if I can't see the tram at that exact moment.

Trams are also usually larger inside. There's more room for wheelchairs, bicycles, and other mobility aids. They're a better conveyance for people who need the room. Those same people also need to pick where they live carefully so that their transit won't up and change on them. Having the bus stop move a block away could be a huge hurdle for their daily mobility needs.

Railed transit provides a permanency and a more equitable transit solution for a city. It's not the right solution in every instance, but as a city grows it needs to start investing in railed transit. Those rails provide the bones of where growth will centralize around giving the city focus and then identity as neighborhoods grow around tram/light rail stops. There's a power to railed transit that busses just don't provide in their stability, visibility, and statement of commitment to the longevity that a city should be investing in.

Also, look up grassy tram lines. That's peak urbanism!

I'd never heard of grassy tramlines, I love them! I've never seen any anywhere, and I've been all over Europe, they are either quite rare, or I haven't been paying attention.
- We've even got them in Finland and we only have two cities with a tram network. Otherwise I've seen them a lot in Germany and newer systems tend to have them more often than older ones.
- I'd seen quite a few pictures and video of them, but the first ones I actually got to walk around and ride on were in Heidelberg in Germany. The north lines (5, 21, 24, 26) have grassy tram sections.
- We have some small sections of grassy tram lines in Melbourne (Australia) but I wish we had more.
I mostly agree with you that trams are generally better, but we need to point out that bus stations are not placed randomly on the map. If an appartment complex gets build somewhere, a bus station will also appear next to it, probably faster than rail transport (assuming whichever organism in charge is competent, and that there is discussion between them and the users). Busses are better suited places with less trafic and fast to put in place. Trams are good long term and better for pedestrians. (and a lot cooler and more comforable)
It's also beneficial for users of the systems, most of which are non-investors, that the lines do not change ever so often and the stops don't vanish or move several hundred meters.
in kansas city they funded light rail with property taxes and the increase in property value offset the tax and then some

Light rail is infinitely more expensive to construct and it only takes one delay/accident and all subsequent trains after cause a log jam...vs a bus which can route around it.

A better solution uses corridors dedicated to buses that are electric powered.

Something like this was done in Colombia with these routes being connected by ground hubs, similar to subway stations.

That’s like saying a ship is more expensive than a car. It depends.

A tram is not „infinitely“ (what absurd statement is that anyway) more expensive than a bus.

Construction cost is not everything, and they’re not even that much higher, you also need to consider service life (much longer with trains), energy cost per passenger mile (much lower with trains thanks to the lower resistance), etc.

What is best is always depending on the specific circumstances.

The biggest limitation of buses is capacity, and a highly used tram is cheaper per passenger mile than a bus. Try replacing the S-Bahn in Berlin with BRT, see how far that gets you. You’d probably need to bulldoze a new highway… speaking of which:

Germany is actually hellbent on building a highway right through its capital Berlin, which currently clocks in at 700 milion € for 3.2 km. I expect the whole thing to end at ~2 bn € for ~7 km.

So I think the costs of public transport are really not the issue people should be focusing on.
- You wouldn't even have to go for the "replacing the S-Bahn" to show how ludicrous a BRT is as a suggestion, unless you're not paying the constructors and drivers a living wage, which is why it makes sense in say Colombia and not in Germany...just think about replacing the M-lines of Berlin tramways with a BRT. It would have to be couple meters wider, would be terribly unreliable and inefficient, not to speak of noisy and bumpy. Now who would want to have that? Not to mention how much the upkeep of two lanes of dedicated BRT costs vs. maintenance of steel on steel rails and catenary. (Most of the time you'd find the latter to be cheaper.) In Helsinki, Finland we are currently waiting for a new tram/light rail option to replace a bus service that should have been a modern tram/light rail line in the first place: https://raidejokeri.info/en/ In the neighbour municipality Vantaa some parties were trying to push for a BRT option but the independent research suggested light rail/tram option to be the best and this is what was chosen: https://www.vantaa.fi/en/housing-and-environment/traffic-and-transport/vantaa-light-rail (they call it light rail but in some ways it's also reasonable to call it a tram)
Electric busses are actually a lot more complex logistically than electric trains. With a train, you just need a bunch of big-ass transformers and overhead wires. Expensive to install, but very reliable and relatively low maintenance over many years.

Batteries on the other hand are heavy, relatively fragile, degrade quickly, and very expensive. With a 100KWh EV, about 1/3 of the total cost is the battery, so it would likewise increase the cost of a bus.

Charging is another problem, instead of the whole system using energy real-time, you now need a distribution system that can take hundreds of busses at night and charge them all back up, requiring a massive amount of power in a somewhat short time. While it’s nice that energy is generally cheaper at night, you still need the infrastructure that can take that load.

So, it’s not to say that there’s no place for them, just that our main focus needs to be on rail in most places. There are lots of low-density places with cheap power and temperate weather that absolutely need BEV busses, but a lot more with challenging weather, older grids, and medium density that are a better fit for rail.
- IMO electric busses needs to have a trolley bus infrastructure on some route so the bus is recharged during the day. Won’t cover 100% of the energy needs, but will spread out the charging time.
- Trolley buses do exist...
  
  https://en.m.wikipedia.org/wiki/Trolley_buses_in_Vancouver
- You can charge electric buses at termini though. Albeit this doesn't change the challenges much. The electric buses are best suited for lines where the higher capacity isn't needed and where the line is not likely to be longer than a little over 15 km.
Here in NYC, we switched to hybrid electric buses many years ago and are currently transitioning to all electric buses. I’m not sure about other cities.
Yes, we certainly can route around it, but having lived in London for most of my life, I can tell you that we seldom route around it. However given the capacity that light railway how. If we keep the vehicles moving on the main arteries, we can move more people alleviating the frustration.
This is a common misbelief. Trams and light rail usually have points where the units can go around if one unit has derailed, unless the unit has tipped over, which in itself is very very rare. Good planning is crucial. "A better solution uses corridors dedicated to buses that are electric powered." Nope, nope, nope. You have to present arguments to this claim, maybe then I can be bothered to counterargument such nonsense.
You have loops on the network for unidirectional or switches on strategic places to reverse in case of engineering works or incident.
Ah yes, and we can put those corridors underground in a big circle.

Like some kind of hyper-loop!

Probably biassed as I'm a bus driver but the city I'm in has a tram and it's fantastic until one gets blocked or broken. Benefit of busses is they can detour if needed, and if one breaks it doesn't (always) block the entire route

edit: extra annoying when they break down and I have to carry a tram load of passengers on one double decker bus

Biggest drawback for anything on rails really, it works either really well or not at all. I think it is still worth it, but I am also incredibly biased towards trains.
It's also very easy to reconfigure bus routes, just slap some new paint on the road.
- EV buses are not that easy to "configure" though

I usually prefer light railway too, because it usually is less impacted by traffic than buses (depends on the road structure, of course)

It’s less impacted by traffic only because it’s given priority.
- Sometimes light railway have their own lanes as well, physically split from the rest of traffic, which also helps

We tried in Denmark (Aarhus). Quite expensive, and too many issues. Electrical busses (with dedicated lanes) seems like the better solution, ~~bus~~ but this is also not cheap.

Edit: Spelling

But electrical buses still create an outrageous amount of rubber waste
- I've never heard rubber waste mentioned as an issue, what is that about?
- Don't let perfect be the enemy of good though, whatever increases ridership and gets people off cars faster is going to have a bigger impact on contamination.
Aarhus is not really a good example of replacing a bus, as it is a rather regional light rail system with a short inner city section. The difficulties they have seen are probably mainly caused by the technical and budgetary choices made during planning.

For Denmark, Odense looks like a better example, that should be successful if they manage to solve the initial challenges, e.g. with noise/vibrations.

As for the longevity that OP is mentioning, the systems in Bergen (Norway) and Tampere (Finland) show how important this is, with huge private investments being made along the lines. A bus line can be gone next year, but rails will stay for at least decades.
There's light rail in Odense too. And Copenhagen wants one as well...
I thought letbane was not bad. What issues are you referring to?

With the caveat that this only applies to my city, San Francisco... I prefer buses. SF horribly mismanages its "trams"* where they run at ground level through the streets. They must follow all stop signs and traffic rules. They don't even get signal priority. So it's a quite jarring experience to get into a train underground, exit the tunnel to the street, and begin stopping every block and waiting at red lights.

Fact of the matter is that, if you're going to be treated like a car, it's better to be more maneuverable as a bus. Buses can avoid double parked cars, and have a fighting chance of squeezing through a gridlocked intersection. With a bus lane, they can use it but they don't have to, where's trams are trapped in a traffic lane (frequently the centermost lane) while idiots make (frequently illegal) left turns.

* Muni light rail - K, J, L, M, N, T, F

This is the problem with all trams/streetcars, by definition they run at street level. If anything sf's are a bit better since they have underground sections. They don't have an advantage of speed, that can only be gained by getting right of way which is far more expensive and then it's not really a good comparison to a bus. The main advantage of trams are comfort, capacity and long term cost. Whether that trumps buses flexibility is up to debate.
- Street level is not the same thing as "among car traffic". For instance, there's a stretch of the N-Judah in SF between Embarcadero and 4th & King which is on street level, but in fact it is in an entirely separate right of way, where it is illegal for cars to drive. And unlike other places in SF where it's illegal for cars to be (like bike lanes, bus lanes, Market st), people actually respect that. So it's entirely possible to avoid the private car right of way. If you can avoid intermingling with cars, and you get signal priority, then you'll go faster than cars, because you're not stuck in traffic and you don't need to wait for the lights.
  
  The issue is that in this segment, I haven't noticed much in the way of signal priority. The N, which is far more important than any private car on those intersections, has to wait when it really should just sail through intersections, because the signals knew the N was coming and changed ahead of time.
  
  I know that this can be achieved more or less with BRT, but it seems absolutely silly to put in the rails without having a dedicated right of way, and yet that's what the majority of SF's above-ground light rail is. IMO, if there's light rail on the street, either it should be car free, or the railway should have curbs surrounding it to prevent intrusion from cars. Full stop.
While this is a point about implementation/regulation, and not about trams in general, it is an important point to make.

In my city of Hamburg, Germany, Iearned to avoid buses. Too often they get slowed down by traffic jams, which makes them late and unreliable.

Dedicated bus lanes, separated from cars, would solve the problem. Until they don't have that, the U-Bahn and S-Bahn (which run on rails separated from traffic, underground or above street level) are my clear favorites.

A city which prioritizes public transit, would/could give street level trams priority at traffic lights, and maybe even disallow cars from using the tracks as a normal lane.

Busses have their uses. Lots of commentor have mentioned the flexibility in setting up / changing routes. But there's also the flexibility in sizes. You can start a line with a large van or small mini bus and your only overhead is the driver. From there you can scale that up according to demand up to frequently run articulated busses. Meanwhile your minimum investment for tram includes at the very least a not inexpensive track installation.

Don't get me wrong. If you have the passenger volume that investment definitely pays off. But I don't like this unnecessary competition between two modes of transport that can be very complimentary to each other and are both better than individual cars.

It would mean that, for very high volume and consolidated bus routes where adding new busses would actually start to contribute to congestion, a city can then decide upon "upgrading" the entire line to a tram. Of course this means changing the infrastructure and lane structure on the involved streets and possibly the layout of the stations
I'm not suggesting light railway for new routes, but to replace the old routes that are fleshed out already.

Yes but it makes economic sense only on the routes with top demand that pass through the center or CBDs or other high traffic areas

When did we stop calling them trams?

Tramways and Light Rails are much more silent and comfortable. Rails are smooth, no pothole etc. They are also much much more durable than asphalt.

Rails take less space and can be covered with grass/greeneries. Looks prettier and absorb heat.

Tramways and Light Rails are much more silent

From inside, maybe? Berlin, where I live, has lots of trams all over the city. I admit I rarely use them as I much prefer my bicycle, but they are seriously noisy. During the day the noise is somewhat lost in the general cacophony of city life, but in the evenings you can hear them rattling and crashing along from streets away. And if you live on a road with a tramline, you just have to accept this horrible metal-on-metal screeching and rattling at almost all hours.

It's more reliable, usually runs on electric rather than buses, can run more frequent without causing congestion.

Only real con is that you need some time, money and maybe more space to add it

But isn't it a case that our governments keep pushing austerity and thus our infrastructure doesn't improve thus do things like run shitty services. The outlay is more expensive, but no one has ever said a light railway doesn't pay for itself.
- no one has ever said a light railway doesn't pay for itself.
  
  Most metro rail systems lose money. They cost more to operate than they generate in fare revenue.
  
  This is OK because they provide a useful public service and should be funded by tax dollars. Light rail should not be expected to turn a profit. It should be expected to benefit the community it serves, which it generally does.
- Yep, yet another reason for more light rail

The busiest core routes should be served with light rail, allowing an efficient high-frequency service for the most common journeys, and most parts of a city should ideally have some kind of connection to that rail system within a kilometre or two. But you can't just put rails and stations literally everywhere, so buses (or trolleybuses with batteries if you're so inclined) remain useful for less common routes, gaps between stations, the neighbouring areas of rail routes or last-mile connections from light rail to within a short walk of a person's final destination.

Buses are also necessary as a fallback during maintenance or unforeseen closures on the rail network. Even if it's just a temporary station closure, that one station will likely be the only one in walking distance for quite a few people (especially if we're talking about an interurban network where a small, outlying town or village might only have one station connecting it to the rest of its metro area), whereas that same area could have several bus stops, giving pretty much everyone there a way to continue getting around, perhaps even to get a bus to neighbouring stations.

And bus routes don't change that infrequently. Certainly, not infrequently enough that you'd want to tie them to placing or removing fixed infrastructure like tracks or wires. Diversions also happen sometimes. All of this isn't to argue against light rail, but to argue for a comprehensive multi-modal vision of public transport. Let passengers use the right combination of services for their particular journey's needs.

We have trams in the city where I work. Two problems have been: 1 cyclists having accidents when wheels get trapped in the tracks 2. Reliability problems because if a tram beaks down the whole line is interrupted.

Trams deserve to be separate from car and bike traffic: it allows trams to be faster than cars and it protects cyclists from falls. We need to stop thinking that cars should be everywhere by default.
- The roads are only 2 lanes wide in most part of this city, so you couldn’t really have separate lanes there (unless all the traffic only went one way). The tram goes in/out of the city from the suburbs on its own railway line in most parts, so that works well although it was slow and expensive to build. And in the city there are cycle-only lanes but cars and trams share the rest of the road.
  
  But cyclists would still be at risk, even with separate lanes. The two accidents (both a lot of skin grazing and one broken arm) that I know of were when cyclists have turned on/off the tram road to/from a side road and have gone over the track at a very acute angle. That said, both accidents happened just after the tram lines were built, so I think cyclists are able to avoid accidents but just need to be aware of how to cross the track safely. I have cycled there an it seemed pretty obvious how to cross, but clearly not so for everyone.
  
  The best solution would be to have electric buses, but I’ve never heard of them (except for the ones with overhead power that they had in the 1950s). Same environmental benefit as a tram but no tracks to trap cyclists. Routes can be changed, when needed, and breakdowns don’t stop the flow of other trams and cars.
  
  Oh, and two other problems with the tram system, at least in this city. 1 it’s funded by a ‘work place parking levy’, as well as the ticket price. So people who can’t use the tram to get to work and have subsidise people who do use the tram. That wasn’t well received. It also creates a lot of bureaucracy for employers who have become responsible for paying for it. The city council claimed that the tram system would still benefit motorists because there could be less traffic. This turned out not to be at all true. 2 And residents who were unhappy about having tram stations (raised roads, booths, lots of people, etc) built outside their homes were told by the council that they should be grateful because the transport convenience would add value to their homes.

Shouldn't we be switching buses with light railway?

Yes

But why put them on rails? As a kid I remember busses running on electricity from cables that were located above them. Isn't that the best of all versions?

Tyres wear down and produce nasty pollutants, and metal-on-metal is more energy efficient.
Trolley buses are good. But light railway lasts longer and does less damage to the road for vehicles that actually need to drive. Also you can go autonomous with light railway which is far easier on tracks than without.
Those are called trolley busses. They are pretty good, especially due newer ones that have batteries for any needed detours etc
They still have those buses in Dayton, Ohio.
Rail has some advantages. Efficiency, Tyre dust. Long term cost. It's a bit harder for the next government to dismantle it. Higher capacity, more predictable path/easier to give intersection priority. Much much easier to automate if given dedicated right of way. Better accessibility.

Rubber wheels have advantages too. Quieter, more flexible (especially with a buffer battery), lower per-vehicle cost can increase the number of services.

I think the first goal should be getting any service that doesn't get stuck in traffic. Then grade separation and consider the tradeoffs for rail.
Short answer: no.

Good luck climbing hills. Not saying it wasn't done before (I use a "tram" which does it daily), but it's one of the more expensive problems to solve.

San Fran managed.
- And Lisbon too, as a side bonus tourists love to see old trams going up the hill (in both cities).
- Not really. Unless you mean cable cars. But that's not really an alternate to a bus. Pretty sure they're way way way more expensive to maintain
- The cable cars are quite different from trams, they hook into a cable under the ground to get "dragged" along, they're not moving under their own power. Makes them quite expensive to construct and operate, and you can hear the cable noises a block away even when there's no cable car nearby.
  
  I mean they're also iconic and loads of fun to ride, but I think there's a reason people don't go installing new cable cars.
- They usually do it by tunneling through the hills to keep a lower grade ascent. Only the cable cars go up the really steep hills.

Trams are the cosiest things to sit in. I enjoy being half asleep in the morning and just look at all the people being busy. Wish my town had some more grassy lines, but they don't lack on where you can go.

(edit: I want to add that I am also happy with the buses here, don't think there is a reason to be either or and rather focus on reducing cars in town and in its suburbs. Obviously easier to do for smaller towns).

It depends on the type of light rail.

Here in my city the trams share some of the roads with regular traffic, which not only means they can get caught in traffic (though they have priority where possible), but it also means the rails become a real tripping hazard for cyclists (over 800 injuries since 2015 at the last count). There's been an active campaign to introduce more safety measures but the council has been reluctant to do anything about it.

The tramlines are such a well-known hazard to locals that they actually put people off from cycling, which is surely counter-productive.

Light rail transit has its own right of way. Sharing the road means it's a tram/streetcar.
- Yes, technically a tram at that point, though the system has sections of dedicated rights of way too, and has recently been expanded onto some old traditional rail lines in a tram/train hybrid system.
Are these the indented rails? Those will throw you off your bike instantly... Cycling lanes AND tramlines can coexist, but I guess the problem here is when you want to take a turn and the rails are in the middle of the road, so you're forced to just go over them? I guess they could implement some kind of underpass for cyclists and pedestrians.
- Having wider tyres ~2"/50mm or so pretty much eliminates the risk (and gives a comfy ride). If you really like the speed of narrow tyres, it's really quite safe with the right technique -- crossing tracks at an angle to avoid mishaps (I find 30° is sufficient, 90° is never a problem), and when they're slippery, treating them like ice. It becomes second nature soon enough.
  
  I think there are some rubber/elasromer inserts which have been developed which also eliminate the groove -- it presents a flat surface to bikes, yet squishes down for the tram wheel flange under the immense weight.
What kind of safety measures or adaptations exist currently to address an entire city’s infrastructure of tram/light rail lines?
Croydon?
- Sheffield. Though I imagine most modern UK tram systems are in a similar situation.

I'm surprised nobody pointed out that tyres are extremely polluting:
https://www.theguardian.com/environment/2022/jun/03/car-tyres-produce-more-particle-pollution-than-exhausts-tests-show

There is also another alternative: cable car. It's a good way to add public transportation with minimal impact on the existing road layout.

But doesn't have enough stops

It's not an either/or thing. Buses are great (if they are well funded) and light rail is also great

The problem with buses is that most of the fleets are still running on fossil fuels. Buses also produce a shocking amount of waste in used tires.
- Yes but depending on utilization and the size of the city they can have a much lesser impact compared to the creation of a light rail network.
exactly.

you can't assess the merits of an integrated transport system by arguing which one one mode of transport betters all others.

some places /routes (at some times) might work best with one option.
but most places / routes will be better served by several types at least at some times of day.

buses are one of the most flexible public transport options, fill gaps in space between high capacity modes, and fill gaps in timetables, and they sometimes fill gaps in affordability usually being cheaper.

give them bus lanes and priority at junctions, and they're a lot cheaper and more flexible than trams.

i always think that a busy packed bus lane is making the business case for a train, but filling the gap in the meanwhile. and sometimes a train is impractical.

they didn't only get rid of most of the trams in the uk due to cars wanting more roads. it was also because buses were cheaper and provided much better routes that could flex to travelers needs..

CityNerd posted a really good video on this topic a few months ago. https://youtu.be/H6UD9h3hEdk

His videos are primarily US-focused, but I believe this one applies for pretty much any country.

Sorry it took me so long to watch this. He essentially feels that trams are just glorified buses and identified issues with mixed traffic routes but modern teams and light railway are capable of leaving their tracks to circumvent obstacles.

We need a whole host of public transit options that are best suited for each circumstance of a given area. I want public transit so smooth that even if you tried getting lost you end up where you wanted to go with no clue on how it happened. (last bit is an over exaggeration since i don't know how feasible that actually is lol)

What region of the world have you experienced is close to this?
- Berlin, Frankfurt on Main, (many/most cities in Germany). Actually, most of the large cities in Europe, notably London. NY, DC, Chicago. Portland is getting close and Seattle (if they keep their build rates up) should have it in another decade. I got around really well in Boston and Toronto with just the metro/tram/bus systems.
  
  Tokyo's trains are phenomenal, as are most major cities in Japan.
  
  I'm sure that people would pitch in cities in China (I don't know much about them). There's plenty of places that have well integrated, city-wide, endemic transit systems that get you everywhere without a car.
It sounds perfectly feasible to me.

Depends on the road layout; if it's a long straight road then light railway makes sense. It's less maintenance, easier to operate, can move unhindered because it doesn't get stuck in traffic (edit: provided they don't share the roads).

For spaghetti road layouts though, I don't see the benefit, but I could be wrong since I'm no expert.

There is no reason rail has to be constrained to the road network. Eminent Domain is literally for things like this.

My pet conspiracy theory is that most bus routes are a false compromise sold to voters.

Another problem with light rail would be mountains. Trains don't like those. On the other hand, cable-cars and cog railway exists and seem to be viable solutions. The city of Lyon even has both and since the cog railway starts on a flat terrain, it is able to switch between both.

I would think adding railways to places would take a long time, cost a ton of money, and without enough population it doesn't make sense. I don't know what specific area of the world you are thinking, but most of the world is pretty empty outside of major cities, and most of them probably do have rail service.

I have old rail running right behind my house that people always want to start using again. It's in pretty rough shape so the eyes is it's easy to expensive to get it up to spec and the amount of public interest is too low that it become unfeasable.

Buses on the other hand, can get plopped down instantly wherever they will fit on existing infrastructure. They can go where the demands is. You can have a spare one on the lot. I'd think it's easier to become a bus driver than a conductor. And ultimately if you need more buses, just but another, and if you decide to scrap the program, sell the bus and you have no useless remaining infrastructure.

Overall I'd it had the choice to take a bus from A to B or rail, I'd probably choose rail I'd the pickups and drop s were the same, but again, that's also much harder to do with a train. There's room for both, but here I think trains make more sense for longer distances and buses for local.

I was initially conceiving this point as a venn diagram, but I guess it works like this as well.
(fuck cars/fuck bikes)

Fuck bikes?
- Tramlines are a nightmare for cyclists - the tracks are just wide enough for a bike wheel to get jammed in them, and what happens next shouldn't need any explanation. One of the professors in my undergrad met his maker that way, and it was part of my own education when first moving to the city as well. Beyond anecdotal evidence, the statistics are not pretty.
  
  Of course there are good things to be said as well - I generally prefer the tram to buses, and especially when it has its own dedicated lane outside of traffic (ideally in a green area) it can be both a beautiful green space and a great alternative to cars. But if it has to share space with other traffic, which is usually the case, it comes at a cost that is greater than just the one of construction.

If you design your bus system like a light rail system without rails, you magically get most of the benefits for far less cost: https://youtu.be/fh1IaVmu3Y8

IMO it should be a progressive transformation. First light bus coverage, then more frequent busses and longer busses, then once the line is packed elevated light rails with remote control. The goal should always be to carry more people with less effort. Busses can be deployed quickly. Rails are a better long term solution.
This video is so full of American stereotypes about transit and bad examples of what is considered improvement because you're having 10k instead of 3k riders per day in a city with an urban area of more than 600k people?! I think you could have a pretty sensible network that better serves people with the money poured in the UVX. The initial cost of the BRT is higher than that of light rail but with 10k riders per day do you even need a BRT? BRT also is not direct replacement for the tram or light rail, it doesn't offer the same capacity and ride comfort. Also the queue jumps mentioned in the video are potentially lethal to cyclists.
I also want to eliminate rubber (tyre) wastage?

Sorry, we don't have many trams in London, is the issue overly thin wheels like that of racers?