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 :-)
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.
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.
This seems like a peculiar way to describe them? A trolleybus is just a bus with normal rubber tires, that's powered electrically by a caternary.
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.
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.
[1] https://en.wikipedia.org/wiki/File:Fuel_tax_in_OECD_countrie...
*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.
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.
My guess is where the downvoting come from :)
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.