The problem in Europe for freight trains is that Europe generally doesn't have as long routes as the US and on long routes in Europe you cross different countries, which have incompatible voltages and power systems, different signaling systems, etc. which makes it complicated to run trains across. Not to mention countries outside the customs union, where extra processing is needed.

On short distances a railway is simply less efficient than trucks.

Also companies have optimised their storage and logistic chain to expect for example one truck each day instead of a train each week and thus are using the road as storage facility.

Freight is also less attractive when you can't double-stack the containers because electric wires and tunnels are too low. I understand this to be the case on many European rail lines. In America where freight trains play a larger role in the economy than in Europe, most rail isn't electrified and double-stack freight trains are common.

For double height trains however go a bit slower, I think. In the denser populated Europe, with tracks shared with passenger service that is an issue as overtaking them takes even more infrastructure and regular stopping and accelerating again. Whereas in US there are large parts where they can simply go their speed for a long distance, which makes it really efficient.

Yes - it doesn't have to be either-or, if you're really committed you can lay extra tracks so passenger trains can overtake the freight trains. Especially in the US, where there tends to be a lot of space, this shouldn't be an insurmountable obstacle. Or run freight trains mostly during the night, as they do in Europe. However, of course we're talking of different scales here: a domestic flight in the US can be twice as long as a flight from say Rome to London.

Most of the places in the US where passenger rail would have the highest utility are the same places where there isn't a lot of space. That being said, it's still possible to make happen with high enough density (e.g. the Northeast megalopolis, which has usable, if expensive, passenger rail).

>usable, if expensive, passenger rail

Part of it is that the Northeast Corridor has to pay for basically the entire rest of the country where Amtrak almost universally loses money.

The other is that Acela specifically is priced to be more or less just competitive with air on the BOS-NYC and NYC-DC legs. (Acela doesn't really work for the most part to travel the entire length of the corridor.)

I almost never take Acela if I'm paying myself because the electrification work done for Acela made the regular regional train only about an hour slower for the BOS-NYC leg. (They used to have to switch engines in New Haven.)

Looking back at my last trip to the US with everywhere SUVs I'm not sure if that is so environment friendly compared to Europe where "normal sized" cars are more common.

Is it really an either/or situation? Is there absolutely no way to ensure both can work a bit better on the rail that they share? I genuinely don't know, but it was mentioned that the freight gets priority over passenger rail which suffers as a result. So it definitely sounds like this is by design, and that there's room for improvement that would allow both coexist in cases where they absolutely cannot use separate rail.

Freight does better when it is slow and cheap per ton mile. They also tend to be long to save on labor costs.

Passenger rail is pretty much the direct opposite, requiring fast acceleration and speed. So the two do not mix well (freight trains will slow down passenger trains.)

The only country that operates both high speed rail and freight successfully, by China, literally built a whole separate new high speed network to reserve for passenger trains and to leave freight the freed up space on legacy lines.

When we run short of railways, we build another one.

A bit like what the US does for roads.