Sorry but simply not true, Diamond Crossings ARE used extensively in Europe and are certainly NOT as you describe “crossings with traffic lights” !!
Example 1, a complicated Diamon Crossing junction outside Newcastle Station inthe UK,
https://pbs.twimg.com/media/CHt1aEXXAAAHDxl.jpg
That is an extreme and very complicated example, here is a more common example which you will find in EVERY rail network in Europe at some point, I guarantee it,
http://www.deathbyhealthandsafety.co.uk/safetyvalve/cheshunt.html
That page had several different views of a junction near Cheshunt in the UK and you can clearly see how usefull the diamond crossing is. The very name comes from the Diamond shape it makes when the first line crosses over the second to enable the lines to branch from each other. Basically, ANY double track line that wants to split into two double tracks MUST USE A DIAMOND CROSSING!! So sorry, to say they are not common in Europe is just plain wrong.
