The construction labor rate difference between the US and Europe is surprising, especially given the stronger unionization rules in Europe.
"Although the material and equipment costs are similar (within 10%) for projects in the United States and in Europe, labor costs are substantially higher in the United States as outlined above. For example, in California the average billing labor rates for qualified tunnel workers is about $70/hr and the average New York labor rate of qualified tunnel workers is at over $100/hr, whereas in Germany (one of the high labor rates countries in Europe) the comparable labor rate is about $30/hr."
"Although the material and equipment costs are similar (within 10%) for projects in the United States and in Europe, labor costs are substantially higher in the United States as outlined above. For example, in California the average billing labor rates for qualified tunnel workers is about $70/hr and the average New York labor rate of qualified tunnel workers is at over $100/hr, whereas in Germany (one of the high labor rates countries in Europe) the comparable labor rate is about $30/hr."