So you don’t care about the total sum of CO2 involved in the project? Then what’s the point of your question?
Are you suggesting we only invest in investing in solutions with zero C02 emissions?
The emissions from the construction of the high speed rail lines considered here is in the range of 58 t – 176 t of CO2 per km of line and year.
Compared to a single highway lane
building a lane-mile of highway releases between 1,400 and 2,300 tons of CO2.
So the production and installation would be several magnitudes less than building a single lane highway.
Maintenance is a more difficult thing to estimate for trains, as most environmental impact studies include the maintenance and disposal of the actual trains into the equation.
If you want to you can figure it out yourself, but I can guarantee you that it’s lower than anyother transportation network infrastructure.