Here you can find a good paper on railway noise in Europe:

http://www.google.hr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&ved=0CFoQFjAF&url=http%3A%2F%2Fwww.uic.org%2Fdownload.php%2Fpublication%2F516E.pdf&ei=nfPXUsXgL-SFyQPp_4DwDg&usg=AFQjCNH6F0FvgzAbry05_ZizIsWRGG9vAw&sig2=AiSP_RGf4R2cnN9Sltq6ZA&bvm=bv.59568121,d.bGQ

There is also a very good study performed by Portland State University, but it is more on noise from train horns. You can find it (it is free) at the following web-site:

http://voorheesvilleqz.com/documents/SoundLevelDisturbancesofFreightTrainHorns.pdf

Also, here you can find interesting document of EU, which warns that it is necessary to reduce the noise from trains:

http://ec.europa.eu/danmark/documents/alle_emner/transport/080708_groentransport-10.pdf

I hope I helped you at least a bit!

Thank you Stanislav!