My apologies if this has been posted previously, a, quick, search says not but anyway.................
http://www.fhwa.dot.gov/environment/fspubs/99232823/index.htm
Obviously very North American but contains some good history.
Richard
http://www.fhwa.dot.gov/environment/fspubs/99232823/index.htm
Obviously very North American but contains some good history.
Richard