The accident happened on the southbound carriageway of the M1.
Англо-русский строительный словарь. — М.: Русский Язык.С.Н.Корчемкина, С.К.Кашкина, С.В.Курбатова.1995.
проезжая часть (дороги)
• (British) one of the two sides of a motorway where traffic travels in one direction only usually in two or three lanes