Rutting is the longitudinal vertical deformation of a pavement surface in a wheelpath, measured relative to a straight edge placed at right angles to the traffic flow and across the wheelpath, with a length/width ratio greater than 4:1
Local Government & Municipal, Glossary of Roads & Transport Terms, (LGAM) Knowledge Base (Encouraging Collaboration & Konowledge Sharing), Australia 2013. http://lgam.wikidot.com/glossary-of-roads-transpor t-terms/p/10, (Road Trfc and Transp Sfty - Brit) {603}