A two coat seal is a road surface treatment consisting of a layer of bitumen with large aggregate that is sealed over with another layer of bitumen with smaller aggregate
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}