The purpose of this selection guide is to assist those responsible for vertical road signalling projects in the application and use of the standards UNE-EN 12899-1, UNE 135334, UNE 135340 and the European Assessment Document (EAD), concerning To the retroreflective sheets, and in particular, to the photometric prescriptions. This guide offers a number of solutions to the use of retroreflective materials and does not exclude other possible alternatives.