Maintenance, a complex procedure, requires the Highway Authority to adopt certain standards and policies with regard to maintenance of the roads for which it is responsible. The standards for motorways and trunk roads have been laid down by Highways England. Highways must be divided into categories, with an inventory made of each road’s width, length, drainage, verges, footways, signs, and markings. In urban areas, higher standards will normally be required than is the case in rural areas, for both highway and cleansing needs. Verges in urban areas tend to require more attention than in rural areas. The tell-tale signs are crazing, breaking-out of random areas to reveal the substrate. Excessive variations in thickness of bituminous surfacing layers due to the materials being laid on a poorly shaped substrate should be avoided as they can cause variations in initial compaction with subsequent variations in durability of the surfacing and reduction in the riding quality.