Roads, pavements and kerbs

Adoptable roads are built to the highway authority's published standard, layer by tested layer: formation prepared and proof-rolled, sub-base laid and compacted in lifts with plate-bearing or density tests to prove it, kerbs bedded and backed in concrete to string lines and level pins, then base and binder courses of asphalt paved and rolled, and the surface course held back until the construction traffic is done with the road. Falls are set to the gullies, because a road that ponds is a complaint that photographs itself.

Kerbs, footpaths and hard landscape carry the detail the public actually touches. Kerbs on concrete beds with proper backing hold the carriageway edge; flags and block paving go on their own compacted, screeded beds with rigid edge restraint - a creeping edge restraint is a spreading pavement. Dropped kerbs and tactile paving follow the adopting standard exactly, and ironwork - covers, frames, gullies - is set to finished level in mortar beds and adjusted to the surface. Rocking or sunken covers are the classic defect, and every one of them was set in a hurry.

Testing is per layer because failure hides downwards: a soft sub-base passes the eye and cracks the surface course within a year by reflective cracking. Drainage crossings and service ducts go in before the carriageway closes over them. Asphalt has its own disciplines - delivered temperature, rolling windows, weather limits - handled by the specialist surfacing gang, and the records of temperature and compaction are kept per load. Adoption inspections walk the finished work with checklists, and the as-builts for every buried service under the road go into the file.