Site clearance and formation
Removing what is there, excavating to formation level, and preparing the subgrade. Formation is proof-rolled to show that it will carry the construction above it. Soft spots are dug out and replaced rather than covered over, because a weak area under a new pavement will find its way to the surface within a season or two.
Sub-base and capping
Granular material laid and compacted in controlled layers to spread wheel loads and provide a working platform. Where the subgrade is poor, a capping layer goes in beneath the sub-base to bridge it. Layer thickness is governed by what the material and the compaction plant can achieve. Laying too thick means the bottom of the layer is never properly compacted.
Binder course
The structural asphalt layer. It carries most of the load-spreading duty within the bound construction and provides the regulating surface the final layer is laid on. Its level and regularity determine the finished level, so it is where accuracy is won or lost.
Surface course
The running surface. It has to be dense enough to keep water out, textured enough to give skid resistance, and laid within a temperature window that is measured in minutes rather than hours. Joints are the weak point of any asphalt surface and are formed and sealed deliberately rather than left where the machine stopped.
Kerbs, edgings and channels
Kerbs define the line and level of the whole job and are usually set before surfacing so that everything else is built to them. They also contain the pavement edge, which matters more than it appears: an unsupported asphalt edge fails first and fails quickly.
Drainage
Gullies, connections, channel drainage and outfalls. Falls are set so that water leaves the surface rather than standing on it, because standing water is both a safety problem and the beginning of pavement failure. Ironwork is set to final level and bedded so that it does not rock under traffic.
Patching and reinstatement
Localised repair, and making good after other people's excavations. A reinstatement is only as good as its edges: cut square, to full depth, into sound material, or the patch fails around its perimeter regardless of what goes in the middle.
Markings and signs
Road markings, studs and signage complete the job. Markings are applied to a clean, dry, cured surface; applied too early or onto a dirty one, they lift.