What is a roman road?

What a roman road is

Historic England's scheduling texts describe two main forms: a broad agger of several layers of graded material between widely spaced boundary ditches, and a narrower agger of two or three layers with drainage ditches. A typical main road had a carriageway about 5 to 8 metres wide, surfaced with compacted gravel or flint over a foundation of larger stones. Estimates of the total length differ: one Historic England scheduling text gives about 9,500 miles of Roman road built in Britain, while about 2,000 miles of main paved roads is the figure commonly cited for the trunk network. Only a small part survives as earthworks, because many routes lie under modern roads and others have been ploughed out or stripped of their stone. Ivan Margary's Roman Roads in Britain gave the known roads the reference numbers still used today.

How roman roads look on LiDAR

Where it survives, a Roman road shows as a long, straight, low bank (the agger), often with a shallow ditch or a line of quarry pits along each side, changing direction at sighting points, often on high ground. Because the agger may be many metres wide but only a few tens of centimetres high, a local relief model shows it far better than hillshade, which loses it where the road runs parallel to the light. Hedges, parish boundaries and footpaths often follow the line, and following the alignment across the model can bridge gaps between surviving stretches.

See LiDAR visualisations explained for what each method shows.

What can look like one

Turnpike roads, straight enclosure roads of the 18th and 19th centuries, disused railway and tramway embankments, canal towpaths, field banks and pipeline trenches can all form straight linear features. A Roman road usually has a broad, low, cambered agger with side ditches and keeps its alignment regardless of later field boundaries.

Protection

Some well-preserved stretches of Roman road are scheduled monuments, protected in England by the Ancient Monuments and Archaeological Areas Act 1979 and in Wales by the Historic Environment (Wales) Act 2023, but most of the network is not designated.

Examples on the LiDAR

Where they are

Counties with the most roman roads that have a page here.

More examples