Drive north from London on the A1 and you are following, with considerable accuracy, the road that Roman engineers surveyed across the landscape of Britain in the first and second centuries AD. The A1's line between London and York — 195 miles, give or take the modifications of two millennia — follows the Roman route known as Ermine Street with a fidelity that says something profound about the durability of good infrastructure decisions. The Romans built straight. They built to a standard. They built to last. And in a landscape that had no competing road network of comparable quality, the lines they drew became the lines that subsequent centuries followed without quite understanding why.
Roman road-building in Britain began in earnest immediately after the invasion of 43 AD. The military requirement was absolute: legions moving across new territory needed supply lines, the ability to concentrate forces quickly, and communication routes that did not depend on the goodwill of local guides or the fordability of rivers. The surveying was done by the legion's engineers using a groma — a simple right-angle device mounted on a pole — which allowed straight lines to be projected across the landscape by sighting between poles set at intervals. The straight line was not an aesthetic preference. It was military logic: the shortest route between two points, taking the high ground where possible to maximise sight lines and drainage, avoiding marshy lowland wherever an alternative existed.
The construction method varied with local materials but followed a standard three-layer principle. The first layer was a foundation of large stones or rubble, set into a prepared trench. The second layer was gravel or crushed stone, compacted. The third layer was the surface material — smaller gravel, dressed stone, or local aggregate, cambered to drain water to the sides. A drainage ditch ran alongside the road on both sides. The whole construction, known to archaeologists as the agger, typically stood slightly raised above the surrounding ground level, sometimes quite conspicuously — in moorland and open countryside where erosion has not levelled it, the raised profile of a Roman road is still visible as a linear mound crossing the landscape.
Ermine Street — the A1's ancestor, running from London to Lincoln and then to York — and Watling Street — running from London northwest to Wroxeter and then to the Welsh borders — were the primary arteries of Roman Britain. Together with the Fosse Way, running diagonally from Lincoln to Exeter, and the road network of the north, they formed a system that connected every significant military installation and civil settlement in the province. A despatch rider could travel from London to York — the military headquarters of the north — in approximately four days using the road system and the official rest stations, the mansiones, that were sited at regular intervals along every major route.
The distance between stations was calibrated against the day's march of a legionary — approximately fifteen to twenty miles — so that troops moving along the road arrived at a rest point and a supply facility each day. The mansiones were not inns in the medieval sense; they were official facilities, required to provide accommodation, food, and fresh horses for government travellers carrying the diplomata — official passes that entitled the holder to use the imperial post system, the cursus publicus. Private travellers used the same roads but made their own arrangements at the settlements that grew up alongside the military facilities.
Where Roman roads cross Britain today, they are often most visible in the landscape precisely where subsequent centuries disturbed them least. Stane Street, running from London to Chichester across the North Downs and the South Downs, can be walked in sections where it crosses National Trust downland — the agger raised as a bank through woodland, the surface material long gone but the foundation's subsidence visible as a clear linear feature. The Ridgeway, following the high ground of the Downs before descending to Silchester, is partly Roman over a prehistoric trackway. Akeman Street across the Cotswolds follows a line that is visible in field boundaries, hedgerows, and the occasional stretch of surviving metalling.
Dere Street — the principal military road of northern Britain, running from York through Corbridge to the Antonine Wall — crosses the Cheviot Hills in sections that are among the most dramatically preserved stretches of Roman road in Britain. Walking the stretch between Chew Green and Pennymuir in Redesdale, the agger rises to knee height in places, the original road surface lying under the turf, the course arrow-straight for mile after mile across the Northumberland moorland. This is the road that the legions used to supply Hadrian's Wall and the forts beyond it, and it has the specific quality of all great Roman engineering in landscape: it looks like it is still trying to get somewhere. Its straightness is purposeful. It announces intention.
The relationship between Roman roads and modern transport corridors is not accidental. The surveyors who laid out the Roman routes chose alignments based on topography — avoiding major obstacles, crossing rivers at the most stable and shallow fords, taking the high ground between valleys for drainage and security. These are the same principles that modern road engineers apply, and in a landscape shaped by glaciation and river erosion, the optimal corridors for north-south travel in Britain have not changed. The A5, following Watling Street, takes the same line across the Midlands that Roman engineers identified as optimal in the first century. The railway builders of the 1840s, independently reasoning from similar topographic principles, frequently converged on the Roman alignments.
The place names of Britain carry the road network in their etymology. Any settlement whose name contains street, strat, or stret — Stratford, Streatham, Stretton, Streetly — typically sits on or near a Roman road. Chester, caster, and cester indicate Roman military camps (castra): Colchester, Chichester, Winchester, Rochester, Leicester, Lancaster, Doncaster. Wick, wich, and wick often indicate Roman settlement or salt-working sites associated with the road network. Reading the place names of the English landscape is reading the ghost of Roman infrastructure.
Not all Roman roads are visible. The most important discoveries of Roman road networks come from aerial photography — in dry summers, when crops over the compacted gravel and stone of a buried Roman road grow differently from crops over surrounding soil, the road's line appears as a crop mark, a shadow in the grain that a photograph from altitude reveals. The National Collection of Aerial Photography holds thousands of images of Roman road crop marks across Britain, adding to the network map each dry summer. Ground-penetrating radar surveys have added more. The Ordnance Survey maintains the most comprehensive published record of Roman roads in Britain.
The Vindolanda tablets — those intimate documents of life on Hadrian's Wall — include a fragment that mentions road maintenance, a soldier requesting materials for repair work. The road network that connected the Wall forts to each other and to the south was maintained by the garrison troops as a regular duty. The roads made the Wall possible: without Dere Street and the supply route from York to Corbridge and the Wall, the garrison could not have been fed, equipped, or reinforced. Infrastructure and military presence were inseparable, and the roads embodied that connection in stone.
LocationsLive's Hadrian's Wall walking experience follows sections of the Wall's own associated road system — the Military Way that ran behind the Wall, connecting each fort and milecastle, and the Stanegate that preceded it as the frontier road. Walking the Military Way east of Housesteads, you are walking a road that Roman soldiers walked as a routine duty, a road that is still there under the turf, its stones still set in the original gravel bed. For more on how the Roman infrastructure of the north operated and what it was designed to serve, the posts on life in Roman York and on the women of Hadrian's Wall place the roads in the human context they were built to connect.
The A1 will carry you from London to Edinburgh in about nine hours. Ermine Street and its northern continuation, Dere Street, carried a Roman courier from London to York in four days and from York to the Wall in another two or three. The route is essentially the same. The speed is different. The decision to take this line across Britain, made by engineers who had never heard of internal combustion and who measured distance in millia passuum — thousands of paces — has been confirmed by every subsequent generation of travellers who needed to go the same way. That is what it means for infrastructure to be right: that it stays right across two thousand years of change.
