My next review is of Roads in Roman Britain by Hugh Davies. Davies was a road engineer, and the study of Roman roads is a retirement project for him, which amused me since I am currently contemplating retirement. I don’t mean this pejoratively – I think in Roads he did a great job bringing together his expertise and the existing academic work in the area, as well as his own original research. He gained a PhD in 2001 from Reading University. In addition he has compiled a database of Roman road characteristics which is exactly my sort of thing.
The book starts with some basic definitions of what a road is and how it is structured. Davies focusses on the function of the road as a transport mechanism rather than as a boundary indicator, a navigation system or an expression of Roman power – uses I hadn’t really considered. As a structure a road has a route and a cross-section. I liked the quote from John London McAdam which basically said the function of the road cross-section was to stop the running surface becoming unusable as a result of water coming from above or below!
There is very limited primary documentary evidence for the Roman roads of Britain, there is the Antonine Iternary, tables of routes across the Roman empire which includes some routes in Britain and the Peutiger Tables, a sort of pseudo-map of roads across the Roman Empire of which Britain is only covered in a small fragment showing the far south east of the country.
This leaves us with archaeology, fortunately Roman roads in Britain have been excavated for many years. Less fortunately dating evidence is sparse in roads. Some roads identified as Roman may well date to medieval or even the 17th century when the turnpike roads were the first to match the quality of construction of Roman roads. It’s worth noting that none of the names used for Roman roads (Watling Street, Ermine Street, the Foss Way etc) are original – they are labels dating to the medieval period at earliest. It is not clear if Romans used any sort of naming for roads.
Archaeological practices have improved over the years, it is only really in the last quarter of the 20th century that it was appreciated that Roman roads are structures that were repaired and reconstructed over centuries.
I think the most interesting idea in this book Davis’s proposal for a reason for the straightness of Roman roads. He argues, unlike others, that the Roman’s must have made some sort of map before laying out roads and that the likelihood was that this was some large scale object possibly inscribed onto a floor. Under these circumstances straight road segments are the easiest to transmit to “the field”. It is easy to say “go to this point, build a straight road in this direction until you have gone this distance”, imagine trying to describe a more complex route accurately.
One of the recurring themes of the book is as to whether the Romans built roads to a strict pattern in terms of construction details and width. Justinian codified road classifications in the 6th century AD; an iter is pedestrian only, actus will allow a beast of burden, via will allow a cart however no numerical widths were defined. The Twelve Tables from fifth century BC says a straight section of road must be 8 pedes (Roman feet) wide on the straight an 16 on corners. However, on the ground road widths follow quite a broad distribution with a peak around 20 pedes (which is about six metres). This is wide enough for two-way cart traffic.
Based on the road surface (crushed stone/gravel) and the maximum gradients Davies suggests that Roman roads were designed for heavy carts moving at walking pace rather than fast passenger carriages. I was interested to learn the optimum gradients for carts are based on the rolling resistance of the surface balancing gravity (which becomes larger for steeper slopes). This is to avoid runaway carts since braking technology at the time was poor.
In the past historians have tended to the view that the Romans worked in a very regimented fashion. Davies comes down on the side of a more flexible approach determined by local factors. This is complicated in the archaeological record by repair and reconstruction activities, in some places there is evidence for 9 or 10 cycles of repair/reconstruction – sometimes this is as an addition on top of an older road but sometimes it is a widening of the route.
Davies observes that there is a difference in construction methods between the north and west of the country and the south and east with the north and west making greater use of stone. He attributes this to much more significant military use in the north and west, and better availability of suitable stone.
There is a chapter on Roman town plans which looked like it could be a whole separate book. Roman towns are typically built on a grid sometimes this grid is based around a Roman road alignment – suggesting road predates town and sometimes the road deviates to adapt to the town grid, suggesting town predates road.
Davies covers fairly briefly the development of the network over time, in terms of the military function of roads. The Royal Engineers estimated that the initial road from a Kent invasion landing point to London would have taken 1000 men about 15 weeks, a full version would take 3400 men about 3 years. The Roman road system was not fully developed until into the 2nd century AD – some 60 or so years after the invasion. London was not the transport centre of Britain at the beginning of the Roman occupation but became so over time.
This book is somewhat specialist, I enjoyed it because I’m interested in civil engineering and Roman history. It is short and readable, and I think provides a unique perspective.
