A Roman bridge carried a road over a river or valley, built of timber, stone or both. The Romans were the first to build large, permanent bridges, many with semicircular stone arches, and some are still in use.
Key takeaways
- Early Roman bridges were wooden, and stone arch bridges came later.
- Most stone bridges used concrete, and builders used cofferdams to work in the riverbed.
- Fords, timber bridges and pontoon bridges were used as well as stone bridges.
- Our map shows no bridges: a road such as the 372 km Fosse Way is drawn as an unbroken line even where it crossed rivers.
How Roman bridges worked
The Romans were the first civilisation to build large, permanent bridges. Early bridges were of wood, and stone bridges appeared later. Pontoon bridges, made of boats laid side by side, served armies [1].
Timber. Early wooden bridges stood on trestles or on piles driven into the riverbed, and builders used interlocking cofferdams to drive them. Timber bridges could be burned or taken down quickly in a fight [1]. In Britain there were small timber bridges and larger bridges of stone and wood [1].
Stone. Stone bridges used arches. Most arches were semicircular, though some were flatter, which let floodwater pass and reduced weight [1]. Most stone bridges used concrete, and the outside was faced with cut stone or brick [1]. Piers were thick enough to resist the thrust of the arches and often had pointed cutwaters on the upstream side [1].
Building in water. To build piers, the builders diverted the water with watertight walls called cofferdams, usually in the dry season [1].
Alternatives. Not every crossing had a bridge. Roads also crossed rivers by fords, and where ground was wet, causeways were built on piles with stone sunk between them [2]. For wet ground see causeway.
Surviving bridges are rare and biased towards the most solid ones. Scholars disagree about when stone bridges began, and many bridges lost their original parts over time [1].
An example from our data
The Fosse Way runs for 372 km in our data, and Watling Street for 352 km. Both crossed rivers, but the map draws them as continuous lines. Itiner-e records the route and how certain it is, not the crossing points or what carried the road over. Where a bridge is known from other evidence, you will not see it here. 2,983 Roman places from the Pleiades gazetteer are matched to the network, but that is a list of places, not of structures.
The thing people get wrong
People often assume every Roman crossing was a stone arch. Many early bridges were timber, and some crossings were fords. Because timber rots and burns, the lost bridges are far more numerous than the surviving ones, so surviving Roman bridges give a skewed picture of how rivers were crossed.
Frequently asked questions
Are there Roman bridges still standing?
Yes. A few, such as the Pons Fabricius in Rome, are still standing and in use .
Does the map show Roman bridges?
No. Itiner-e does not record bridges, fords or river crossings.
Sources
- Roman bridge, Wikipedia.
- Roman roads, Wikipedia.
- Every figure from our own map is worked out from the datasets on the data sources page (checked against Itiner-e version 2024 1.3).