A ford is a much cheaper form of river crossing than a
bridge, and it can transport much more weight than a bridge, but it may become impassable after heavy rain or during flood conditions. A ford is therefore normally only suitable for very minor roads (and for paths intended for walkers and horse riders etc.). Most modern fords are usually shallow enough to be crossed by
cars and other wheeled or tracked vehicles (a process known as "fording"). Fords may be accompanied by
stepping stones for pedestrians. The
United Kingdom has more than 2,000 fords, and most of them do not have any way of stopping vehicles from crossing when the water makes them impassable. According to
The AA, many flood-related vehicle breakdowns within the UK are at fords. In dry weather, drivers become aware of a ford by crunching across outwash detritus on the roadway. A
Bailey bridge may be built off the mainline of the road to carry emergency traffic during high water. At places where the water is shallow enough, but the material on the riverbed will not support heavy vehicles, fords are sometimes improved by building a submerged
concrete floor. In such cases, a
curb (kerb) is often placed on the downstream side to prevent vehicles from slipping off, as the growth of
algae will often make the slab very slippery. Fords may be also equipped with a post indicating the water depth, so that users may know if the water is too deep to attempt to cross. Some have an adjacent footbridge so that pedestrians may cross dryshod. Fords were sometimes the only way to cross bodies of water, such as at the Milkhouse at
Rock Creek in Washington DC. However, the regular use of this ford has been superseded by bridges. The crossing remained open for "adventurous" drivers until 1996, when the
National Park Service closed the ford to cars.
Watersplash ,
Isle of Wight. The one shown is over
Lukely Brook, a tributary of the
River Medina. A road running below the water level of a stream or river is often known as a "watersplash". It is a common name for a ford or stretch of wet road in some areas, and is sometimes also used to describe tidal crossings. They have become a common feature in
rallying courses. Some enthusiasts seek out and drive through these water features, recording details (such as wave created, position, and access) on dedicated websites. There are many old fords known as watersplashes in the
United Kingdom. Examples are at
Brockenhurst in
Hampshire,
Wookey in
Somerset, and
Swinbrook in
Oxfordshire. Some of these roads are being replaced by bridges, as they are a more reliable form of crossing in adverse weather conditions. Some very spectacular watersplashes can be found in diverse locations.
Australia has the
Gulf Savannah, and others may be found in
Canada,
Italy,
South Africa, and
Finland. They are also found on some
Tennessee backroads, where they are referred to as "underwater bridges". In
Israel and part of the British areas under the
mandate a low water crossing or watersplash had been known as the "Irish bridge" in reference to the
Anglo–Irish war. ==Placenames==