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|A cattle grid in Hampshire|
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Cattle grids are used across the country as an alternative to installing fencing along the roadside. They are generally found on unfenced roads through grazing lands, in the line of a fence, and are also used in moorland areas, again in the line of fences, to control the movement of wild animals, particularly deer and wild ponies. In recent years, their usage on main roads has diminished, often without the installation of any alternative solution.
Lighter-weight cattle grids give the appearance of a metal gate laid across a pit in the road. Constructed out of tubular galvanized steel, the tubes run across the width of the road, with flat transverse bars at intervals to keep them spaced apart. The bars are spaced sufficiently that animal hooves would slip off and into the space between, without trapping the leg. This normally works well, providing adequate deterrent to animals trying to cross the grid. However, a few sheep have been known to find a way to roll over the grids! It is not unknown for tubes on these grids to become slightly buckled over the years from the traffic passing over.
These light-weight grids predominate on single-track roads, but occasionally two are used side by side on wider routes with low traffic volumes. The sides of the grids are fenced in, and in moorland areas these fences are often sis feet high or more in order to prevent deer jumping them.
Heavier grids are used on busier roads, where a higher traffic volume may result in the light-weight grids wearing out too quickly. These grids use steel I-Beams in place of the tubes, and use heavier gauge steel. Again, they are spaced out by transverse bars. Whilst this may appear to be easier for livestock to cross, with flat topped beams, in practice the higher traffic volumes lead to a shiny surface which it is difficult for animals to get a grip on.
Maintaining full access
In nearly all cases, cattle grids are accompanied by a gated access to one side, to allow the movement of animals as necessary. It also allows pedestrians and cyclists to proceed if they are unhappy about using the grid itself. This also provides a pull in / passing place for traffic on either side of the grid.
In recent years, with the development of off-road cycle routes, there have been a number of narrow grids installed on the routes to remove the disruption to cyclists of negotiating the gate alongside. Some such grids seem very narrow, especially when taken at speed, and in consequence they hardly produce the intended benefit, since cyclists need to take the grid slowly to ensure handlebars don't scrape fences!
Cattle grids are nearly always signed in advance, with a cattle grid warning sign. Sometimes this will have an indication of distance too, but this can be omitted when the grid is within visible distance.
Additional signage on the gate alongside, or nearby, directs horse-drawn vehicles and animals to use the gate to ensure safe progress. This is generally coupled with a "keep gate closed" sign, to maintain the integrity of the livestock barrier.