10.12 Use of diagram 550.1 to indicate an informal crossing place should normally be considered only where the visibility distance is less than specified in table 10-2. These distances are based on one step below the minimum desirable stopping sight distance (see para 10.7).
| 85th percentile speed | Visibility distance |
|---|---|
| (mph) | (m) |
| Up to 40 | 80 |
| 41 to 50 | 110 |
| 51 to 60 | 150 |
| Over 60 | 200 |
.svg)
May be used with diagram 570
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May be displayed only between January and May.
May be used with diagram 570
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May be used with diagram 553, 572 or 573
10.13 The sign to diagram 551.1 may be used only at a site which is approved as a migratory toad crossing by or on behalf of the Secretary of State (see para 1.2) as a migratory toad crossing. A list of currently approved sites is available from the Froglife Trust (e-mail info @ froglife.org). The sign may be accompanied by the distance plate shown in diagram 570. It may be displayed only during the months of January to May (direction 28). Signs must be removed or covered at other times of the year; it is recommended that flap-type signs be used to facilitate this. Traffic authorities that neglect their statutory responsibilities in this regard undermine the effectiveness of the sign.
10.14 The sign to diagram 551.2 may be used where wild fowl are habitually found in the road, such as sites near ponds and watercourses. It may be combined with diagram 570, displaying a distance, e.g. "For 150 yds", in accordance with Appendix C.
CATTLE GRIDS
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May be used with diagram 570
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May be used only in combination with diagram 552.
The direction of the arrow may be reversed
10.15 A cattle grid on a public road should always be preceded by the cattle grid warning sign to diagram 552, as it might otherwise catch drivers unawares. Grids are especially hazardous for two-wheeled traffic. Signs should normally be sited at the standard distances set out in Appendix A. The plate to diagram 553 indicating the direction of the by-pass for horse-drawn vehicles or accompanied animals can
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