overtaking' signs would be repeated at the beginning of the length subject to two-way working, and probably at intervals along it.
78. Finally, we were told that though elaborate arrangements had been made for gritting the road before ice was likely to form there might still be a need for signs to give warning of icy conditions in those isolated spots where it was likely to form without the whole road being affected-e.g. under and over bridges. Similar signs might also be erected, at the discretion of the highway authority or the police, at entrances to the motorway when icy conditions were likely, or in prolonged icy conditions.
79. We think there is much to be said for signposting accidents and road works in the same way, and we accordingly suggest that, in order that the same signs. may be used in either type of emergency, the first warning sign proposed by the police should have 'Accident' on one side and 'Road works' on the other (figures 18 and 19); it should be rectangular, and sited 900 yards in advance of the obstruction. We feel that this sign should be preceded by a more general warning, and we recommend that for this purpose the opportunity should be taken to move closer to European international practice by using a sign (figure 17) similar to the European sign for an unspecified hazard, adapted however so that the symbol forms an exclamation mark; this adaptation of the European sign is widely used in Belgium. We recommend that it should be sited 1,000 yards before the obstruction. The 'No overtaking' sign, which is rectangular, is illustrated in figure 20; it should be placed 600 yards before the obstruction. With regard to the suggested sign imposing a speed limit, we understand that the Motorways Traffic Regulations do not empower the police to impose such a restriction, and in these circumstances we have had to limit the message on the sign, which is also rectangular, and should be sited 300 yards in advance of the obstruction, to the word 'Slow' (figure 21). The rectangular 'Two way traffic' sign we recommend is illustrated in figure 22 and the 'Ice' sign, which is triangular, in figure 23. All these signs have reflectorised white symbols and lettering on a red non-reflectorised background with a red reflectorised border. This colour scheme ensures that in daylight the inscriptions will appear white on a solid red background and at night in headlights they will appear white on a dark ground within a red border.
80. We also recommend a 'Fog' sign (figure 24), to be placed at entrances to the motorway, and possibly at intervals along it, when fog is likely to be encountered along the route. The basic design of this sign is similar to that of the 'Ice' sign.
81. The signs should obviously be as large as possible in order to attract maximum attention. On the other hand they must be easily portable, and we accordingly recommend that the triangular signs should be four feet high and the rectangular signs (with the exception of the 'Two way traffic' sign, which will, we understand, be fitted into slots to be provided at all gaps in the central reservation, and can therefore be as high as six feet) should be four feet long by two feet high. We are satisfied that signs of this size will be sufficiently prominent.
82. We have not considered the design of the cones used to guide traffic past the obstruction, which properly regarded are articles of street furniture, but we think that they should be supplemented by signs with a white arrow on a blue
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