(paragraph 118), with the addition of the forward destination of the motorway, but this would produce a sign of such enormous proportions that we rejected it.
120. The fourth advance direction sign should be sited at the beginning of the second deceleration lane. It contains the junction symbol, the forward destination of the motorway, the destination of the slip road and the route- number of the intersecting road, and is in all respects identical in design with the advance direction sign sited at the beginning of the deceleration lane at ordinary junctions along the motorway (paragraph 88 and figure 30).
121. Exit distance markers (paragraph 91 and figure 31 ) should of course be used at the junctions with both exit slip roads. A supplementary exit sign (paragraph 94) should also be erected at the second junction.
Junctions Close Together
122. In all the proposals we have made so far for the signposting of junctions along the motorway we have recommended that the first direction sign for each junction should appear a mile in advance. This recommendation presupposes that all the junctions will be more than a mile apart, as otherwise the signposting of one junction might overlap the signposting of the next, with a consequent risk of confusion to drivers. There will be cases, however, where two junctions are a mile apart or less, and where some modification of the direction signing arrangements we have already recommended will clearly be necessary. We discuss below three alternative ways in which this might be done: the alternative adopted will very largely depend on traffic conditions at the junction or junctions concerned.
123. The first and simplest alternative is merely to dispense with the one-mile advance direction sign for the second junction. This means that the first sign for this junction would be only half a mile in advance, and we do not therefore consider that this alternative should be employed lightly; it should obviously not be used, for example, where a substantial volume of traffic leaves the motorway at the second junction.
124. The second alternative also involves the omission of the one-mile sign for the second junction, but would involve in addition the use of an overhead sign instead of a roadside sign at the half-mile point. As we have already pointed out (paragraph 105), an overhead sign is visible from a considerable distance, and this will do much to offset the disadvantage of siting the first advance direction sign in such comparative proximity to the junction to which it relates. This is an important consideration at junctions where a large volume of traffic leaves the motorway. We have already recommended three different types of overhead sign (figures 35, 36 and 45), and it will be found that one of them, appropriately adapted, will be suitable for use here.
125. The third alternative involves signposting the exit slip roads of the two junctions in the same way as the two exit slip roads of a cloverleaf junction (paragraphs 116-121). Where the junctions are a mile apart, only the signs at the beginning of the first deceleration lane need show both; where they are nearer half a mile apart the half-mile sign for the first junction should also show both, with an indication of distance against each arm representing a slip road.
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