disc to indicate the route to be followed past the obstruction (figure 25); these signs, with a red background, were recommended in our interim report, but in deference to the views since expressed by several interested organisations we now revert to the conception of a white on blue sign to conform with international practice. We also recommend that where it is necessary to close one carriageway completely prohibition of entry should be indicated by a sign consisting of a white bar on a red disc (figure 26); this sign was also recommended in our interim report. We propose a three-foot disc for each of these signs, which should be reflectorised.
83. Finally we recommend a reflectorised sign reading 'Road clear' (figure 27), to be placed after the obstruction, or after ice. This sign, which is white on blue, will we feel give a helpful indication to the motorist which is conspicuously lacking in similar circumstances on all-purpose roads.
84. We understand that some highway authorities may wish to use larger versions of these signs for pre-arranged repairs, when the signs could be erected more at leisure. We should naturally welcome this, provided the signs are erected in accordance with the same code of practice as the emergency signs.
Leaving the Motorway
Intermediate Junctions
Advance Direction Signs
85. As has already been mentioned, it is essential that drivers should receive sufficient warning of an exit to enable them to get into the left-hand lane in readiness to turn off the motorway without endangering other traffic. This means that signs must be provided well in advance of the exit and that they must be repeated so that there is no risk of other traffic obscuring them at the crucial time. We propose the provision of three direction signs in advance of the exit and one at the exit itself.
86. The first advance direction sign (figure 28), sited one mile in advance of the exit, is intended as a primary warning that an exit lies ahead. Its principal features are therefore the junction symbol and the distance to the exit. The route-number of the all-purpose road which can be reached from this junction is also included.
87. The second advance direction sign (figure 29), sited half a mile in advance of the exit, repeats the information contained in the first and adds the names of places which can be reached by leaving the motorway at the junction. It again includes the important reference to the distance to the exit.
88. The third and final advance direction sign (figure 30), sited at the beginning of the deceleration lane, in turn repeats the information contained in the second and adds the forward destination reached by driving on along the motorway. The omission of any reference to the distance to the exit will indicate that the driver has reached the point where his path along the deceleration lane begins to diverge from the main line of the motorway.
89. It will be seen that in the junction symbols in each of these signs, the arm representing the motorway is just off vertical. This not only gives prominence
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