and waste of sign space. While place names on map type signs without panels must obviously not be overcrowded if they are to be clearly seen to be related to the route symbols, we think that by careful design this can be avoided.
136. We have, therefore, considered what changes should be made in our present system of directional signing. In this country where the road pattern is so complicated, we think it would assist travellers in finding their way between important towns if a system of Primary routes other than motorways was established, the roads in which would be clearly distinguished by having directional signs of a particular colour. Moreover, we foresee that this distinction might eventually enable a code of improved driver conduct, aimed at improving traffic flow and safety, to be applied generally to these Primary routes. This might, for example, forbid parking except where it is specifically allowed and also all U-turns and stopping within a given distance of a junction. Such general measures would obviate numerous local regulations and would lead to greater uniformity in the enforcement of traffic regulations throughout the country.
Motorway style signs modified as mentioned below and with white lower case lettering on a green background would be extended so as to be the main distinguishing feature of this new national Primary route system. For all other roads we recommend that directional signs should carry legends in black on a white background , a colour combination which has merit for the smaller signs which would be required on some of these roads because of its good target value ; otherwise the signs should be in the same style as those recommended for Primary routes. In all cases letter heights and consequently sizes of directional signs should be based upon vehicle speeds and the layout of the roads on which they are erected.
137. We think that the selection of roads to form the Primary route network is best left to the Departments concerned in consultation with highway authorities. For their guidance we recommend that the network should include:—
(i) roads carrying a considerable volume of medium and long distance traffic;
(ii) roads which avoid urban centres;
(iii) roads of traffic importance for the area concerned;
(iv) such additional roads as are necessary as link roads so as to form a coherent national network.
It seems to us that if these criteria were adopted the resultant network of Primary routes would consist predominantly of trunk roads and class I roads . Obviously it would be necessary, in process of selection, to consider whether certain roads should not be added or subtracted . It would also be necessary to keep the system under constant review so as to meet the changing needs of traffic.
138. Although it seemed to us desirable that Primary routes should in principle avoid city centres, it was also clear that this would be possible only in cases where complete ring or orbital roads exist. In the much more frequent case
where a town is by-passed on one side only, Primary routes must continue
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