Page:UK Traffic Signs Manual - Chapter 7 -The Design of Traffic Signs 2013.pdf/47

 The minimum vertical distance between the horizontal route arm and the forward legend above is 12sw for tiles and 14sw for panels, patches and symbols. The gap is larger for panels than for tiles, to take account of the 2 sw space between the letters and the bottom of the tiles. For simplicity, the minimum length of the forward arm should be taken as 12.5 sw. This gives 14sw between the horizontal route arm and any panel or patch above (12.5 sw route arm length plus 1.5sw gap from the route arm to the panel). Where tiles are placed directly on the route arm, the vertical distance will be 12.5sw rather than 12sw. However, some designs allow a line of legend to be placed alongside the vertical route arm. Diagram 2109 is a good example (see figure 5-8). In this case the minimum distance of 12sw between legend tiles and horizontal route arm should be used.

For the design of diagram 2004 illustrated in figure 5-7 the points to consider are:-

(a) "Biggleswick" and "Lampton" are two different blocks, being associated with different route numbers. As the "M11" patch is directly below the "A11" tiles, the appropriate block spacing of 2.5 sw is chosen, measured to the outside border of the patch.

(b) The width of the sign and the position of the vertical route arm are both determined by the left andright turn destinations.

(c) The longest ahead destination is centred horizontally over the vertical route arm and the other destination ranged left. (Note: all destinations associated with the same route are generally ranged left.) The centring rule applies only where there are side destinations both to the left and to the right (see para 5.7).

(d) As the “M11” patch is within 2.5 sw horizontally of the right hand edge of the vertical route arm, it is placed 1.5sw above the point of the arm. Had the patch been more than 2.5 sw from the arm, it would have been possible to have extended the arm to touch the tiles above. However, it would not have been possible to lower the legend block to touch the symbol (thus reducing the overall height of the sign) since the resulting gap between the "M11" patch and the horizontal route arm would then be less than 14sw.

(e) The pointed end of the right hand route arm will be two thirds along the "Axtley" panel, which is the longest destination associated with the right turn.

(f) The side turn route arms are both 4sw wide because they indicate numbered non-primary routes.

Figure 5-9 illustrates the design of the sign shown in diagram 2102. The additional design features to consider are :-

(a) The symbol for the through route is curved to reflect the alignment of the junction. This enables the inclined route arm to tuck into the legend block. The "Springwell, Foxley" block, with the route number "B470" repositioned alongside to the right, could have been placed over the route symbol, but this would have increased the overall height of the sign. 46