5.12 The minimum length of route arm is 12sw measured along the shortest side, as shown in figure 5-4 This does not apply to the side arm of the grade separated junction symbol, which has a minimum length of 24sw measured along the centre line (see figure 5-11).
DESIGN OF ROUTE SYMBOL STUBS
5.13 Where no destinations are indicated in a particular direction, a stub replaces the full length route arm. The length of the stub is generally equal to its width, which in turn will depend on the status of the route (see figure 5-1). Figure 5-5 details the dimensions of the stub and includes the relevant spacing to legend and border. See para 5.82 for the design of stubs which include the "no through road symbol.
UNRELATED BLOCKS
5.14 On a map type sign, destinations associated with different routes leading from a junction ahead are known as unrelated blocks. It is important that these blocks are properly positioned on the sign so that there is no confusion in associating each block with the correct route symbol.
5.15 Where one block is directly above another, the vertical space between them should be a minimum of 12sw. If the upper block is a panel or contains a patch or symbol on the bottom line, then the vertical space is increased to 14sw. This is to take account of the 2sw space at the bottom of a tiled legend (i.e. when the upper block is tiled, the actual space between the lower block and the bottom of the letters of the upper block, ignoring descenders, is 14sw).
5.16 Where two blocks are alongside each other, the horizontal space between them should be a minimum of 12sw for all types of legend.
5.17 Where a block is above and to one side of another block, it should be positioned as shown in figure 5-6.
DESIGN OF A MAP TYPE ADVANCE DIRECTION SIGN
5.18 The design of a complete map type sign is shown in figure 5-7, in the form of a working drawing for diagram 2004.
5.19 The base of the approach arm of the route symbol for all map type signs is 1.5sw from the bottom border. Where the approach arm is curved (e.g. junction on a bend), there should be a vertical section, with a minimum length equal to the width of the arm, before the start of the curve.
5.20 Where two route arms join, there is a fillet of 1sw radius.
5.21 The horizontal route arm extends to a point two thirds along the length of the legend block, as shown in figure 5-2. The measurement is always based on the longest block associated with a particular direction. Where a particular route has no associated destinations, the route arm is either replaced by a square ended stub that has a length equal to its width (see figure 5-5) or, if appropriate, shown as a "no through road" (see para 5.82).
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