92. We recommend that the sign at figure 45 should be used at the top of dangerous hills when the gradient is 1 in 10 or steeper. On very steep hills or on long steep hills where an additional warning is essential the sign should be supplemented at appropriate points on the hill by the plates at figures 45a, b and c. We recommend also that the sign at figure 45 be used at the foot of gradients which are likely to cause trouble to ascending drivers. It seems to us unnecessary that the plates at figures 45a, b and c should require Ministerial approval in each case, as at present, before they are erected.
Narrow bridge (Regs. 120)
93. Both these hazards should be indicated by the sign shown in figure 41 .
94. There is no Protocol equivalent for this sign and since trams have now been largely abandoned, we recommend that no warning sign for this hazard be prescribed. Where signs still exist their retention for so long as they are needed should be authorised.
Single track road (Regs. 123)
95. There are no Protocol equivalents for these. We recommend that the Road narrows sign (figure 41) be used, supplemented by the plate shown at figure 41a or figure 41b.
96. There is no warning sign in the Protocol specifically for a hump bridge. We think one is necessary and recommend the design at figure 46. This sign should be supplemented by a warning line on the carriageway but if the road over the bridge is more than 18 feet wide and the Departments' criteria for the use of double white lines are met they should be used.
1½ m. ahead. Low bridge headroom 14′ 0″ (Regs. 126)
440 yards (arrow to the left) low bridge headroom 14′ 0″ (Regs. 127)
97. Height and width restrictions are commonly indicated on the Continent by prohibitory rather than warning signs, but the Protocol permits limitation of height and width to be indicated within a warning triangle and we therefore advocated the use of the sign at figure 64. Where it is necessary to show the distance to the bridge and the direction in which it lies the plates at figures 71 , 72 or 73 should be added below the sign.
98. A similar sign (figure 64) should be attached to the bridge itself and a chord marking (figure 64a) incorporated to give the warning conveyed by the sign prescribed at Regs. 128.
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