4.55 The marking to diagram 1040.5 (figure 4-15) should be used to indicate the termination of the hard shoulder. The edge marking is always 200 mm wide, whether it is used on motorways or on all-purpose roads with full width hard shoulders. Both longitudinal lines may be formed by the marking to diagram 1012.2 or 1012.3 as appropriate. Where there are two terminations in quick succession, the hard shoulder between them should be hatched off to discourage its use, as rejoining the motorway from the isolated section is likely to be difficult.
END OF DUAL CARRIAGEWAY
4.56 When a dual carriageway road changes to a single carriageway road other than at a junction, traffic should be guided into the slower lane when leaving the dual carriageway section. Details of appropriate vertical signing can be found in figures 5-1 and 5-2 of Chapter 4.
4.57 The reduction in the number of lanes and the taper to a single carriageway should be achievedusing hatching to diagrams 1040 and 1040.4. The boundary is derived as follows (see figure 4-16):
(i)the traffic leaving the dual carriageway section should be reduced to a single lane by marking off the outside lane at the inclinations shown in table 4-6. The full reduction should be achieved no later than the end of the central reservation, although it may occur earlier,
(ii)from the point in line with the end of the central reservation, derived in (i), the boundary should continue to the centreline of the single carriageway section at a taper no sharper than that used in (i) above; if the dual carriageway section leads into a right hand bend, it might be betterto use a longer taper length in order to merge tangentially with the apex,
(iii)for the carriageway leading to the dual carriageway section, the boundary line should extend from the end of the taper in (ii) to the central reservation.
4.58 The lane line on the leaving carriageway (and the associated white road studs if used) should be omitted over the length of the taper, and two deflection arrows (diagram 1014) should be laid in the centre of the lane to be lost, in advance of the taper at the distances shown in table 4-6. The lane line between the start of the taper and the second arrow upstream of it should be replaced by a warning line to diagram 1004 or 1004.1 as appropriate (see paras 4.12 to 4.26).
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