DCAN 15: Vehicular Access Standards
Location of Accesses
7.1 Where a site is at the junction of two public roads (or private streets determined for adoption) the access should normally emerge onto the minor road (see Figure 4). This concentrates turning movements at a single point on the major road.
Fig 4: Location of Accesses Near a Junction
7.2 If a dwelling access is located near a junction, visitors might park their vehicles on the priority road and obstruct junction visibility. To reduce this risk, dwelling accesses should not normally join a priority road within the y-distance of a junction. However, as a relaxation on urban roads (subject to a 30 or 40 mph speed limit), dwelling accesses should not, as far as possible, join a priority road within the first 2/3 of the ydistance (see Figure 4). An alternative may be the provision of at least double the in-curtilage parking standard to give additional spaces for visitors off the priority road.
7.3 The spacing between a proposed major access (i.e. carrying over 250 vehicles per day) and existing junctions or major accesses must be considered. When the proposed and existing junction or access are on the same side of the road the spacing should preferably exceed 2/3 of the minimum forward sight distance given in Table B and must be at least 30m. When on opposite sides, the spacing should be sufficient to separate conflicting turning movements and avoid ‘straight across’vehicle movements. The spacing should normally be at least 15m and a right-left stagger is preferred (see Figure 5). There may be occasions when the layout of a major access will require a stagger spacing in accordance with TD 42 / 95 DMRB 4 Volume 6, and in excess of the minimum indicated in Figure 5.
Fig 5: Right / left junction stagger
7.4 On dual carriageway roads, it is important to keep crossing points to an absolute minimum to maintain safety, by confining traffic to public road junctions. Only in very exceptional circumstances will movements across the central reserve be permitted to and from an access. Crossingsof the central reserve shall not be provided on dual three lane carriageways and wider. These restrictions apply even when an access would otherwise be permitted under the main traffic routes policy contained in PPS3 1: “Development Control: Roads Considerations”.