Entrances to premises or private drives should be located at the ends of turning heads, in order to discourage parking. On type D, E and F roads, the size of the turning head should be determined by the expected type and frequency of vehicles manoeuvring.

Any cul-de-sac system off a type A or higher category road is to provide a turning head of not less than size 2 dimensions. This may be contained within the first road junction off the cul-de-sac. Where very large vehicles are likely to frequent the system, it may be necessary to incorporate a size 1 turning bay.

On type E, F and G roads that comprise side turnings from type D, E, F or G roads, and which are less than 20m in length excluding the turning head, a size 4 turning head may be used.

On type G roads of less than 20m in length, a size 5 turning head will be required. In all other circumstances, a size 3 turning head will be sufficient. This is adequate for turning fire and rescue tenders and pantechnicons. The shaded areas in the accompanying diagrams are required for vehicle overhang and must be included as part of the highway. These can form all or part of a footway, but should be adopted highway.

In situations where size 3-5 turning heads would normally be permitted, a turning loop incorporating car parking spaces may instead be used. It is not necessary to construct the turning head in the precise shape shown in these diagrams, or even to distinguish it by means of surface demarcation. It is simply necessary to demonstrate that the space provided is appropriately laid out to accommodate the size of vehicle consistent with the type of development. Turning heads can therefore be ‘disguised’ to avoid their becoming a dominant presence in a street.