An inspector has authorised shorter visibility splays than deemed necessary by the council at the access to six dwellings in Suffolk, finding no particular justification for insisting on visibility splays suitable for a trunk road (DCS Number 400-022-073).

The highway authority sought visibility splays into the site to be provided in accordance with the Design Manual for Roads and Bridges (DMRB), and so sought splays of 2.4m x 90m rather than the 2.4m x 43m shown in the submitted drawings. The appellant, on the other hand, contended that the requirements for visibility splays set out in Manual for Streets should be used since the road had a 30mph speed limit. 

The inspector reasoned that it was necessary to consider what visibility splays were suitable. The DMRB states in Section 1, he recorded, that it shall be applied to the appraisal and design of motorways and trunk roads. He noted that the road was not a trunk road (or motorway). He accepted that the highway authority could apply the standards within the DRMB to other roads, but given the wording of the DRMB he found it axiomatic that there must be sound reasons for doing so.

The council argued that the road was free flowing with little built form, and had a very rural feel. The inspector observed, however, that the road had a 30mph speed limit and was on the edge of the village, with housing and a roundabout close by. He considered that it very much had an appearance of a road entering or leaving a built-up area, rather than an open, rural road. He therefore could not see any particular justification for insisting on visibility splays suitable for a trunk road, as set out in the DMRB. 

Allowing the appeal, he was satisfied that the provision of visibility splays of 2.4m x 43m would provide safe access and egress from the site.

Section 4.1515 of DCP Online concerns the safeguarding of traffic safety at accesses.