General layout and geometry - employment sites

Table 4 gives the general geometry for internal employment and commercial roads. Generally, both major industrial access roads and minor industrial roads are conventional cross-section roads with separated provision for vehicles and pedestrians, but their designs vary depending on likely levels of heavy-goods vehicles (HGVs).

Table 4: General geometry of employment and commercial roads
  Type of internal development road
Major industrial access road Minor industrial access road
Planning use class B2 and B8 E(g)(i), E(g)(ii), E(g)(iii)
Single-access development limit Normally no more than 8 hectares
85th percentile design speed 30mph 25mph
Shared surface No
Widths for two-way traffic Carriageway width: 7.3m Carriageway width: 6m for E(g)(i) [offices] ; 6.75m for E(g)(ii) and E(g)(iii)
Centre-line radius 55m minimum Defined by tracking
Crossfall 1:40
Longitudinal gradient

Minimum: 1:100 Maximum: 1:20

At junctions: not to exceed 1:30 for first 10m of the side road

Vertical curves See paragraph 3.28
Visibility distance at junctions, bends and vertical crests 70m 45m
Footways and cycleways Please refer to tables in the Active Travel Section of LHDG
Verges Grassed verges minimum 1m wide, minimum area 10sqm. Hard paving otherwise.
Steps Not normally acceptable in areas to be adopted as public highway unless a suitable alternative ramp is provided for those unable to climb steps

Planning use class

Other use classes, for example shopping and leisure, will be considered on a site-by-site basis and assessment will be dependent on the likely numbers of HGVs.

The council may recommend planning conditions to restrict change of use from E, B2 and B8 developments unless the roads – including construction specification –are designed to the major industrial road standard or the development layout provides for their future improvement at the developer’s expense.

Where a B1 development is large enough to generate significant numbers of HGVs, a major industrial road may be required. However, provision of a minor industrial access road may be acceptable for B2/B8 developments, such as business starter units, where they only generate a small number of HGVs traffic.

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