3.1 Junction design and shared surfaces

3.1.1 Residential Streets

Within residential areas, traffic speeds should be physically constrained by localised narrowing of the carriageway, raised tables and chicanes. Priorities at junctions in these traffic calmed areas may be ambiguous, as long as a raised table across the whole junction brings attention to the various roads converging there. 

On other streets, and where Residential Streets meet General Access Streets more rigourous approach should be applied as detailed below.

3.1.2 Junction geometry

Where two roads intersect, a right angled T-junction should normally be formed with the major road, defined as that carrying the greater volume of traffic, continuous through the junction.

Generalised layout of a priority junction

Generalised layout of a priority junction

In general the geometric layout should clearly establish the priority of the major road to approaching drivers. We may additionally require that the appropriate road signs and/or markings are provided to emphasise this priority.

Junctions should be sited on level ground or in sags rather than at or near the crests of hills. Gradients should level out as they approach the junction.

Where possible, T-junctions on curves should be sited so that the minor road is on the outside of the curve.

Where two minor roads approach a major road from opposite sides, a staggered junction should normally be used instead of a crossroads. Right/left staggers (where minor road traffic crossing the major road first turns right out of the minor road, proceeds along the major road and then turns left) are preferred to left/right staggers.

Junction spacing (see table below) is related to the likely volumes and speeds of traffic and the distance required by moving vehicles to take up position between junctions for particular turning movements. The need to maintain road safety dictates the spacing and location of major access points.

Provision should be made at all road junctions for pedestrians to continue along the major road with a minimum of inconvenience, and therefore corner radii should be kept to the minimum required by the swept paths. Raised tables should be provided on pedestrian desire-lines, or dropped kerbs if this not practical. Appropriate tactile paving on main pedestrian desire lines is necessary.

Depending on the expected volume and speed of traffic, a Road Safety Audit of the junction may be required.

3.1.3 Visibility splays

At priority junctions there should be full visibility between points 1.05m above carriageway over the area defined in Figure 6. The X and Y distances are determined by the major road type and will be applied on this basis to junctions not specifically listed in the table below. Where, a minor road forms an up-hill approach to the major road, care should be taken to ensure that objects within the visibility triangle do not interfere with sight-lines. Reference should be made to CD123 of the Design Manual for Roads and Bridges.

Table 1: Dimensions for priority junctions on roads with speed limit of 30mph or lower:

Major road type

Minor road type

Minimum spacing on major road 

Visibility splay

Corner radius

X

Y

R

Main Distributor Road

Non-residential Street

 

Desirable = 100m

Absolute = 40m

9m

90m

10.5m

(Seek advice of Roads Authority where long vehicles are anticipated)

Main Distributor Road

General Access Street

Desirable = 100m

Absolute = 40m

4.5m

90m

10.5m

Non-residential Street

Non-residential Street

40m

4.5m

70m

9.0m

General Access Street

General Access Street

40m

4.5m

70m

7.5m

General Access Street

Residential Street

40m

4.5m

70m

6.0m (or demonstrate using swept paths)

Residential Street

Residential Street or driveway

40m

2m

20m

No minimum – check swept paths

The dimensions given in the table above, apply only where there is a speed limit of 30mph or less. Where speeds are higher, and particularly in rural areas, apply the advice from CD123 of the Design Manual for Roads and Bridges. In all cases, specific details can be discused with the Roads Authority and exceptions agreed. 

Table 2: Visibility distances on roads with speed limit greater than 30mph

Design speed of major road 

Visibility splay from minor road

X distance

Y distance

50kph

Desirable = 9m

Absolute = 4.5m

70m

60kph

Desirable = 9m

Absolute = 4.5m

90m

70kph

Desirable = 9m

Absolute = 4.5m

120m

85kph

Desirable = 9m

Absolute = 4.5m

160m

100kph

Desirable = 9m

Absolute = 4.5m

215m

The radii for corners will be determined by which vehicles use the junction regularly. These should be able to turn without obstructing oncoming traffic although some larger vehicles may need to use the full width of road. Refer to paragraph 2.5 in CD 109 - Highway link design (standardsforhighways.co.uk) for the relationship between design speeds and speed limits.

No frontage access or lay-by parking will normally be permitted in the immediate vicinity of a road junction;or where parked vehicles would interfere with junction sightlines.

3.1.4 Shared surfaces

Shared surfaces and level footways are not encouraged in residential areas because, unless there is a high volume of pedestrian activity, traffic speeds may increase.

Shared surfaces may be adopted only where it can be demonstrated that

  • traffic speeds will be physically constrained to less than 10mph; and
  • the space will not fill up with parked cars

Our guidance on shared surfaces is currently under review and may be updated shortly.

A further point to note if considering shared surfaces is that the Occupancy Certificate may not for issued for a dwelling unless the road surface is complete. This is to ensure accessiblity to the premises.

3.1.5 Transitions to shared surfaces

(A)

Diagram showing transition from 5.5m carriageway to 3.7m wide shared surface

Transition from 5.5m carriageway to 3.7m wide shared surface

(B)

Diagram showing transition from 5.5m wide carriageway to 5.5m wide shared surface

Transition from 5.5m wide carriageway to 5.5m wide shared surface

 

(C)

 

Diagram of transition with narrowing from 5.5m wide carriageway to 5.5m wide shared surface

Transition with narrowing from 5.5m wide carriageway to 5.5m wide shared surface


Note: These webpages are for reference by developers of housing and employment sites in East Lothian. 
They provide guidance on transport infrastructure against which Planning Applications will be assessed 
and evaluated, and set out East Lothian Council's procedures regarding the construction and adoption of 
new roads in accordance with current legislation. 
These pages supersede all previous versions of our Standards for Development Roads document. 

Revisions 
01/07/2023 Document release