New Roads and Street Works Act 1991: Code of Practice for the Co-ordination of Works in Roads

Chapter 4 Roads Subject to Special Controls

4.1 General

4.1.1 NRSWA enables certain categories of road to be designated as being subject to special controls. These are:

  • protected roads;
  • roads with special engineering difficulties; and
  • traffic sensitive roads.

4.2 Protected Roads


4.2.1 By virtue of section 120 of NRSWA, all special roads within the meaning of the Roads (Scotland) Act 1984 (e.g. motorways) are protected roads. In addition, a road works authority may designate other roads as protected roads providing the requirements as specified in the Regulations are met.

4.2.2 Roads, other than special roads, may also be designated as protected only if they:

(i) serve or will serve a specific strategic traffic need;

(ii) are subject to such high and constant traffic flows that designation as traffic sensitive would not be sufficient to avoid serious disruption to traffic caused by road works; and

(iii) there is a reasonable alternative route in which undertakers can place their apparatus which would otherwise have been placed lawfully in the protected road.

The Implications of Designation

4.2.3 Undertakers should give the same notice for protected roads as those applicable to traffic sensitive roads.

4.2.4 Once a road has been designated as protected, the activities of undertakers and road works authorities will be severely restricted.

4.2.5 Undertaker's apparatus may not be placed in the road (except by way of renewal) without the consent of the road works authority, although under NRSWA, lateral road crossings should normally be allowed. However, if it is allowed with conditions attached, the road works authority may contribute to the undertaker's expenses in complying with those conditions where the undertaker is involved in additional expense.

4.2.6 Road works authorities may charge a reasonable fee to cover expenses incurred by them in relation to consents.

4.2.7 Undertakers' works in verges and central reservations not encroaching on the carriageway should normally be allowed. Road maintenance or repairs will, in general, be carried out at night or, where appropriate, at weekends, or at other times when the impact upon traffic will be kept to a minimum. However, working at night may cause conflict with environmental health legislation.

Existing Roads - Designation as a Protected Road

4.2.8 Given the possible financial implications for both road works authorities and undertakers, designation should be contemplated only when essential. The decision to designate should be taken only after consultation and after other means of reducing delay and inconvenience caused by road works have been explored.

4.2.9 The road works authority must justify the need for designation and:

(i) take into account the needs of undertakers both to supply and maintain services to frontagers and the use of such roads for existing primary supply routes; and

(ii) reimburse all reasonable expenses incurred by the undertaker if removal or alteration of apparatus in the road is required (subject to appropriate allowances for betterment, deferment of renewal and value of recovered apparatus). The cost sharing arrangements for diversionary works will not apply.

New Roads - The Implication of Designation

4.2.10 Where construction of a road is planned and is being considered for designation, the road works authority shall consult with all undertakers who might have a vested interest and others, such as transport, bridge, and sewer authorities, as well as adjacent landowners and frontagers who might have an interest. The road works authority will, where requested and where reasonably practicable, make provision at the undertaker's expense for furnishing the requisite service areas or service strips alongside the carriageway and for supplying duct or service crossings.

4.3 Roads with Special Engineering Difficulties


4.3.1 Under Section 122 and Schedule 6 of NRSWA, the term 'special engineering difficulties' relates to roads or, more commonly, parts of roads, associated with structures, or roads of unusual construction where works must be carefully planned and executed in order to avoid damage to, or failure of, the road structure with associated danger to persons or properties.

4.3.2 Plans and sections of any works proposed must therefore be approved by any authority with an interest in the structure, i.e. the road works authority, sewer, transport or bridge authority. This enables the authority concerned with the structure to satisfy itself that no detrimental effect will result from any proposed road works.

Scope of Designations

4.3.3 The designation of roads with special engineering difficulties should be used only where strictly necessary, bearing in mind the safeguards already provided elsewhere in NRSWA e.g. sections 128 (for other apparatus in the road), 147 and 148 (for bridges and sewers), and 152 (level crossings and tramways). This is in the interests of all concerned (e.g. road works authorities, undertakers and, where appropriate, the owner of the structure involved).

Circumstances where Designation may be Appropriate

4.3.4 (i) Bridges. The road may be designated if the bridge authority is concerned about the influence of road works on the strength, stability and waterproofing of the bridge, or access for maintenance or for any other purpose. In general, the designation would relate to the whole of the bridge structure, but it will only be necessary to designate the area adjacent to the bridge and not the whole length of the road. Three areas may be designated:

  • the bridge deck;
  • an area in the vicinity of the abutments where the excavation is no deeper than 1.2 metres; and
  • where further restrictions are required if excavation is greater than 1.2 metres deep.

(ii) Retaining walls. Retaining walls may be designated where they give support to the road and bridge abutments and where the foundations are sufficiently shallow to cause concern that any excavations would adversely affect the integrity of the structure. Where the foundations are piled, designation is only likely to be necessary if the excavation could alter the degree of support given to the piles by the soil.

In many cases, it will only be necessary to designate the area adjacent to the structure concerned and not the whole width of the road. Two areas may be designated:

  • where excavations are no deeper than 1.2 metres, and
  • where further restrictions will be required if an excavation is deeper than 1.2 metres.

(iii) Cuttings and Embankments. Areas adjacent to such structures should be designated if excavation could lead to slides or slips of the soil, or where excavation could affect special construction features such as earth reinforcement systems or lightweight fills. The whole width of road may be designated, or specific areas similar to those in (b) above.

(iv) Isolated Structures. Examples of isolated structures include high mast lighting columns and large sign gantry supports. Where excavation could affect their stability, areas immediately around the supports should be designated, again distinguishing between excavations up to 1.2 metres deep and those that are deeper than 1.2 metres.

(v) Subways and Tunnels at Shallow Depth. Areas immediately above the subway/tunnel and adjacent areas may be designated.

(vi) Tramway Tracks in the Road. Areas occupied by the tracks and immediately adjacent areas may be designated. Additional protection to the appropriate authority is also given in Section 152 of NRSWA. See also paragraph 11.7.

(vii) Culverts. The area of the road immediately above a culvert may be designated where works could adversely affect structural integrity. Accordingly, a reinforced concrete pipe or box culvert would not justify designation but a masonry or steel culvert could be considered if the depth of cover is shallow.

(viii) Undertakers' Apparatus. Designation is required only in exceptional circumstances, such as:

  • electricity pylons adjacent to the road; or
  • the presence of critical operational apparatus, for example communications or signalling cables for transport operators like Network Rail; or
  • apparatus at shallow depths particularly when within the bound layers.

In most cases the need for safety and security of apparatus is adequately covered by the requirements of Sections 128 or 148 of NRSWA.

(ix) Pipelines. Some types of pipeline installed under the Pipelines Act 1962, and similar structures which traverse the road, may justify designation.

(x) Engineering Problems. Roads that pose extraordinary engineering problems in the event of excavation taking place may be designated e.g. a road of weak construction founded on very poor soil such as a peat bog, which might have utilised geotextiles.

Practical Considerations

4.3.5 Designations should not be made as a matter of policy wherever there is a bridge or structure likely to be affected by road works. Each case should be considered on its merits. Road works authorities and owners of structures should re-examine the designations concerned with a view to withdrawing any that are unnecessary in the light of the other safeguards included in NRSWA or other legislation.


4.3.6 It is not practical for the road works authority to identify all cellars under footways and carriageways to decide whether they justify designation.

4.3.7 Under section 56 of the Roads (Scotland) Act 1984, owners of cellars wishing to carry out works are required to notify the roads authority and those undertakers identified by the roads authority as being affected by the works.

4.3.8 Road works authorities and undertakers wishing to carry out work in areas where they know, or might reasonably be expected to know, of the existence of cellars, should notify the cellar owners or frontagers when they intend to carry out excavations close to cellars or extensive excavations which will impinge upon any cellars.

Policy Guidance

4.3.9 The responsibility for the designation of sections of roads with special engineering difficulties lies with the road works authority, who is also responsible for maintaining such designations within SRWR. It is important to appreciate that:

(i) the owner of the structure informs the road works authority of the existence of the structure so that it can be considered for designation; and

(ii) the key relationship, in terms of ensuring that adequate precautions are taken, is that between the works promoter and the owner of the structure concerned.

4.3.10 If this mechanism is to work effectively, it is essential that:

(i) there is close co-operation and consultation between the road works authority, undertakers, bridge authorities and other owners of relevant structures in relation to the designation and withdrawal of designation of sections of roads with special engineering difficulties;

(ii) arrangements are agreed between works promoters and the owners of structures on the handling of emergency and urgent works on sections of roads with special engineering difficulties;

(iii) in the cases of planned major works and the provision of new supplies, there are early discussions between works promoters and the owners of the structures concerned; and

(iv) on receipt of formal notices covering works on sections of road with special engineering difficulties, the road works authority ensures that the necessary actions are in hand.

Works not Requiring Plans and Sections

4.3.11 Road works that can be undertaken either without breaking up or opening the road, or by making use of existing manholes, cannot endanger the integrity of the road or structure that the designation was intended to protect. Accordingly:

(i) no plans and section are required in respect of any of the following works:

  • those not involving any breaking up or opening of the road;
  • small works in manholes and surface boxes, such as cable repairs, meter replacements and valve operations;
  • pole, lamp, column and sign replacement in situ;
  • pole testing;
  • resetting frames and covers;
  • resurfacing areas up to 20 square metres; and
  • remedial works to restore reinstatement to specification.

(ii) however, road works involving the insertion or extraction of cables or ducts from existing manholes should be notified, but a description of the works will be sufficient and the relevant authorities' response, if any, should be made within 3 days; and

(iii) road works to a service pipe or line in a bridge where the apparatus is in preformed pipe or cable bays, and can be reached by removal of the paving or loose fill, will also require only a description of the road works; in this case, the relevant authorities will have 7 days within which to respond.

Works Requiring Plans and Sections

4.3.12 The following principles apply where road works involve breaking up a road and require plans and sections:

(i) To facilitate interpretation of plans and sections, details of the civil engineering design, requirements and method of construction and implementation of the road works should, where appropriate, be submitted to the relevant authority. It is therefore essential that the authority is informed of proposed road works as far in advance as is possible, to allow the effect on the existing structure to be determined. This should be accomplished by informal exploratory discussion in addition to normal co-ordination meetings.

(ii) When exploratory discussions show that little if any alteration is required to the structure concerned, a plan and section should be submitted to the relevant authority. If the road works relate only to a service pipe or service line, in each case of less than 100 metres in length, or overhead electric or telecommunications lines, the submission need allow only 7 working days for response. Otherwise the submission must allow one month for approval or disapproval.

(iii) Where it is clear that more than minimal alteration to the structure will be needed, plans and sections should be submitted in good time to allow for adequate consideration of the proposed road works and the protective measures or alterations that must be made to the structure concerned, and the appropriate response (approval or otherwise) from the relevant authority.

4.3.13 Where a road has been designated because of an undertaker's apparatus or a hazardous pipeline which is fundamental to the structure and integrity of the road, or is particularly sensitive to the risk of damage by road works, the road works authority must consult that undertaker when plans and sections of proposed road works are submitted. The authority must not approve any proposals except in accordance with the specified requirements of that undertaker and in cases of dispute between undertakers this shall be resolved in accordance with the Code of Practice for Dispute Resolution and Appeals.

4.3.14 The undertaker promoting the road works should afford the relevant authority all reasonable facilities for inspecting or monitoring the execution of the road works. The extent of the support needed will depend on the scale and nature of the road works.

4.3.15 In the case of minor works, an inspection to ensure that the structure remains undamaged will be sufficient.

4.3.16 Extensive road works, or any underground road works immediately adjacent to the structure concerned, can involve monitoring the excavation, installation and maintenance of supporting works or structures and the backfilling of excavations.

4.3.17 The undertaker promoting the road works will be responsible for the reasonable costs of taking measures to protect the relevant structure.

4.3.18 Where the road works authority is legally entitled to recover its reasonable costs and it is necessary to monitor the road works, the undertaker must meet the reasonable monitoring costs. Should the undertaker dispute the need for monitoring in whole or in part, to save delay monitoring must take place and the undertaker advised of costs incurred. The dispute must be settled subsequently.

4.4 Traffic Sensitive Roads


4.4.1 Under section 123 of NRSWA, a road works authority may designate certain roads (or parts of roads) as "traffic sensitive". The criteria under which such designations are to be made are specified in The Road Works (Scottish Road Works Register, Notices, Directions and Designations) (Scotland) Regulations.

4.4.2 It is expected that these criteria will cater for the majority of cases. Road works authorities will therefore normally apply them as a matter of course. However, to cater for very special local circumstances, such as individual annual or seasonal events, or where the existence of the criteria has not been established but there is a danger of serious disruption to traffic, provision is made for additional designations of traffic sensitivity by agreement between road works authorities and local undertakers. Therefore, this type of designation can only be made by agreement with the majority of local undertakers.

4.4.3 Designations may apply to the whole, or parts of, the carriageway, verge, footway or pedestrian area, and to:

  • certain times of the day;
  • days of the week; or
  • days of the year.
    depending on circumstances.

4.4.4 The traffic sensitivity designation will also apply to the first 50 metres or complete length, whichever is shorter, of an adjoining road that has a junction with that traffic sensitive road where temporary traffic control is deployed on the traffic sensitive road. Road works authorities must ensure that these additional lengths of road are clearly designated within the Associated Street Data sets in the SRWR.

4.4.5 Once a designation is made, it applies to all works taking place in the road. Road works authorities carrying out works for road purposes, as well as undertakers carrying out road works, must avoid carrying out those works in traffic sensitive situations at traffic sensitive times unless there is no alternative.

4.4.6 Works promoters should clearly understand that shorter notice periods for works in traffic sensitive roads are only permissible for works that take place outside sensitive times. Where road works are planned to take place in a traffic sensitive road, outside traffic sensitive times and as a consequence, a shorter notice period, or no notice is given, it is essential that the road works are suspended during the traffic sensitive period. Full, unimpeded traffic flow must be provided during the traffic sensitive period, if necessary by temporarily backfilling excavations or using road plates.

Vehicular Routes

4.4.7 Provided they meet the statutory criteria, traffic sensitive routes may include:

(i) main inter-urban roads and main radial and other commuter routes (many routes near town and city centres) which carry heavy peak traffic flows;

(ii) heavily trafficked routes into and within holiday areas during the holiday/visitor season;

(iii) routes that are only traffic sensitive on certain predetermined occasions e.g. race meetings, county shows etc; and

(iv) locations adjacent to schools.

Pedestrian Areas

4.4.8 Subject to meeting the criteria these may include:

(i) commuter routes - footways very heavily used at peak times by commuters;

(ii) special events pedestrian routes - pedestrian routes to special events, e.g. the local showground, football ground etc., which are only sensitive on certain days of the week; and

(iii) pedestrian shopping areas - often areas of special paving, with restricted access for delivery vehicles.

4.5 Procedure for Making Designations

4.5.1 The procedure for making designations is set out in Schedule 2 of the Road Works (Scottish Road Works Register, Notices, Direction and Designation) (Scotland) Regulations.

4.5.2 Before making a designation of a road, the road works authority shall give notice of their intention, specifying a time, not less then one month, within which objection may be made to:

(i) every undertaker which the authority know to have apparatus in any road to which the proposed designation refers or which has given notice under section 113 of their intention to execute road works in the road;

(ii) every local authority (other than the road works authority) in whose area any road to which the proposed designation relates is situated;

(iii) any person who has requested the road works authority in writing to be given notice of a proposed designation; and for protected roads only

(iv) the owners or reputed owners, and the occupiers or reputed occupiers of any land which is adjacent to the road.

4.5.3. For roads with special engineering difficulty and traffic sensitive roads the notice must also be published within one or more newspapers circulating in the locality.

4.5.4 If within the specified period no objection is received by the road works authority, or if all objections have been withdrawn, that authority may make the designation.

4.5.5 If within that period an objection is received by the road works authority from any person on whom notice is required to be served or from any other person appearing to the road works authority to be affected by the proposed designation and the objection is not withdrawn, the road works authority shall before making the designation:

  • in the case of roads with special engineering difficulty or traffic sensitive roads, consider the objection and may make the designation, with or without modifications, or may decide not to make the designation, as they think fit; and
  • in the case of a protected road, hold a local inquiry. Where a local inquiry has been held the road works authority shall consider the objections and the report of the person who held the inquiry and may make the designation, with or without modifications, or may decide not to make the designation, as they think fit.

4.6 Procedure for Withdrawing Designations

4.6.1 A road works authority may at any time withdraw the designation of a road as a protected road and the designation of a road as traffic sensitive.

4.6.2 A road works authority may at any time withdraw the designation of a road as a road with special engineering difficulties. However this shall not occur without prior consultation with the transport authority or undertaker at whose request the designation was made, or without the consent of the Scottish Ministers where the designation was made in pursuance of a direction by them.

4.6.3 If a road works authority withdraws a designation of a road as a protected road they shall publish a notice in one or more newspapers circulating in the locality in which the road to which the withdrawn designation related.

4.6.4 The road works authority must record the detail of all designations and withdrawals by using the Associated Street Data in the SRWR (see Chapter 3).

4.7 Other Features of the Road


4.7.1 There are a number of other features of a road that may either:

  • impact upon the planning and co-ordination of road works; or
  • be subject to restrictions imposed by legislation other than NRSWA.

To facilitate best practice, information about such features may be held as an Associated Data record in the SRWR. Such data may be provided by the relevant roads authority or body responsible for the designation (see also RAUC(S) Advice Note 5). Data capture codes have been defined for the following types of feature:

Environmentally Sensitive Areas

4.7.2 These will include such areas as Sites of Special Scientific Interest and Ancient Monuments. The Special Designation Description will indicate the type of sensitive area.

Structures (not Designated as Being of Special Engineering Difficulty)

4.7.3 There are various structures associated with the road which, whilst not fully meeting the criteria for designation as being of Special Engineering Difficulty, nevertheless warrant extra care being taken when working in their vicinity. The Special Designation Description will indicate the type of structure.

Special Surfaces

4.7.4 These include, but are not restricted to, such surfaces as porous asphalt, tactile and coloured surfaces. The Special Designation Description will include the type of surface.


4.7.5 Government and oil or gas pipelines laid under the Pipelines Act 1962.

Priority Lanes

4.7.6 These include cycle routes and bus lanes. The Special Designation Description will indicate the type of priority lane.

Level Crossing Precautionary Areas

4.7.7 The Special Designation Description will indicate the extent of the Precautionary Area. When works are proposed within the Precautionary Area, the procedures applied in Appendix C of this Code must be followed.

Special Construction Needs

4.7.8 The Special Designation Description will indicate the extent and type of special construction and could include such sites as geotextile mats and areas where sulphate resistant concrete is required.

Parking Bays and Restrictions

4.7.9 The Special Designation Description indicates roads with parking meters, residents' parking bays, parking restrictions such as red routes and other permanent restrictions. This will alert works promoters to plan any necessary action such as applying to the local authority to have parking suspended.

Pedestrian Crossings and Traffic Signals

4.7.10 The Special Designation Description indicates roads which have signal-controlled pedestrian crossings and permanent traffic signals.

Speed Limits

4.7.11 The Special Designation Description indicates the speed limit appropriate to the road.

Transport Authority Critical Apparatus

4.7.12 This is apparatus used, or owned, by a Transport Authority that is critical to the operations of the Transport Authority and if damaged or interrupted could disrupt or temporarily stop services; for instance damage to high voltage cables supplying power to a rail network would cause its closure and severe inconvenience to the passengers.

Other Situations Meriting Special Consideration

4.7.13 Designation of traffic sensitive situations is intended to apply to locations where serious traffic disruption may ensue from the presence of road works or works for road purposes. There are, however, a number of situations for which designation as traffic sensitive is not appropriate but where special care needs to be exercised when works in roads are to be carried out.

Situations which might merit special attention (but which would not otherwise satisfy the requirements for traffic sensitivity) include:

(i) access to busy bus or railway stations;

(ii) works at major bus stands on the road;

(iii) road works near to the vehicular access to fire stations, ambulance stations, police stations and hospitals;

(iv) footway works impacting on people with visual or other disabilities;

(v) sites of accident concentration; and

(vi) sites at school crossing patrols.

It would be appropriate to identify and discuss such situations at local co-ordination meetings with a view to agreeing means of minimising the occurrence of problems on site.