This document is published by National Highways.

This document forms part of the works specification. It does not purport to include all the necessary provisions of a contract. Users are responsible for applying all appropriate documents applicable to their contract.

This standard is introduced as part of an objective to support the adoption of new guidance and best practice into application as quickly as possible. This will supplement Traffic Signs Manual Chapter 8 TSM Chapter 8 [Ref 3.I], which will continue to retain the majority of guidance and best practice relating to road works and temporary situations.

The Traffic Signs Manual chapters are subject to cyclical updates, around every three to four years at present, therefore leaving a significant period of time between publications. Currently there are limited other opportunities to disseminate new guidance and best practice relating to road works and temporary situations into industry for consideration.

This standard will ensure that industry, customers and stakeholders will be facilitated to realise the benefits of new practice and guidance more efficiently. The content will largely be located within the appendix of this standard, as it will be the decision of temporary traffic management (TTM) designers and schemes as to when it is incorporated into their works, in line with current working practices. However, it should better support the industry in making decisions relating to the design and operation of TTM given the continued updates to guidance through this mechanism.

It is envisaged that content situated in this standard will transfer into future iterations of TSM Chapter 8 [Ref 3.I]where applicable. This will be determined via existing governance and procedures and would need to be consented to by the devolved administrations and other identified stakeholders.

The assumptions made in GG 101 [Ref 4.N] apply to this document.

1.1 The requirements in this document shall be used for the design and operation of temporary traffic management (TTM) and road works on motorways and all-purpose trunk roads.

1.2 This document shall be implemented forthwith for the design of road works and the operation of TTM on all highway schemes on the Overseeing Organisation's motorway and all-purpose trunk roads according to the implementation requirements of GG 101 [Ref 4.N].

1.3 The requirements contained in GG 101 [Ref 4.N] shall be followed in respect of activities covered by this document.

2.1 Road works and temporary traffic management (TTM) shall be designed and operated to be both safe and efficient.

NOTE The principles of "safe and efficient" traffic management are outlined in the Traffic Signs Manual TSM Chapter 8 [Ref 3.I].

2.1.1 In addition to TSM Chapter 8 [Ref 3.I], DMRB standards and other relevant publications, road works may be designed and operated in line with the additional guidance detailed in the appendices of this core document.

2.1.2 Additional guidance detailed in the appendices of this core document may be used when designing and planning the operation of TTM.

2.2 All relevant, available guidance and standards relating to TTM design and operation shall be assessed when designing road works or temporary situations, as this will help support safe systems of working.

NOTE 1 TTM design and operations are underpinned by recognised training courses and qualifications relevant to the activity selected.

NOTE 2 It is for the TTM designer to adopt, adapt or develop the road works design and/or TTM operational practices to suit the actual site conditions.

2.3 Road works shall be designed on a site-specific basis.

2.4 Safe systems of work, including safety risk assessments, design review and design approval shall be developed and followed in the design of TTM.

2.5 The level of safety risk management for road works design and TTM operations shall be determined and informed by a safety risk assessment.

2.6 When designing, operating and planning road works the safety of road workers, road users and all populations affected directly or indirectly by the works shall be clearly demonstrated.

NOTE “Populations” are defined in GG 104 [Ref 5.N], with additional guidance provided in Traffic Signs Manual TSM Chapter 8 [Ref 3.I].

2.7 The risk to road workers must be managed in accordance with the requirements of the Health and Safety at Work etc Act UKPGA 1974/37 [Ref 3.N]and, where applicable, the Health and Safety at Work (NI) Order 1978 NIOC 1978/1039 [Ref 2.N].

NOTE Safe design and operations can be demonstrated via documentation such as safety risk assessments and safe systems of works.

2.8 Road works shall be designed using the principles of ALARP when assessing risk.

Traffic Signs Manual TSM Chapter 8 [Ref 3.I]provides guidance for those responsible for the design and operation of temporary traffic management (TTM). It is expected that those persons looking to utilise the enhanced mobile carriageway closure (EMCC) outlined within this document are suitably trained and possess the relevant qualifications to adopt this technique. They should also be both experienced and familiar with the principles of TSM Chapter 8 [Ref 3.I] and TTM.

On dual carriageway roads, including motorways, some traffic management tasks and works operations may need to be conducted on the carriageway using a temporary traffic free zone (TFZ), where the road is clear of passing traffic for a short period of time. The installation or movement of a short length of coning and signing to change the configuration of a TTM layout during road works, which takes less than 5 minutes, is one such example where this may be required.

The mobile carriageway closure (MCC) and the convoy control vehicle technique are existing and established techniques with guidance outlined in TSM Chapter 8 [Ref 3.I]. They are operated by the traffic Authority or contractor using signs to provide warnings and information relating to restrictions or changes in carriageway conditions. The traffic signs used as part of these techniques are done so by the powers provided by Sections 64/65 of the Road Traffic Regulation Act 1984 UKPGA 1984/27 [Ref 6.N]. EMCC signs require authorisation for each highways/road Authority they are used on. At the time of publication the only authorisation is for National Highways’ roads. For their use on other Overseeing Organisation’s roads one should check with the relevant national body responsible for signs authorisations.

The EMCC, as described in this document, is a development of both the aforementioned techniques. Whilst the EMCC includes the word "closure" its use does not include planned closures of the carriageway by bringing traffic to a stop (see Section A2).

The implementation and selection of any technique for an operation should be considered and evaluated as part of the planning phases. Both contractors and the Authority should be aware that the EMCC is to be considered as a potential method of working alongside other existing and established TTM techniques.

It is essential that the use of the EMCC technique does not transfer risk from road workers to road users. The principles of ALARP need to be adhered to as outlined in TSM Chapter 8 [Ref 3.I].

Temporary traffic free zones have traditionally been created by requesting police or traffic officer support to implement a rolling road block. With the emergence of the EMCC, requests for police or traffic officers to support planned work activities should begin to be limited to unplanned incidents.

The traffic free zone created by the EMCC allows for traffic management operations to be conducted in a sterile area. EMCC can be used for the installation, maintenance, switching or removal of any temporary traffic management layout and pre-setting of equipment. It can also be used to support the maintenance of a traffic management system such as when live lane working is required for crossing a carriageway to maintain traffic management equipment, managing displaced traffic management equipment and retrieving debris, all of which are expected activities occurring as part of planned works.

The EMCC technique can be used for short-term works operations to avoid a planned total closure of the carriageway. This technique may be useful for the installation of TTM exit slip road detail, as it eliminates the need for a temporary short term exit slip road closure.

The EMCC technique described in this document may be suitable for use on dual carriageways and motorways with up to four lanes. Where used on four lane carriageways up to a maximum of one additional lane from a junction (e.g. a parallel merge) can be incorporated. This technique may also be used on slip or link roads where safe and practicable to do so.

This document does not distinguish between the differing features of a carriageway such as a 'controlled motorway', 'dynamic hard shoulder' or 'all lane running'. These characteristics need to be assessed at the design and planning stage of the works, along with any risk mitigations based on the site.

In general, the duration required to create the sterile area should be planned to generally remain in the 5-to-7-minute range, and should not exceed 9 minutes, before the EMCC vehicle starts to accelerate from 10 mph to release traffic back to free flow conditions.

At an average speed of 10 mph the EMCC vehicle and traffic behind it will cover around 300 m every minute. The distance upstream, and therefore the traffic free zone, needs to be identified based on;

Maintaining a minimum longitudinal safety zone of 200 m between the working area and the EMCC was shown in the trials to support a safe system of working, although a safety risk assessment should determine the required distance.

A traffic sign arrangement consisting of signs to Diagram 584 and Diagram 7003.1 UKSI 2016/362 (TSRGD) [Ref 7.N] (see Section A6) need to be erected upstream of the EMCC start point on all approach carriageways including slip and link roads when using the technique (see Figure A.5).

The presence of features such as entry slip roads or lane gain/drops within the traffic free zone between the working area and EMCC start point should be identified, and traffic control measures implemented. This can include a slip road closure, or additional EMCC vehicles being provided and coordinated to merge to continue downstream of an entry point (Figure A.6). TSM Chapter 8 [Ref 3.I] provides further detail and guidance on closing access junctions as part of TTM operations.

The EMCC vehicle may straddle lanes when creating a traffic free zone as the red 'X’ of the upper panel is not lane specific. (Figure A.7)

Table A.1 Minimum numbers of EMCC vehicles

Number of lanes	Minimum number of EMCC vehicles
2 lanes	1
3 lanes	1
4 lanes	2

The minimum number of EMCC vehicle(s) used needs to comply with Table A.1.

When undertaking an EMCC operation the operator of the EMCC vehicle needs to be a competent, qualified individual and they will have completed a recognised training course in the use and operation of the EMCC. It is essential that regular monitoring of EMCC operator performance occurs.

As with all work instructions and operations taking place on a live carriageway a briefing and equipment testing takes place before the event. Briefing and testing on the EMCC will normally include items such as communication protocols and time constraints, the incursion warning system and two-way radio equipment prior to use. This needs to be covered as part of the risk assessment for the operation.

Where an EMCC vehicle is not used as part of an EMCC operation, such as for welfare facilities only, the operator is not required to have completed the EMCC training.

This section contains the signs which have been authorised for use in connection with the EMCC technique on National Highways roads. For bilingual signage in Wales, please refer to the National Application Annex for Wales.

Any use on other roads or any deviation from this authorisation may require the submission of a new proposal and subsequently a new authorisation.

Notes:

1. The authorised sign arrangement is formed of an upper panel, the red 'X’, which currently can only be formed of an LED panel, and a lower panel of the sign to Diagram 7029 “CONVOY VEHICLE NO OVERTAKING” .
2. The illumination of the upper panel red 'X’ would need to automatically switch off any warning beacons and lamps in the rear half of the vehicle.
3. The sign to Diagram 7029 UKSI 2016/362 (TSRGD) [Ref 7.N] (Schedule 13 Part 6 Item 36) on the lower panel is varied to 100mm x-height. Font, format and form to be as per the working drawing ' Traffic signs images and drawing [Ref 2.I]'. Sign face material to be to BS EN 12899-1 [Ref 1.N]Class R3B UK.
4. The yellow backing board is formed of sign face material to a minimum of Class RA2/R2 to BS EN 12899-1 [Ref 1.N] .
5. It is essential that the means of switching from this sign to Figure A.9 is done from the operator’s cab. A prism sign was used in the trial vehicle. The roller blind is not prohibited, but there is no known material suitable for a roller blind which meets the above performance classes.
6. The option to form a red cross using individual lamps is not currently authorised. The lamp layout shown is indicative, for details of the precise number and layout of lamps refer to any future relevant sign authorisation.
7. The lower panel is a standardised arrangement, the dimensions of which it is essential to maintain.

Notes:

1. The authorised sign requires the upper panel to be blank or lowered. The lower panel of the sign is required to show Diagram 7404 “HIGHWAY MAINTENANCE” UKSI 2016/362 (TSRGD) [Ref 7.N]with vehicle conspicuity chevrons.
2. The sign to Diagram 7404 (Schedule 13 Part 6 Item 12) on the lower panel is varied to 100mm x-height. Font, format and form to be as per the working drawing. Sign face material needs to be to a minimum of class RA2/R2 to BS EN 12899-1 [Ref 1.N].
3. The yellow backing board is formed of sign face material to a minimum of Class RA2/R2 to BS EN 12899-1 [Ref 1.N].
4. The conspicuity chevrons are formed of red retroreflective material and reflective fluorescent yellow. See TSM Chapter 8 Part 3 Section U4.3 TSM Chapter 8 [Ref 3.I].
5. The overall vertical and horizontal size of the chevron and Diagram 7404 combination should be no less than the size of the Diagram 7029 sign.

The EMCC vehicle(s) needs to meet the following specification and capability:

Images of the trial vehicles are provided below and contractors need to maintain uniformity of vehicle presentation to support ongoing road user comprehension and technique safety. The EMCC vehicle may also perform another function such as a welfare van. However, the only staff who are permitted to travel in the vehicle during an EMCC are the trained operator and any one person supporting, assessing, training or supervising the operator.

The signs on the rear of the EMCC vehicle need to be regularly inspected for cleanliness and reflective condition. To ensure the suitability of the signs and vinyl refer to the sign condition assessment guide in TSM Chapter 8 [Ref 3.I].

This document is published by National Highways on behalf of Welsh Government.

This document forms part of the works specification. It does not purport to include all the necessary provisions of a contract. Users are responsible for applying all appropriate documents applicable to their contract.

This National Application Annex provides information on the traffic signs authorisation process in Wales.

The assumptions made in GG 101 [Ref 1.N] apply to this document.

This document is intended to be read by professionals who understand traffic sign design.

W/1.1 All new and replacement traffic signs shall contain the Welsh language text above (or occasionally to the left of) the English equivalent.

W/1.2 A limited number of bilingual traffic signs are prescribed by the Traffic Signs (Welsh and English Language Provisions) Regulations and General Directions. UKSI 1985/713 1985 [Ref 2.N] Any bilingual sign not covered by these regulations shall be authorised by Welsh Government.

W/1.3 Users of this document shall contact the Welsh Government team for authorisation or other related enquiries through the following email address: Standards_Feedback_and_Enquiries@gov.wales

NOTE Please see below examples of relevant bilingual signs, detailed drawings of which can be found at https://www.gov.wales/traffic-signs-and-road-markings.