Traffic Signs Manual/Chapter 5/2009/23
GENERAL
23.1 Road marking materials and road studs are specified in the appropriate British Standards. These are generally the English language versions of standards published by the European Committee for Standardisation (CEN).
ROAD MARKING MATERIALS
23.2 Road markings are applied using thermoplastic, cold plastic, preformed material or paint. They may be laid as permanent markings or as temporary markings at road works.
23.3 Thermoplastic material is applied hot and sets on laying. It may be applied by a hand or mechanical applicator. It has good durability and is suitable for use on all roads. Mechanical application is most suitable for use on motorways and other high standard roads where it can be laid in long runs using motorised equipment with minimum disruption to traffic.
23.4 Cold plastics are supplied in single or multicomponent forms. The product is laid on the carriageway and a cohesive film is formed by chemical action.
23.5 Preformed thermoplastic road markings are applied by heating the material until it bonds to the road surface by melting or fusion. They provide a simple way to apply arrows, lettering etc. and to reinstate short lengths of line without the need for substantial application and support equipment.
23.6 Preformed cold plastic material is applied to the road surface using an adhesive.
23.7 Preformed tape is produced in sheet or roll form and is either bonded to the road surface or inlaid. Pressure is applied, but not heat. Preformed markings have good durability, are of uniform thickness and do not spread in hot weather or under the weight of heavy traffic. They can be difficult to apply to some surface dressings and block paviors. They are also manufactured in an easily removable form for use at road works.
23.8 Paint is best restricted to roads where the markings are not subject to heavy traffic wear. It is particularly suitable for edge lining, for yellow waiting restriction lines and for parking bays as, being thinner than thermoplastic material, it will not interfere with drainage. The ease and safety in handling paint compared to thermoplastic material, its suitability for laying with motorised equipment and the material's low initial cost, makes paint an attractive economic proposition for such applications.
EUROPEAN AND BRITISH STANDARDS
23.9 Initial laboratory requirements for materials are described in BS EN 1790 for preformed markings and BS EN 1871 for directly laid materials. Requirements for drop-on materials (glass beads and anti-skid aggregates) and premix glass beads are dealt with in BS EN 1423 and 1424 respectively. BS EN 1436 specifies several performance levels for properties such as retroreflectivity, skid resistance and durability. Materials will be classified in accordance with the relevant standard following performance testing. In the UK, this will normally be on the basis of laboratory tests to BS EN 1790 or BS EN 1871 as appropriate, and road trials to BS EN 1824.
23.10 The Specification for Highway Works published by the Stationery Office specifies which performance classes in BS EN 1436 for luminance factor, skid resistance and retroreflectivity are to be used on trunk roads and motorways. As higher retroreflective performance requires additional glass beads, which will reduce the skid resistance, it is not practicable to specify the highest performance class for both. A judgement will need to be made as to which property is more important at any particular location.
23.11 Initial performance requirements for road studs are described in BS EN 1463-1 and the specification for road trials in BS EN 1463-2. The performance levels and classes are listed in BS EN 1463-1. Minimum performance levels to be achieved for use on UK roads are prescribed in the Traffic Signs Regulations and General Directions 2002 (direction 57). Guidance on the correct use of road studs will be found in section 6.
23.12 The following British Standards have been withdrawn as a result of the introduction of European standards:
BS 3262: Parts 1, 2 and 3: 1989 Hot applied thermoplastic road marking materials,
BS 6044: 1987 Pavement marking paints,
BS 6088: 1981 Solid glass beads for use with road marking compounds and for other industrial uses (those sections relating to glass beads for road marking materials),
PD 6518: 1987 Prefabricated temporary road marking materials for use at road works,
BS 7396: 1991 Permanent preformed road markings.
23.13 British Standard BS 7962: 2000 sets out performance requirements for black masking materials. It is not planned to replace this with a European standard.
REFLECTORISATION
23.14 Road markings fall into two categories, those which must be illuminated with retroreflecting material, and those which may be so illuminated (regulation 31). Table [[#table23.1|23-1 lists the diagram numbers of markings which must be reflectorised.
23.15 It is not usually necessary to reflectorise waiting restriction lines as they do not normally have a guidance function. However, reflectorisation may be advantageous where such lines are used on the rural outskirts of a town and the road edge is unkerbed, or where a reflectorised edge of carriageway marking immediately precedes such markings. If the yellow lines are reflectorised, any associated parking bays should be also.
23.16 Reflectorisation is achieved by adding glass beads to the markings. These reflect light from vehicle headlamps back towards the driver, making the markings much brighter than they would otherwise be. Beads are normally premixed into the material. It is only when some of the material has worn away to expose the beads that they become fully effective; to overcome this, glass beads are also applied to the surface as "drop-on material" as the marking is laid. The retroreflection of a marking in wet conditions can be enhanced by providing a prominent surface texture. These profiled markings incorporate a series of near-vertical edges which keep the glass beads clear of the water film which would otherwise largely negate the retroreflective property. BS EN 1436 provides specifiers with several classes of wet performance. Profiled markings may be either of the raised rib type prescribed as diagrams 1012.2 and 1012.3, or may consist of an embossed pattern in the material. Provided this latter type is no thicker than 6 mm overall, it may be applied to any marking. In the case of raised rib markings, the passage of wheels also generally produces an acoustic or vibratory effect (see paras 4.39 to 4.48). Improved visibility in all weather conditions may also be achieved by using a wider line where alternatives are prescribed (see paras 1.13 and 1.14).
| 10011 | 1008 | 10232 | 1041 |
| 1001.1 | 1008.1 | 1024 | 1041.1 |
| 1001.2 | 1009 | 1024.1 | 1042 |
| 1002.1 | 1010 | 1036.1 | 1042.1 |
| 10032 | 1012.1 | 1036.2 | 1046 |
| 1003.1 | 1012.2 | 1037.1 | 10492 |
| 1003.3 | 1012.3 | 1039 | 1062 |
| 1003.4 | 1013.1 | 1040 | 1064 |
| 1004 | 1013.3 | 1040.2 | 1065 |
| 1004.1 | 1013.4 | 1040.3 | |
| 1005 | 1014 | 1040.4 | |
| 1005.1 | 1022 | 1040.5 |
NOTES:
- Except when used in conjunction with diagram 1001.3.
- Except when varied to smallest size for use on a cycle track.
STATUTORY COLOURS
23.17 The colours white and yellow are prescribed for road marking materials. Black material may also be used to mask existing markings, where these need to be temporarily obscured during road works (see para 23.13).
23.18 The standard colour for yellow markings is BS 381C No.355 (lemon); No.309 (canary) is also acceptable. In environmentally sensitive areas, yellow markings to No.310 (primrose) or No.353 (deep cream) may be preferred. Special authorisation is not necessary for any of these shades. Different shades should not be used on adjacent lines, as in certain conditions the lighter colour may appear white when seen in direct comparison with the standard yellow.
APPLICATION OF MARKINGS
23.19 As it is not possible to lay road markings to precise dimensions, and to allow for markings "spreading" in service, some tolerance in the prescribed dimensions is permitted by regulation 12. Specified values may vary by up to 5º for angular measurements and by the tolerances quoted in table 23-2 for linear dimensions. No tolerance is permitted for those angular or linear dimensions which are expressed as a maximum or minimum value. A tolerance of plus or minus 25 mm is normally allowed in the lateral positioning of lane lines.
23.20 It is essential that all types of marking should be skid resistant in wet conditions. This is particularly important where the camber or cross fall is steep, and at junctions. The Specification for Highway Works requires a skid resistance value of not less than 45 (sub-clause 1212.3), except in certain locations where the designer may select a value of not less than 55 (sub-clause 1212.6). This higher value should be used for yellow bar markings (see para 11.7) and it would also be appropriate to use it for other markings which might pose a hazard to a braking vehicle.
MAINTENANCE
23.21 Road markings, including reflecting road studs, must be well maintained if they are to fulfil their purpose. Regulatory markings must be maintained properly if they are to be enforced effectively. Guidance can be found in TD 26 in Volume 8 of the Design Manual for Roads and Bridges (see para 1.4).
23.22 All markings, including reflecting road studs, should be inspected at regular intervals both by day and, where appropriate, for reflectance by night. Retroreflectivity of road markings can be measured by static equipment or by dynamic equipment mounted on a vehicle travelling at normal traffic speeds.
23.23 It is not possible to recommend specific renewal intervals for markings as these will depend upon the type of line, the material comprising the marking and traffic flow. Traffic authorities should keep their carriageway markings under review (particularly on heavily-trafficked roads) to ensure that their effectiveness is maintained at all times.
23.24 Markings should be renewed as soon as possible after resurfacing or on the completion of road works which may have damaged them. Where it is not practicable to restore them immediately using permanent materials, a temporary marking should be used, particularly at sites such as road junctions, if the absence of a marking might give rise to dangerous conditions. Arrangements should be made to protect road studs during surface dressing operations.
| Dimension shown in the diagrams | Allowable tolerance |
|---|---|
| 3 m or more | Up to 30% greater than or 10% less than the specified dimension |
| 300 mm or more, but less than 3 m | Up to 20% greater than or 10% less than the specified dimension |
| 50 mm or more, but less than 300 mm | Up to 15% greater than or 10% less than the specified dimension |
23.25 Where it is not possible to provide temporary road markings, drivers should be warned of their absence by means of advance warning signs. At junctions where all, or any part, of the STOP or Give Way marking has been removed and temporary markings cannot be provided, a prescribed variant of diagram 7012 "NO STOP MARKINGS" or "NO GIVE WAY MARKINGS" should be placed on the minor road near the junction, preferably about 5 - 10 m from the edge of the main carriageway. Where road markings associated with a level crossing are absent, the variant "NO ROAD MARKINGS AT LEVEL CROSSING" should be used. The alternative legends "NO ROAD MARKINGS" and "NO ROAD MARKINGS AT JUNCTION" should be used where appropriate. Where lane lines or centre of carriageway lines on inter-urban roads have been removed (especially where there is no street lighting), a sign bearing the legend "NO ROAD MARKINGS FOR X MILES" or "X YARDS" or, if appropriate, "NO ROAD STUDS FOR X MILES" or "X YARDS" (diagram 7012) should be used with the appropriate distance inserted.
23.26 All obsolete markings and road stud housings, particularly those which may give a misleading indication, should be removed as soon as possible. This is particularly important where new central refuges are installed; the old centre line and any road studs should always be realigned (see table 14-1 for recommended tapers) before the road works signing and guarding is removed.
DRAINAGE
23.27 It is essential that road markings should not prevent a carriageway from draining properly. Even a thin film of standing water can be dangerous in the winter, when it may freeze. Markings may project up to 6 mm above the adjacent road surface (regulation 32), although the ribs of raised rib markings and the centre portion of diagrams 1003.4 and 1049.1 may be higher. In difficult areas, where for instance the cross fall is nearly level, or the road is at the lowest point of a sag curve, it may be preferable to use paint in place of thermoplastic for continuous edge lines, as its negligible thickness will
23.28 Generally a drainage channel of 225 mm should be maintained between markings and the kerbed edge of a road. This will allow water to flow freely and help to ensure that the markings do not become unnecessarily dirty.
This is NOT an official transcription, and should NOT be considered in any way a controlled copy of the work in question.
This document no longer necessarily represents current practice, as it relates to an earlier version of the regulations (TSGRD 2002 as amended at publication date) rather than the current TSRGD 2016 regulations. It should not be used for actual design or operational use without consulting a more recent edition.
This version was transcribed in May 2015, from a 2009 impression.
This work is licensed under the Open Government Licence v3.0 (OGL v.3).
- You are free to:
- copy, publish, distribute and transmit the Information;
- adapt the Information;
- exploit the Information commercially and non-commercially for example, by combining it with other Information, or by including it in your own product or application.
- You must, where you do any of the above:
- acknowledge the source of the Information in your product or application by including or linking to any attribution statement specified by the Information Provider(s) and, where possible, provide a link to this licence;
- If the Information Provider does not provide a specific attribution statement, you must use the following:
- Contains public sector information licensed under the Open Government Licence v3.0.
Public domainPublic domainfalsefalse