Highways Agency

Use of each category of temporary marking material is constrained by factors such as weather, temperature and, in particular, the nature of the road surface to which the marking is to be applied. Section 3 discusses road surface types. The specification for each temporary marking material is dealt with in Section 5.

Wherever practical, for the sake of consistency, the category of temporary marking material/product should be continuous in each direction throughout the traffic management layout.

The removal of conflicting road markings can raise issues that need consideration before a product is specified as a preferred option. An example might be the type of road surface to be encountered and whether it may be damaged by a particular removal process. Section 3 deals with road surface types and Section 4.2 deals with the removal of road markings.

The categories of temporary marking material are given in Sections 2.2.1 to 2.2.4 and in Table 1. Masking is dealt with in Section 2.3.1 to 2.3.3 and Table 2.

2.2 Road markings

2.2.1 Hot Applied Thermoplastic Road Markings

Hot applied thermoplastic road markings perform well in terms of durability, conspicuity, speed of application, cost to apply, and skid resistance. This form of marking is used throughout the network as a permanent marking.

However, the removal of thermoplastic markings is slow and can leave a ghosting of the marking and scarring of the surface. If the surface is to be replaced, and there will be no need to remove the temporary marking, then this is not an issue and hot applied thermoplastic should be the preferred option. On new carriageway surfaces, residues are generally unacceptable. The likelihood of residues on negative texture surfaces is higher than on Hot Rolled Asphalt (HRA) because of the tendency for the hot thermoplastic material to run into the voids within the surfacing layer.

2.2.2 Temporary Road Marking Tape

Temporary road marking tape is durable for up to 3 months subject to satisfactory application and offers good conspicuity and skid resistance, though it is comparatively expensive and is slow to apply because of the surface preparation required. White temporary road tapes are available in a variety of widths including 100mm, 150mm and 200mm.

The chief disadvantage of tape is that it will not adhere to the carriageway surface in wet and/or cold conditions. There are particular difficulties with negative texture surfaces; in the wet, the pumping action of the water can cause the tape to lift from the surface even when correctly applied in dry conditions. Temporary tape can be very hard to remove if it is constantly overrun (see Section 4.1.2).

2.2.3 Temporary Reflecting Road Studs

Temporary reflecting fluorescent green/ yellow road studs may be authorised as an alternative to markings for temporary delineation at road works (see Section 5.2 and Chapter 8 of the Traffic Signs Manual, paragraph 3.3.10). These studs are usually approximately 100x50mm (4"x2") and are made from fluorescent green/ yellow high impact polystyrene, with self-adhesive vinyl reflectors. They are especially noticeable in wet night-time conditions when their reflective system gives good guidance. The raised profile of the stud also acts as an audible warning to drivers if over-run.

Temporary road studs are designed to be trafficked but not constantly or heavily over-run, and higher breakages than normal can occur if scheme designs indicate such use.

These studs can be fixed to the road either with a bituminous hot-melt adhesive (hot-melt) or by way of a sticky butyl/bitumen pad pre-fixed to the stud (self-adhesive).

Hot-melt studs stick well to road surfaces but leave a clear mark on the carriageway after removal, so are less appropriate for new surfaces. They adhere well on dry negative texture surfaces but once again, when removed, they leave a mark on the road surface. The road surface can also be damaged when they are removed.

Self-adhesive studs are fast to lay and remove, and leave minimal traces, but are prone to becoming dislodged, particularly if they are used in place of lane lines. On negative texture surfaces in the wet, there can be problems with the self adhesive studs becoming dislodged because of the pumping action of the water, though the application of a glue prior to installation can help (see Section 4.1.3). This is less of a problem with hot-melt studs.

An issue with temporary road studs is their tendency to 'sink' into the surface if constantly over-run, particularly on thin surfaces with higher binder content (see Section 3). This can be minimised by the use of studs with a large (approximately 100x100mm, 4" x 4") footprint. Hot-melt studs seem to sink less than self adhesive, possibly because the hot-melt bitumen fills in the voids in open texture materials.

Temporary studs cannot be masked and therefore must be removed when they are no longer required.

2.2.4 Road marking paint

Paint is generally applied through an airless spray machine, and can be applied at walking pace. As a road marking, with glass reflective beads applied to the surface, it is very effective, with luminance and retroreflectivity comparable with temporary tape. It is also much cheaper than tape or hot applied thermoplastic. However, because of its thinness, paint is less visible than thermoplastic in the wet. It is less durable than hot applied thermoplastic, but this may be less of a concern for temporary applications.

Road marking paint is a good option in the right conditions (see Section 4.1.4), in terms of both cost and performance on an old carriageway where the road surface is to be replaced and there will be no need to remove the marking. The skid resistance of paint can be improved by the application of antiskid material while it is still wet. When used on new carriageways or carriageways that will not be replaced, paint is almost impossible to remove.

Table 1: Road Marking Options (View table)

2.3 Masking

2.3.1 Hot applied Thermoplastic Road Markings

Black thermoplastic material can be effective in masking existing thermoplastic markings. However, in wet conditions the black material can reflect light and appear as a road marking and it is therefore advisable to apply black grit when laying the black material to give a matt finish to its surface. When additional thermoplastic or paint is used for covering or reinstating existing markings, care must be taken to ensure that the total thickness of the marking does not exceed 6mm.

It is practically impossible to completely re-expose the white thermoplastic marking once it has been overlaid by black thermoplastic. Although it is not always necessary to remove black thermoplastic if the marking is under 6mm, the use of black thermoplastic should only be a temporary measure because wear of the black material will eventually leave the white marking showing through.

2.3.2 Temporary Road Marking tape

When used for masking, the majority of the adhesive area is thermoplastic to which the temporary tape adheres relatively well. The black tape should be 50mm wider than the marking that it is covering. When removed, the tape generally leaves the road surface and the permanent marking in good condition.

2.3.3 Road marking paint

As a masking material, paint can be effective for masking either paint or thermoplastic markings and is fast to apply and is inexpensive, although a black grit must be surface applied to give the required anti-skid characteristic and a matt finish. It is particularly effective masking painted white lines. However, like thermoplastic, application of black paint for masking purposes is a short term solution only because the black paint will wear eventually to reveal white markings underneath.

Table 2: Road Marking Masking Material Options (View table)

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