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T.P.D.M. V.2.5
5.4.6 Rumble Strips
5.4.6.1 Rumble strips are a further aural and tactile warning device very similar to rumble areas, but
rather than broad patches consist of narrow strips placed at regular intervals, normally used on
single carriageway roads, but may in certain circumstances be appropriate on dual carriageway
roads.
5.4.6.2 Various types of material have been used including raised concrete strips, but these are not
recommended. However, strips formed from 13mm-19mm road stone chippings set onto the road
surface by using epoxy resin have had some degree of success and are generally recommended
where it is considered that rumble strips should be provided.
j.4.6.3
The rumble strips formed from roadstone chippings should be 1m wide spaced at intervals of 7m
apart, with at least 20 No. being used, and laid only on the approach to the hazard.
5.4.6.4 The location of the rumble strips should be in advance of any warning sign warning of the hazard
and generally not closer than 30m to such a sign.
L4.6.5
i.4.6.6
Rumble strips like rumble areas do not necessarily reduce the approach speed of vehicles, and in
fact evidence is that only slight reductions in speed are obtained. However they do act a "wake
up" device, which does alert drivers to the hazard ahead and in this respect have been found to
reduce accidents.
Rumble strips can cause problems in respect of the noise generated and the vibration effect
caused. In the case of the former careful consideration must be given regarding the use of rumble
strips if there are residential developments or hospitals or schools nearby, particularly if unladen
goods vehicles are likely to use the route as these can be the worst offenders. In respect of the
vibration effect these can cause goods to be dislodged, and given that many goods vehicle
operators do not pay proper attention to the loading of their vehicles it may not be advisable to
use rumble strips on route heavily used by these vehicles.
.4.6.7 Rumble strips of whatever type should not be used in marginal strips or hard shoulders to warn of
adjacent barrier fences. Apart from the fact they interfere with the drainage and collect rubbish, it
is far safer to leave the marginal strip vacant of any kind of obstruction. Additionally in the event
of a vehicle breaking down there is less liklihood'of the vehicle being moved onto the marginal
strip because of the obstruction caused by the rumble strips. Also it is likely to cause occupants
of the vehicle to walk along the cariageway rather than the marginal strip to avoid the rumble
strips.
.4.6.8 The provision of narrow transverse rumble strips to separate a carriageway from an adjacent tram
lane or similar, or to separate merging/diverging carriageways is not recommended, as these are
of doubtful value and may in fact increase the potential for an accident to occur rather than
decrease it. It is also relevant that they do not actually prevent a vehicle straying onto the
supposedly "protected" area and depending on the type of rumble strip and the type of vehicle
they could cause the vehicle to be trapped in that area even if only momentarily. These types of
rumble strips can also be potentially dangerous to cyclists and motor cyclists.
.4.6.9 At the start of the rumble strips, described in paragraphs 5.4.6.2 and 5.4.6.3 traffic sign 454
"Uneven road" should be erected in accordance with Table 2.2.2.1 of Chapter 5, Volume 5,
together with the supplementary plate, traffic sign 784, indicating the distance over which the
rumble strips extend.
.4.6.10 As with rumble areas, drivers on the approaches to rumble strips may in order to avoid them,
travel on the offside of the road where strips have not been laid. If this is likely to cause a
problem the use of double white lines to prevent this may need to be considered.