Interactive signs
We use several types of interactive signs on Kent's roads. These
signs help us to increase road safety.
What is an interactive sign?
An interactive sign, also known as a vehicle activated sign, is
a sign that reacts to the behaviour of drivers.
If a vehicle is moving faster than the speed limit, or if
approaching a hazard, such as a bend, at an inappropriate speed,
the sign will be activated.
Currently, there are around 145 signs around Kent, the majority
of which remind drivers of the speed limit.
Speed limit reminder signs
The interactive speed sign is used to tell drivers that they
have not reduced their speed, after entering a lower speed
limit.
Signs are placed 100 to 250 metres after the start of a lower
speed limit. If a vehicle is travelling above the speed limit, a
radar beam triggers the sign. When this happens, the speed limit is
illuminated on the sign and flashing amber lights come on above and
below that sign. The sign remains illuminated for 4 seconds.
Warning signs
These are the same as existing road signs, except that they
light up in the same way as interactive speed signs. In a limited
number of cases, the words 'slow down' can be added to appear in
the sign.
They are used at sites, such as bends and road junctions, where
there is a specific crash problem. These will be sites where
traditional casualty reduction measures have failed to reduce the
number of accidents caused by speeding.
Can we put these signs anywhere?
We have a policy for the use of interactive signs. They can only
be used where the criteria related to a crash rate, and the level
of abuse of the speed limit, are met.
In addition, where it is practical to erect a sign based on the
following:
- The sign should be installed between 100 and 250 metres from
the start of the lower speed limit
- The road at that point needs to be straight, so that the radar
beam can work
- There should be no significant trees or hedges that would block
the visibility of the sign or the radar beam
- There should be no existing natural or engineered feature close
to the intended sign that already acts as a speed reducing
feature
- Wherever possible, the sign should not be close to residential
properties, or be directly in line with bedroom windows
- The sign is approximately 900mm wide, so sufficient footway or
verge width is necessary and additional space to ensure that the
sign is not hit by passing vehicles.
Who can request that an interactive sign be put in place?
Parish councils can fully fund a sign that we will put in place,
if the above criteria are met. Members of the public who think that
an interactive sign would be useful on a particular stretch of road
should talk to their parish council.
The cost of installing and maintaining the signs means that we
can place only a small number of signs each year, unless outside
funding is available.