Traffic Management Schemes are introduced to solve an identified
problem in one or more roads. The need for a scheme can be
identified in a variety of ways. It may, for example, be a
bad accident record or the concerns of residents that prompts an
investigation. Sometimes the Council adopts an "area wide"
approach to traffic problems, for example, where there is a demand
from several residential roads for "Speed Control Humps." To
deal with this, priority is given to the worst problems first.
Potential schemes are assessed against the following
policies:
- To achieve safe movement by reducing accident
levels.
- To promote and accommodate the maintenance
and improvement of public transport.
- To restrain traffic and safeguard the
environment.
- To seek equitable levels of mobility and
accessibility for all groups of people, particularly for those
presently disadvantaged in mobility terms i.e. people with
disabilities, children, women, the old and the infirm.
- To reduce the impact of commuter
parking.
- To improve pedestrian safety, accessibility
and convenience.
- To promote cycling.
Consultation
The Council consults residents for their views before the
introduction of any new traffic measures. In addition, many traffic
measures require the publication of a formal Notice in the press.
A six week period is allowed for objections to be received.
Formal objections are considered, and schemes may need to be
re-designed with further Notices being published, before a legally
enforceable Traffic Order can be made and the scheme introduced.
The Council, as Highway Authority, is responsible for introducing
and maintaining the physical measures and for making any necessary
Traffic Orders but enforcement of Traffic Orders is the
responsibility of Police.
Components of Schemes
There is no single solution to problems associated with traffic
management. A variety of measures are used sometimes in
combination.
Speed Control Humps and Tables
"Pillow" or "Cushion" Humps
These are a form of speed control hump which are wide enough to
allow a wide wheelbase vehicle to pass unhindered. Buses or a fire
engine are not affected by them, whereas a smaller wheelbase
vehicle, such as a car, would have to have at least one set of
wheels on the hump. Thus cars are slowed, whereas other traffic is
generally unaffected. These are intended to overcome the objections
of the Emergency Services and Bus Companies.
They make possible speed reduction measures in roads that would
otherwise not have them introduced.
"Chicanes" and "Throttles"
Chicanes and throttles are intended to reduce traffic speed by
reducing the available carriageway width throughout a short
length.
Chicanes introduce a physical deflection into the vehicles'
horizontal path, thereby further reducing the vehicle speed.
Throttles narrow the road, frequently to provide a safe crossing
point for pedestrians, sometimes in conjunction with a speed
table.
Kerb Build Outs
At some road junctions visibility is often reduced because of
the shape of the road or because of parked cars. Building out the
kerb into the carriageway can help solve this problem. It provides
protection for motorists emerging from a side road as they can
safely pull further out to see, and be seen. Pedestrians are
similarly protected, have more space to stand and can also see and
be seen better. Cars are forced to park further from a junction or
crossing point.
Width Restrictions
Width restrictions are a self enforcing means of restricting
access for large vehicles. Posts or bollards are placed in the road
about 2.1 metres (7 feet) apart, such that vehicles wider than this
cannot pass between them. There must be an alternative route
available for large vehicles such as refuse collection vehicles and
this sometimes limits their application in residential areas.
Sometimes a gate is provided for use of fire engines and other
emergency vehicles. The gate is kept locked but emergency vehicles
carry keys.
Many residents mistakenly ask for width restrictions to be
introduced as a means of slowing down traffic. Width restrictions
do not, and are not intended to, reduce traffic speed.
One Way Streets, Banned Turns and No Entry
These help control traffic movements, without completely
restricting access. They can stop commuter "rat-runs" which
occur.
One-way working may be for the whole length of a street, or in a
short length at one end - a one-way plug.
A suitable alternative route must be identified and available
for traffic travelling in the opposite direction to the one-way
street, or for traffic needing to turn in the direction of the ban.
This alternative would not normally be via a residential road.
One-way streets often lead to an increase in traffic speed.
Short lengths are difficult to enforce if drivers are irresponsible
and determined enough to drive against the one-way. This is
dangerous and illegal.
Some residents find one-way streets and banned movements
inconvenient as they may result in reduced levels access to their
homes.
Road Closures
These are an effective, self-enforcing, means of stopping all
through traffic movements. Roads are usually closed by a barrier
with an emergency access gate for Police, Fire and Ambulance
vehicles.
Near to a road closure, it is necessary to make provision, on
either side, for large vehicles to turn round. That is why it is
not used in many residential areas. It may also be inconvenient to
some residents as Road Closures limit access.
Standard Roundabouts
Standard roundabouts are intended to assist at a junction where
there is a heavy right turning movement. They work best where
traffic flows on each arm are reasonably well balanced and they
allow traffic to flow comparatively freely.
Mini Roundabouts
Mini roundabouts are introduced both as a means of reducing
accidents, by slowing traffic, and to assist right turning
movements. Their advantage over full size roundabouts is that they
can often be accommodated within the existing road space, without
expensive road widening.
As at a full size roundabout, the rule at a mini roundabout is
"give way to traffic from the right".
Pedestrian Crossings
The Council receives many requests for new and upgraded
pedestrian crossings, (i.e. zebra or signalled crossings) each
year. Requests are often made by residents and each is examined on
its individual merits. Many requests are not justified because of
low levels of pedestrian movement.
The following factors are taken into consideration in assessing
the need for a crossing:
- The record personal injury accidents
involving pedestrians.
- The volumes of vehicular and pedestrian
traffic and the potential for conflict between pedestrians and
vehicles.
- The difficulty that pedestrians face from
traffic speed and volumes.
- The lengths of time pedestrians have to wait
before they can cross.
- Proximity of locations which attract
pedestrian activity through the day, e.g. proximity to
stations.
Pedestrian crossings do have shortcomings and are not the answer
in every case. Motorists who use the road regularly tend to ignore
crossings if not often used. Similarly pedestrians can rely on the
crossing and, rather than watching the traffic, assume that,
because a "green man" is showing, the traffic will stop. Both of
these problems can result in an increased risk to pedestrians
rather than a decreased risk.
Pelican/ Puffin Crossings
These signalised crossings are used on roads which have high
traffic volumes, high traffic approach speeds or very high
pedestrian flows. The time allocated for pedestrian crossing
movement is dictated by Department for Transport guidelines
and is based upon the width of the road.
Zebra Crossings
These are used on roads of less importance, with lower
pedestrian or traffic flows.
Traffic Islands/Pedestrian Refuges
Where a formal pedestrian crossing is not justified these can be
installed. They assist pedestrians by letting them cross the road
in two stages. The restriction to the use of this measure is the
width of the carriageway. It must be at least 8.0m wide to allow
for the island and two lanes of traffic.
Facilities for the Disabled
Tactile paving is used at all zebra and signalised
crossings to help people with impaired vision. Similar tactile
paving is also used at many ramped crossing points. Many
single signalised crossings have audible signals, as well as
the green man signal, to indicate when it is safe to cross the
road.
Some staggered two stage pelican/ puffin crossings and some
junction signals are fitted with a tactile knob on the pedestrian
push-buttons, rather than an audible signal. This is so that
visually impaired people can tell which part of the staggered
crossing or junction is safe to cross.
Junction Entry Treatments
A junction entry treatment is placed across the carriageway of
the minor road at a road junction. The object is to show motorists
that they are leaving a main road and entering a residential area
and to raise the priority for pedestrians crossing the junction.
This treatment often has a speed table, kerb build out and gateway
features.
White Carriageway Markings
Carriageway markings are a cheap and cost effective way of
reducing accidents. At junctions they provide an indication of
priorities, and as centre or lane lines, they indicate the best
line for vehicles to follow. White markings are generally
advisory.
Lane arrows are used on the approaches to traffic signalled
junctions to indicate which lane should be used for turning and
straight ahead movements. SLOW markings are often used on the
approach to a hazard.
Areas of central cross hatching, commonly called "ghost island"
markings, are useful as a means of reducing accidents by separating
on-coming traffic, reducing traffic speed and providing safe right
turning areas. These, along with central traffic islands, have been
shown to play a major part in reducing motor cycle accidents.
Continuous White Lines
Continuous white centre line markings must not be crossed and
are generally used to prevent overtaking and reduce speeds in roads
with poor visibility due to bends or the crests of hills. These are
also used sparingly so that they are more effective and have more
impact when they are used. There are criteria for the introduction
of these markings based upon the speed of traffic and the
visibility distances.
It is also an offence to park in any section of road that is
marked with a continuous white line. Continuous white lines may
only be crossed by traffic that is turning right
Road Junctions
There are a number of grades of Priority Junction throughout the
County. Some junctions in residential areas may have no form of
priority road marking. This is for amenity and maintenance reasons.
Markings will, however, be provided if there is an identified road
safety problem.
Other junctions may have a "give way" line; "give way line and
triangle marking" "give way line, a triangle marking and a give way
sign"
Some junctions may have a "Stop" sign and marking. These are
used infrequently, in order to ensure that they have more impact on
motorists. There are strict criteria, relating to visibility
distances of approaching traffic, which must be met before "Stop"
signs can be introduced.
Traffic Signals and Control
Traffic signals are designed to optimise and control traffic at
a junction by sharing out the time to different arms of the
junction and to pedestrians. Traffic signals do not always solve
accident problems.
