Atkins
Highways & Transportation
260 Aztec West Almondsbury Bristol BS32 4SY England
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Your Ref:
Our Ref: BW5024/TED/1906/20/AJC/jas/65144
21 April
2004
House of Commons
London
SW1AOAA
Robert Key
MP
Dear Sir
AREA
2 TRUNK ROADS AND MOTORWAYS MAINTENANCE AGENCY A36 PLAITFORD
TO WEST WELLOW SPEED AND SAFETY STUDY
Please find
enclosed 1 No. copy of the Final A36 Plaitford to West Wellow
Speed
and Safety Study. The document includes
comments received
during the consultation held in Autumn 2003.
The study
recommends reinforcing the existing 40mph speed limit between
School Road and Fighting Cocks
Farm; providing
engineering
measure through the 50mph speed limit to reduce driver
speeds with the aim of reducing the speed limit to
40mph; reducing
the circulatory
carriageway at Canada Common Roundabout to reduce
vehicle speeds and providing a number of formal and informal
crossings through
the length.
Funding for
this package of work has been obtained for this financial year
and the work is programmed
for implementation
during the summer
2004.
If you have
any comments on the report, please do not hesitate to contact
the undersigned.
Yours faithfully
for and on behalf of
Atkins Highways and Transportation
Angela Carey
Improvements Route Engineer (South)
Enc:
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8.0 Discussion
8.1 Summary of Consultation
In Autumn 2003, Revision 3 of this
document was issued for formal consultation to County Councils,
Police Constabularies, Borough
Councils, District Councils, Parish Councils, local Members
of Parliament, New Forest Committee and Test Valley Road Safety
Council. Full details of the consultation and other comments
received are
contained in Appendix B. Table 8.1 below summarises the objections
and support for each recommendation.
| |
Ban right turns into Whinwhistle Road |
Ban right turns out of Whinwhistle
Road |
Reinforcement of speed limit from School
Road to Fighting Cocks |
Reduction of speed limit from SOmph
to 40mph |
Non-motorised User Safety Improvements |
| Support |
- |
3 |
7 |
9 |
9 |
| Objection |
7 |
4 |
- |
- |
- |
| Other |
1 supports the need for further study
of this proposal |
1 supports the need for further study
of this proposal |
|
Support if speeds can be lowered |
|
Table
8.1 Summary of Results of Consultation
8.2 Right Turn
Bans
Banning the
right turn movement into Whinwhistle Road from the A36 will significantly
impact upon the environment and the
aesthetics
of the area for the residents of Lower Common Road/Buttons
Lane because of the increase in northbound traffic flows, and
by the
anticipated increase in HGVs in the AM peak hour, from 5 to
19 HGVs. This would reduce the incidence of accidents at the
A36
Whinwhistle Road junction (13 of the 19 PI As involved slow
moving or stationary
vehicles at this junction), however it may displace the accident
problem elsewhere.
Banning the
right turn movement from Whinwhistle Road would not significantly
impact upon West Wellow because
traffic to
the
A36 westbound would generally appear to use the alternative
route via
Romsey Road and Lower Common Road already to avoid the Whinwhistle
Road/A36 junction. Banning the right turn would increase
the traffic flow southbound into Romsey Road by 14 vehicles in
the AM peak
hour and by 31 vehicles in the PM peak hour.
Banning the
right turns in and out of the junction would have the affect
of routing
traffic onto less suitable residential,
narrow
roads which pass the local school. Right turn bans are difficult
to enforce without physical measures. The Order may be abused, which
may create a worse accident
situation as drivers would not expect to see this movement. The
majority of consultees objected to banning both right turn movements
at the junction. Appendix B Sections B1 and B2 detail the responses.
It is not recommended that this proposal is taken forward.
8.3 Speed
Limits
Speed reduction
measures are needed on the eastern side of West Wellow where
the speed limit is signed 40mph. The extended
40mph
speed limit towards Fighting Cocks Farm should be reinforced
through increased engineering measures similar to those in the
original
40mph length. The speed survey shows that the speed limit is
not observed by the majority of drivers with the recorded 85th
percentile
speed for every hour being in excess of the 40mph speed limit.
The accident analysis of the accident cluster site at the A36/Whinwhistle
Road Junction shows that 13 of the 19 recorded PIAs were caused
by nose to tail collisions. It is suggested that vehicles are
travelling too fast to react to stationary or slow moving traffic
when vehicles
are turning right into Whinwhistle Road from the A36. The majority
of consultees support of the reinforcement of the speed limit
at this location. Refer to Appendix B Section B3.
The speed limit
on the A36 west of Maurys Lane (50mph limit) is adhered to
in the main between the hours of 06:00 and 20:00.
However
20 PIAs have occurred in the period July 1998 to June 2003
between Canada Common Roundabout and Plaitford, the most common
cause
of accidents being nose to tail collisions. This suggests
that vehicles
are travelling too fast to anticipate slower moving vehicles.
There have also been three PIAs in Plaitford involving pedestrians,
one
accident involved a fatality, therefore it is suggested to
introduce a speed limit of 40mph through Plaitford. The traffic
speeds
along this length are close to the existing 50mph speed limit.
In order
to gain the support of Wiltshire Police (refer to Appendix
B Section B4) to reduce the speed limit, engineering measures
should
be implemented
to bring vehicle speeds closer to 40mph.
8.4 Canada
Common Roundabout
Analysis of
the accident data indicates that there have been four PIAs within
50m of Canada Common Roundabout
in the last 5 years.
As discussed in sections 2 and 3 reduction of vehicle speeds
at the roundabout may result in increased safety at the junction.
Refer to Appendix B Section B10.
The roundabout
has two lanes for traffic on the circulatory carriageway of the
roundabout.
The desirable roundabout entry
deflection, which
slows the vehicles down, is not achieved on this roundabout.
The entry deflection for roundabouts is dictated by the Design
Manual
for Roads and Bridges Volume 6 TD16/93, which states that the
minimum radius at the tightest section of the vehicle entry
path shall
not exceed 100m. From preliminary checks on the roundabout
the entry deflections are greater than this maximum which can
result
in higher speeds across the roundabout.
In order to
achieve the desired entry deflection, and reduce vehicle speeds,
the
circulatory carriageway of the roundabout
can be reduced
to a single lane. This can be achieved by increasing the
size of the roundabout island with coloured surfacing and road
markings
delineating between the running lane and the increased central
island.
A paper published
in 'Nordic Road and Transport Research Volume 12 No.2 August
2000' discusses options to provide safer
roundabout
designs. One of the paper's conclusions is that a single
lane circulatory has a far greater safety record. TD 16/93
para
7.51 states that
the circulatory carriageway width shall lie between 1.0
and 1.2 times the maximum entry width. Reduction of the circulatory
carriageway
width would therefore also require a reduction of the Canada
Road and Lower Common Road entry widths.
8.5 Non-Motorised
User Crossings
The non-motorised
user crossing survey has identified a number of crossing locations
which should be further
investigated. Provision of crossings through the length will
aid in enhancing
the village
environment, assisting in lowering vehicle speeds.
Further investigation of the proposed crossing enhancements is
supported
by all consultees.
Refer to Appendix B Section B5.
9.0 Recommendations
9.1
Existing 40mph Section
Speeding occurs
on the eastern edge of West Wellow on the A36 in excess of the
40mph speed
limit. A reduction in vehicle
speeds
westbound is needed -there is a high proportion of nose to
tail accidents at the A36 Whinwhistle Road junction caused by
vehicles
colliding with others waiting to turn right at the junction.
This is compounded by the undulating vertical alignment on
the approaches
to the junction. In autumn 2002 a number of safety measures
were put in place at the Whinwhistle Road junction, notably improved
surface treatments and signing. In autumn 2003 two safety camera
were erected near Whinwhistle Road junction. The impact of
these
measures should become apparent in the short to medium term.
The erection of a vehicle activated sign and any other measures
on
the westbound approach to Whinwhistle Road warning of queues
ahead should be investigated. The 40mph speed limit through
this section
should be reinforced by adding 40mph roundels to the red patches.
9.2
Existing SOmph Section
Although the
SOmph speed limit through Plaitford is largely adhered to, it
is recommended to lower the
speed limit from
50mph to
40mph to the west of West Wellow and extend this through
Plaitford to
New Road. It is suggested that this would reduce the number
of nose to tail accidents between Canada Common Roundabout
and Plaitford.
Three PIAs involving pedestrians have occurred between
Canada Common Roundabout and Plaitford, one fatal. It is suggested
that lowering
the speed limit would also improve pedestrian safety when
crossing the A36. In order to gain the necessary support
from
the Police
to reduce the speed limit, it is recommended that engineering
measures such as signing, surface treatments and road markings
are implemented
throughout the length.
9.3 Canada
Common Roundabout
It is recommended
that the circulatory carriageway and its approaches are reduced
to one lane to reduce vehicle
speeds
and enhance
non-motorised user safety.
9.4 Non-motorised
User Crossings
Although there
is a relatively small number of PIAs involving pedestrians and
other vulnerable road users,
high traffic
volumes and excessive
speed does suggest a need for a number of formal
and improved crossing points along the A36 between Plaitford
and West
Wellow to reduce
severance. The application of the Highways Agency's
Non-Motorised User Crossing Survey methodology
has identified the need
for the following measures to be considered for NMUs:
- East of
New Road - provide a pedestrian refuge east of the junction;
- Sherfield
English Road - provide dropped kerb to the north-west of the
junction;
- Shoe Inn
- provide a signal controlled crossing at the point where a
cycle path crosses from the southern side
of the A36 to
the northern side;
- Maury's
Lane - provide for safe equestrian crossing of the A36 east
of the junction;
- Slab Lane
- provide a crossing of the A36 between the bus stops east
of the junction;
- Canada
Common Roundabout - consider a signal controlled crossing on
the eastern arms of the roundabout;
- Blackhill
Road - investigate provision of an equestrian crossing of the
A36 near the junction;
and
- Whinwhistle
Road - include improved pedestrian crossing facilities if this
junction is upgraded in the medium to long
term.
Provision
of these crossings should be investigated further and justified through the
Project Appraisal Report process to obtain
funding. |
