Charlton Road Transport Assessment
Missing information
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No LINSIG output file has been provided for the High Street/Charlton Road
junction.
New Appendix D includes this file.
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PICADY output files have not been provided for either the K4 site access/Bristol
Road or K4 site access/Charlton Road junctions.
New Appendix D includes this file.
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In Appendix C there are a number of network flow diagrams without titles, and
some are blank. The 2007 Friday AM base network flow diagram appears to be
missing, as are the 2018 Friday AM and PM base network flow diagrams. No
network flow diagrams have been provided for the 2018 with development
scenarios (Friday AM, Friday PM and Saturday).
There is no Friday AM base network flow diagram. Saturday Surveys were
surveys were carried out in October 2007 and these were given to B&NES to
adjust the existing Friday AM SATURN model and build a Friday PM SATURN
model.
The 2018 Friday AM and PM base network flow diagrams are contained within
Appendix U ‘October 2008 SATURN Modelling Report’ (Figures ‘Keynsham
Model Turning Movements by Scenario AM’ and ‘Keynsham Model Turning
Movements by Scenario’). However for ease of purpose these network flow
diagrams have been reproduced within the new Appendix C.
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In Appendix D, the file names for the junction capacity assessments do not
correlate with their titles in section 5 of the Transport Assessment. Some pages
are missing from the capacity assessments. The Ashton Way/Charlton Road 2018
Friday PM, Charlton Road/St Ladoc Road 2018 Friday PM, High Street/Rock
Road/Temple Street 2018 Saturday base and the High Street/Rock Road/Temple
Street 2018 Saturday with development ARCADY output files are all missing
page 3.
The above matters have been addressed in the new Appendix D.
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A layout has been provided for the proposed K4 site access/Bristol Road junction,
but no other junction plans have been provided.
The K4 Site Access / Bristol Road junction is the only junction that is being
altered. No amendments are proposed to be made to K4 Site Access / Charlton
Road access and all other junctions where alterations to the junction are
recommended have been made from ‘sketch’ diagrams to provide base
information. However, as these junction improvements are to be funded by four
developers, full design is the responsibility of B&NES Council.
Issues requiring clarification
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Section 5 of the Transport Assessment provides no details of the trip generation or
distribution used other than reference to Appendix U and Mott MacDonald’s
“Keynsham Traffic Model Forecasting Report”. The most recent version of this
report issued to Bath & North East Somerset Council was version B (3rd
November 2008). However, White Young Green (WYG) has included version A
(October 2008) in Appendix U.
Trip generation was provided by Motts and is given within Appendix U ‘ October
2008 SATURN Modelling Report’ (Table 2, Page 11).
As was advised to B&NES Officers at the meeting on 17th September 2009 due to
the programme WYG modelling work would start on the 1st October 2009 when
the report was to be received. The report was finally received on the 10th October
and work began immediately in order to meet the target deadline for the Planning
Application submission. All modelling work was based on the report issued on the
10th October and therefore it was the report appendiced.
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Because no 2018 with development network flow diagrams have been provided
by WYG, there is no evidence to indicate that traffic has been redistributed to
reflect the proposals for ‘priority one-way working’ on the site access from
Charlton Road.
The 2018 development network diagram is included in the Motts report
(Appendix U) which was based on the Charlton Road access with ‘priority one
way working’.
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No details have been provided of the calculations made to produce the 2018
Saturday base traffic flows or Saturday 2018 with flows, and no network flow
diagrams have been provided.
It was not possible to reproduce the traffic distribution for the Friday 2018 PM
peak given within the Motts SATURN report. Therefore no 2018 Saturday base
flows or forecast flows were produced. Motts had previously stated that the
development generation and distribution would be the same for the Friday PM and
Saturday peak and therefore it would be only the background traffic that would
alter. A comparison of the Friday PM & AM base (from the model report) and the
Saturday surveyed flows has been provided within the TA. Where traffic flows are
less in the Saturday peak than either the Friday PM or AM peaks it has been
explained that the Friday PM or AM peak is the worst case scenario and no
modelling of the Saturday peak has been undertaken. The only junction where this
was not the case was the Rock Road / Temple Street junction where traffic flows
on the Saturday appeared to be significantly higher on the Temple Street (S) arm
compared to the Friday PM Base flows within the Motts report. Therefore, for this
one location and unable to reproduce the SATURN models distribution, the 2006
base traffic was subtracted from the 2018 ‘Development Scenario’ traffic and then
the 2007 Saturday surveyed flows were added, as explained in Section 5.6.12 of
the TA.
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For the Bristol Road/St Ladoc Road junction, the LINSIG output file indicates
that, in the Saturday 2018 AM period, 172 pcus turn in gaps, and that 12 pcus turn
in the intergreen period. WYG needs to provide justification for the use of these
figures, as they appear very high.
Response to this item will be sent on 23rd February 2009.