Newlands Cross Upgrade EIS - European Investment Bank

South Dublin County Council Newlands Cross Upgrade
Traffic Modelling: Working Paper No. 2
1. INTRODUCTION
Arup Consulting Engineers have been commissioned by South Dublin County Council
(SDCC) to prepare Preliminary Design and EIS for a Grade Separated Interchange at the
N7/R113 Newlands Cross Junction.
The existing signal-controlled junction at the Newlands Cross operates at capacity during peak
periods. This results on extensive queues and delays on its N7 and R113 approaches. The
proposed junction upgrade will significantly increase capacity at the Newlands Cross, which .
may cause traffic reassignment in the local area. Therefore the use of an appropriate traffic
modelling tool was required to provide robust traffic flow forecasts to inform the design
process and economic and environmental assessments.
Following consultation with SDCC and the Dublin Transportation Office (DTO) a proposed
modelling methodology was approved in November 2005. The model validation and traffic
forecasting tasks presented in this report were done in accordance with this methodology. A
Base Year 2005 AM Peak SATURN Local Area Model based on a cordon model from the
DTO’s Dublin AM Peak Strategic Model was produced and validated in January 2006.
Following model validation, 2009 and 2024 opening and design year AM Peak SATURN
runs were produced for both the ‘Do Minimum’ and ‘Do Something’ scenarios in order to
forecast future traffic volumes on the local road network with and without the proposed
junction upgrade. It should be noted that subsequently the assumed Opening Year was
amended to 2010, and thus the modelled results were extrapolated from 2009 to produce 2010
flow data (and similarly for 2025).
This report provides information on each of the steps undertaken for the validation of the
Newlands Cross Upgrade Local Area Model (LAM). Additionally, the report also provides
information on the demand forecasting and network update work undertaken to produce
opening and design year scenarios, as well as a summary of the SATURN forecast flows.
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24 March 2006