Newlands Cross Upgrade EIS - European Investment Bank

South Dublin County Council N7 Newlands Cross Upgrade
Environmental Impact Statement
5.9 Cost Benefit Analysis
Arup Consulting Engineers
5.9.1 Approach to Cost Benefit analysis
A cost-benefit analysis using COBA (revision 11b) was undertaken to assess the theoretical
economic benefits of the Scheme (the Do-Something) in terms of travel and accident benefits,
when compared to the Do-Minimum Scenario.
The benefits incorporated in the cost benefit analysis include travel time savings to road based
transport as a result of the reduction in traffic congestion on the N7 and R113 junction, as well
as changes in vehicle operating costs and accidents. The costs take account of the capital
costs of providing the infrastructure.
An evaluation period of 30 years was adopted with the costs and benefits discounted over that
period to a base year of 2002 using a 5% discount rate.
5.9.2 Cost Benefit analysis results
The COBA analysis is based on 2002 prices, with all costs and benefits discounted to 2002 (at
a rate of 5% per annum). The costs and benefits are shown in Table 5.6.
Table 5.6: Cost-Benefit Analysis Summary
Impact Costs / Benefits (€M)
Present Value of Benefits (PVB) 392.5
Present Value of Costs (PVC) 43.5
Net Present Value (NPV) 349
Benefit to Cost Ratio (BCR) 9.0
Note: Values are 2002 prices discounted to 2002
The total cost of the Scheme at 2007 prices has been assumed as €96 million exclusive of
VAT, which translates to a value of €43.5 million after conversion (ie. reduction) to 2002
prices and discounting from year of construction (2009-10) to 2002 values.
The COBA results indicate that the combined monetary benefit of time savings and vehicle
operating costs amount to a Present Value of Benefits of €392 million. Allowing for capital
and maintenance costs of €43.5M (in 2002 prices, discounted to 2002), a Net Present Value of
€349 M positive benefits is calculated.
The cost benefit analysis for the Newlands Cross scheme proposals demonstrate clearly that
significant economic travel would accrue from the proposed Scheme, by far the largest
element of the benefits being the value of the time savings resulting from the reduction in
traffic congestion on the network.
5.10 Construction Traffic
5.10.1 Traffic Management Arrangements
The proposed approach to traffic management during the construction period includes for
providing a reasonable level of capacity at the Newlands Cross junction while allowing
sufficient working space for the construction of the overpass structures. On this basis a works
area was identified for the construction of the overpass structures and space was identified for
traffic lanes on the N7 to accommodate the traffic demand through the junction. The
minimum lane provision required was assessed as being three lanes for straight ahead and left
turning traffic both eastbound and westbound, plus a dedicated lane for right turning traffic
December 2007 Page 93