1. At the time of undertaking the study, 2010/11 budgets had not been finalised. Refer to Appendix B.3 for further details, which indicate some budgets have already been reduced below those assumed for the Base Case.
2. The increase in funding for Scenarios 2 and 3 in the second 10 year period reflects an assumption that funding will become available in future to improve the network back towards current conditions.
3. A 2002 price base was used to enable comparison across studies completed at different times, as required by STAG.
4. Further details on the road network are available at:
5. Net Present Value is the difference between the present value of costs and benefits, discounted to 2002 prices. A negative NPV means that the reduction in benefits caused by reduced road maintenance expenditure is larger than the saving made in the road maintenance expenditure.
6. It is noted that specifically for trunk roads, the NPV for Scenario 2 is slightly worse than Scenario 3 but the difference is small. The result is considered within the margins of error due to challenges of modelling long term road conditions, as discussed further in Appendix B.
7. The ratio of reduction in benefits to reductions in expenditure from Table 5.1.
8. It is likely that winter maintenance issues are a major driver of public perception of road performance. Whilst winter maintenance was not the subject of this study, it is important to note that there is a link between overall maintenance impacts and the effects of winter conditions and operations but this has not been investigated.
9. The reason it is not exactly twice as much is due to the different funding streams in Years 10 to 20.