2. Initial Assessment Stage 2.1 Rationale for Southern Route Corridor Options Removal 2.2 Northern Route Corridor Options

2. Initial Assessment Stage

The initial assessment stage covers the work undertaken in the period from January to March 2008.

The assessment matrices included in Appendix 2 identify the significant environmental, engineering, relative scheme cost and economic factors assessed during this period in relation to each of the route corridor options considered. These tables provided the rationale for the decisions on route corridor option removal at the initial assessment stage and are discussed below.

2.1 Rationale for Southern Route Corridor Options Removal

2.1.1 South Corridor Option 4

The reasons why South Corridor Option 4 is significantly less advantageous than other corridors are as follows:

• In traffic economic terms the vehicle kilometres are significantly higher than Route Corridor Options 1 to 3. This is as a result of the majority of traffic movements coming from the east on the A90 or south east on the M9.
• Presence of collapsed mine workings and large number of shafts within corridor area, which would impact on the programme and cost of the works.
• Comparative cost is some 65% higher than the base South Corridor Option 1 and was not considered to provide value for money as it did not provide a significantly greater level of service for traffic (e.g. M9 West traffic) or provide for a reduction in vehicle kilometres travelled.

As a consequence of the above it was recommended that South Corridor Option 4 should not be taken forward for further consideration.

2.1.2 South Corridor Option 5

The reasons why South Corridor Option 5 is significantly less advantageous than other corridors are as follows:

• Cost is some 86% higher than the base South Corridor Option 1.
• The cost of providing the new M9 links was not proportional to the levels of traffic anticipated and was not considered to provide value for money.
• Overall, the environmental impact was considered likely to be higher than the other corridors under consideration, for example land take and severance.
• The western section of the corridor passes along the edge of a known mine workings area and additional investigation and treatment would impact on the costs and programme.

As a consequence of the above it was recommended that South Corridor Option 5 should not be taken forward for further consideration.

2.1.3 South Corridor Option 6

The reasons why South Corridor Option 6 is significantly less advantageous than other corridors are as follows:

• In traffic economic terms the vehicle kilometres are significantly higher than South Corridor Options 1 to 3. This is as a result of the majority of traffic movements coming from the east on the A90 or south east on the M9.
• Presence of collapsed mine workings and large number of shafts within corridor area, which would impact on the programme and cost of the works.
• Comparative cost is some 63% higher than the base South Corridor Option 1 and was not considered to provide value for money as it did not provide a significantly greater level of service for traffic (e.g. M9 West traffic) or provide for a reduction in vehicle kilometres travelled.

As a consequence of the above it was recommended that South Corridor Option 6 should not be taken forward for further consideration.

2.1.4 Combination of Corridor Options

To provide direct vehicular access from both the A90 and M9 the following combinations of corridor options were also considered:

• South Corridor Options 1 and 2.
• South Corridor Options 1 and 4.
• South Corridor Options 1 and 6.

No further combinations of corridor options were considered feasible.

2.1.5 Combination of South Corridor Options 1 and 4

The reasons why the combination of South Corridor Options 1 and 4 is significantly less advantageous than other corridors are as follows:

• Presence of collapsed mine workings and large number of shafts within corridor area, which would impact on the programme and cost of the works.
• Comparative cost is some 165% higher than the base South Corridor Option 1 and was not considered to provide value for money as it did not provide a significantly greater level of service for traffic (e.g. M9 West traffic).

As a consequence of the above it was recommended that the Combination of South Corridor Options 1 and 4 should not be taken forward for further consideration.

2.1.6 Combination of South Corridor Options 1 and 6

The reasons why the combination of South Corridor Options 1 and 6 is significantly less advantageous than other corridors are as follows:

• Presence of collapsed mine workings and large number of shafts within corridor area, which would impact on the programme and cost of the works.
• Comparative cost is some 163% higher than the base South Corridor Option 1 and was not considered to provide value for money as it did not provide a significantly greater level of service for traffic (e.g. M9 West traffic).

As a consequence of the above it was recommended that the Combination of South Corridor Options 1 and 6 should not be taken forward for further consideration.

2.2 Northern Route Corridor Options

The level of overall differentiation between North Corridor Options 1, 2 and 3 were not considered to be significant enough to rule any of the corridors out at the initial assessment stage. The corridors were reviewed and, although there are higher costs with some corridors and buildability issues with others, it was recommended that all three are taken forward for further consideration.