Key Findings and Recommendations

Introduction

The following sections summarise the key findings of the DMRB Stage 1 Assessment, specifically the potential impacts of the improvement strategies as identified by the Engineering, Environmental and Traffic and Economic Assessments.

They also describe how the improvement strategies compare in terms of their advantages and disadvantages and provide recommendations as to which improvement strategies should be taken forward for further assessment at DMRB Stage 2.

It is important to note that these recommendations do not preclude consideration of alternatives that may be appropriate at DMRB Stage 2. The recommendations indicate an improvement strategy which should, based on the level of assessment undertaken in this report, be considered further in accordance with a DMRB Stage 2 Assessment and which could potentially be developed in more detail to become the overall preferred route option.

Assessment of Improvement Strategies

Improvement Strategy 1

Following assessment of Improvement Strategy 1, the key findings are as follows:

This improvement strategy aligns fairly well with the scheme objectives.
Three Category B listed buildings, two non-designated historic buildings and one non-designated archaeological site lie within the improvement strategy.
This improvement strategy is likely to have the lowest level of traffic reduction on the existing A75 of all the offline improvement strategies. It is longer and less direct than the equivalent section of the existing A75 and could therefore be seen as a less attractive alternative.
It is likely that this improvement strategy will require a greater number of intermediate junctions to connect to the existing local roads network compared to the other improvement strategies.
Whilst diverting some traffic away from built up areas, this improvement strategy would likely have significant adverse effects on the surrounding landscape as it is the longest.
This improvement strategy intersects four ancient woodland parcels (3.99ha) and six parcels of native woodland (3.32ha). In addition, as it is the longest, this improvement strategy would likely result in a greater degree of habitat loss and fragmentation.
This improvement strategy would involve significant land take potentially affecting residential, agricultural, commercial, and community receptors.
This improvement strategy would likely have significant and/or large adverse effects in relation to geology, materials and waste, noise and vibration and the water environment.
This improvement strategy passes through undulating topography which would result in significant earthworks.
There are additional constructability considerations associated with this improvement strategy due to its interaction with A712.
This improvement strategy would likely be the most expensive as it is the longest.

Based on these key findings, Improvement Strategy 1 is less advantageous than Improvement Strategies 2, 4, 5 and 6. It is therefore recommended that Improvement Strategy 1 is not taken forward for further assessment at DMRB Stage 2.

Improvement Strategy 2

Following assessment of Improvement Strategy 2, the key findings are as follows:

This improvement strategy aligns fairly well with the scheme objectives.
Two Category B Listed Buildings and six non-designated archaeological sites lie within the improvement strategy.
This improvement strategy is likely to have lower levels of traffic reduction on the existing A75 in comparison to other offline improvement strategies. It is longer and less direct than the equivalent section of the existing A75 and could therefore be seen as a less attractive alternative.
It is likely that this improvement strategy will require a greater number of intermediate junctions to connect to the existing local roads network compared to some other improvement strategies.
Whilst diverting some traffic away from built up areas, this improvement strategy would likely have significant adverse effects on the surrounding landscape.
This improvement strategy intersects two areas of ancient woodland (1.07ha) and four parcels of native woodland (1.48ha). In addition, as it is the third longest, this improvement strategy would likely result in a greater degree of habitat loss and fragmentation.
This improvement strategy would involve significant land take potentially affecting residential, agricultural, commercial, and community receptors however, the land take would be less than the longer improvement strategies.
This improvement strategy would likely have significant and/or large adverse effects in relation to geology, materials and waste, noise and vibration and the water environment.
This improvement strategy passes through undulating topography which would result in significant earthworks however, these earthworks would be less significant than the longer improvement strategies.
There are additional constructability considerations associated with this improvement strategy due to its interaction with A712.
This improvement strategy would likely be the third most expensive.

Based on these key findings, Improvement Strategy 2 is more advantageous than Improvement Strategies 1, 3 and 6. It is therefore recommended that Improvement Strategy 2 is taken forward for further assessment at DMRB Stage 2.

Improvement Strategy 3

Following assessment of Improvement Strategy 3, the key findings are as follows:

This improvement strategy does not align well with all scheme objectives. As it is online, it is unlikely to meet the scheme objective to reduce environmental impacts and severance caused by strategic traffic using the A75 Trunk Road within Springholm and Crocketford, with limited contribution to the other objectives.
Seven Category B Listed Buildings, nine non-designated historic buildings and two non-designated archaeological sites lie within the improvement strategy.
This improvement strategy would likely have the least adverse effects on the surrounding landscape as it is online.
This improvement strategy intersects one area of ancient woodland (0.10ha) and three parcels of native woodland (1.26ha). In addition, as it is the shortest and is online, this improvement strategy would likely result in the lowest degree of habitat loss and fragmentation.
This improvement strategy is the shortest and would likely involve the least total amount of land take however, as it is online, it is more likely to have a significant effect on residential, agricultural, commercial, and community receptors.
This improvement strategy would likely have significant and/or large adverse effects in relation to geology, materials and waste, noise and vibration and the water environment.
This improvement strategy is online and would therefore not result in significant earthworks.
This improvement strategy would likely be the second least expensive.
This improvement strategy would not reduce traffic through the villages of Springholm and Crocketford.
The buildability of this improvement strategy would be more challenging than others with significant traffic diversions likely required during construction. In addition, due to the urban setting of this improvement strategy, it is likely that significantly more utility diversions will be required in comparison to other improvement strategies.
This improvement strategy would require additional health and safety measures during construction due to the proximity to the local community.

Based on these key findings, Improvement Strategy 3 is less advantageous than all other improvement strategies. Specifically, this improvement strategy fails to meet all the scheme objectives. It is therefore recommended that Improvement Strategy 3 is not taken forward for further assessment at DMRB Stage 2.

Improvement Strategy 4

Following assessment of Improvement Strategy 4, the key findings are as follows:

This improvement strategy aligns well with the scheme objectives.
Four Category B Listed Buildings, one non-designated historic building and two non-designated archaeological sites lie within the improvement strategy.
This improvement strategy is likely to have higher levels of traffic reduction on the existing A75 in comparison to some other offline improvement strategies, particularly Improvement Strategies 1 and 2. It is shorter and more direct than the equivalent section of the existing A75.
It is likely that this improvement strategy will require fewer intermediate junctions to connect to the existing local roads network compared to the other improvement strategies.
This improvement strategy would likely have less significant adverse effects on the surrounding landscape as it is the second shortest.
This improvement strategy intersects two parcels of native woodland (0.62ha). In addition, as it is the second shortest, this improvement strategy would likely result in a lesser degree of habitat loss and fragmentation.
This improvement strategy would involve land take that potentially affects residential, agricultural, commercial, and community receptors however, the land take would be less than the longer improvement strategies.
This improvement strategy would likely have significant and/or major adverse effects in relation to geology, materials and waste, noise and vibration and the water environment.
This improvement strategy passes through undulating topography which would result in significant earthworks however, these earthworks would be less significant than the longer improvement strategies.
This improvement strategy would likely be the least expensive.

Based on these key findings, Improvement Strategy 4 is more advantageous than all other improvement strategies. It is therefore recommended that Improvement Strategy 4 is taken forward for further assessment at DMRB Stage 2.

Improvement Strategy 5

Following assessment of Improvement Strategy 5, the key findings are as follows:

This improvement strategy aligns well with the scheme objectives.
Four non-designated historic buildings and three non-designated archaeological sites lie within the improvement strategy.
This improvement strategy is likely to have higher levels of traffic reduction on the existing A75 in comparison to some other offline improvement strategies, particularly Improvement Strategies 1 and 2. It is shorter and more direct than the equivalent section of the existing A75.
It is likely that this improvement strategy will require fewer intermediate junctions to connect to the existing local roads network compared to other improvement strategies.
Whilst diverting traffic away from built up areas, this improvement strategy would likely have significant adverse effects on the surrounding landscape.
This improvement strategy intersects ten parcels of native woodland (6.38ha). Despite being the third shortest, this improvement strategy lies partially within the Milton Loch SSSI therefore it could result in a greater degree of habitat loss and fragmentation.
This improvement strategy would involve significant land take potentially affecting residential, agricultural, commercial, and community receptors however, the land take would be less than the longer improvement strategies.
This improvement strategy would likely have significant and/or large adverse effects in relation to geology, materials and waste, noise and vibration and the water environment.
This improvement strategy passes through undulating topography which would result in significant earthworks however, these earthworks would be less significant than the longer improvement strategies.
This improvement strategy would likely be the third least expensive.

Based on these key findings, Improvement Strategy 5 is more advantageous than Improvement Strategies 1, 2, 3 and 6. It is therefore recommended that Improvement Strategy 5 is taken forward for further assessment at DMRB Stage 2.

Improvement Strategy 6

Following assessment of Improvement Strategy 6, the key findings are as follows:

This improvement strategy aligns well with the scheme objectives.
One Category B listed building, two non-designated historic buildings and three non-designated archaeological sites lie within the improvement strategy.
This improvement strategy is likely to have the highest levels of traffic reduction on the existing A75 in comparison to all other improvement strategies. It is shorter and more direct than the equivalent section of the existing A75.
It is likely that this improvement strategy will require a greater number of intermediate junctions to connect to the existing local roads network compared to some other improvement strategies.
Whilst diverting traffic away from built up areas, this improvement strategy would likely have significant adverse effects on the surrounding landscape as it is the second longest.
This improvement strategy intersects six parcels of native woodland (3.28ha). In addition, as it is the second longest, this improvement strategy would likely result in a greater degree habitat loss and fragmentation.
This improvement strategy would involve significant land take potentially affecting residential, agricultural, commercial, and community receptors.
This improvement strategy would likely have a significant and/or large adverse effects in relation to geology, materials and waste, noise and vibration and the water environment.
This improvement strategy passes through undulating topography which would result in significant earthworks.
There are additional constructability considerations associated with this improvement strategy due to its interaction with NCN7.
This improvement strategy would likely be the second most expensive.

Based on these key findings, Improvement Strategy 6 is less advantageous than Improvement Strategies 2, 4 and 5. It is therefore recommended that Improvement Strategy 6 is not taken forward for further assessment at DMRB Stage 2.

Assessment of Additional Online Improvements

The assessment of improvement strategies also included a high level assessment of potential additional online improvements within the assessment corridor. The purpose of this high level assessment was to consider the potential impact of the improvement strategies on cross-section consistency within the assessment corridor, with cross-section to be determined at DMRB Stage 2, and potential operational road safety issues.

Various additional online improvements were considered, ranging from targeted safety interventions at existing accident clusters to larger scale improvements that would involve upgrading sections of the existing A75 within the assessment corridor.

It was assessed that additional online improvements would likely impact additional constraints and introduce additional costs as follows:

From an engineering perspective, this would likely consist of additional impacts on properties and accesses, additional earthworks and additional constructability considerations.
From an environmental perspective, any increase in the footprint of the existing A75 has potential to impact on additional environmental receptors such as listed buildings, woodland and other important habitats.

In terms of traffic and economics, while additional online improvements would likely introduce additional costs they would also likely realise additional economic benefits.

Any additional online improvements would likely be implemented as part of Improvement Strategies 2, 3, 4 or 5 as Improvement Strategies 1 and 6 already extend the entire length of the assessment corridor. Therefore, the additional constraints, costs and benefits identified were considered as part of Improvement Strategies 2, 3, 4 and 5.

The outcome of the high level assessment of potential additional online improvements was in line with the assessment of improvement strategies. While additional online improvements could negatively impact Improvement Strategies 2, 4 and 5 from an engineering and environmental perspective, they were still confirmed to be more advantageous than Improvement Strategies 1, 3 and 6. Specifically, when compared to the longer improvement strategies, a shorter improvement strategy with online improvements would likely require less materials, result in less waste and have an overall lesser impact on environmental receptors.

The requirement for potential additional online improvements will be assessed further at DMRB Stage 2.

Summary

The outcomes of the DMRB Stage 1 Assessment are summarised as follows in Table 7‑1.

Table 7‑1: Summary of improvement strategies
Improvement Strategy	Project Objectives	Environment	Engineering	Economics
Improvement Strategy 1	Good	Poor	Poor	Poor
Improvement Strategy 2	Good	Fair	Fair	Fair
Improvement Strategy 3	Poor	Fair	Poor	Poor
Improvement Strategy 4	Good	Good	Good	Fair
Improvement Strategy 5	Good	Fair	Fair	Good
Improvement Strategy 6	Good	Poor	Poor	Fair

Based on these outcomes, it is recommended that Improvement Strategies 2, 4 and 5 are taken forward to DMRB Stage 2 for further assessment.

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