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8 Assessment of Environmental Effects

8.1 Introduction

At present, only CNMAs and CQAs have been identified. These areas may be declared as finalised Noise Management Areas and Quiet Areas at some point. However, it is not yet known what the declaration process will involve. This is currently being considered by Scottish Government legal advisors.

The technical guidance currently being prepared in respect of the Candidate Noise Management and Candidate Quiet Area to actual Noise Management and Quiet Area process will provides further detail in respect of possible interventions. It is therefore impossible at this early stage to identify and assess the likely environmental effects.

Although no formal assessment of environmental effects is possible, in the preparation of this Environmental Report it has been possible to determine the possible interventions in the management of noise.

8.2 Assessment of Noise Reduction Measures

A variety of measures could be adopted to reduce noise from transport. The following list illustrates some of these measures. For each one, a simple matrix has been added, which summarises potential environmental impacts. These are shown in Tables 8.1 to 8.8.

8.2.1 Road Traffic Speed

Noise emissions are a factor of both vehicle speed and type. Generally at lower speeds the engine unit is the main factor in noise generation. However, at higher speeds the road/tyre interaction tends to be the dominant noise source.

Table 8.1 : Speed

8.2.2 Night Time Restrictions

Repeated maximum noise levels associated with pass bys of heavy goods vehicles can potentially result in sleep disturbance within properties situated very close to roads used by heavy goods vehicles during the night time period. Rerouting those vehicles away from noise sensitive areas during night time periods may reduce these effects.

Table 8.2 Night Time Restrictions

8.2.3 Road Traffic Calming

Traffic calming is designed to reduce speed which may in certain circumstances reduce noise. However, poorly designed speed humps and chicanes, together with inappropriate driving style can increase noise as drivers brake and accelerate.

Table 8.3 Road Traffic Calming

8.2.4 Noise Barriers

Should noise barriers be considered as a potential intervention in noise management a number of factors need to be taken into account including the design, cost/benefit and impact on other environmental factors such as visual impact.

Table 8.4 Noise Barriers

8.2.5 Road Surfacing

Measures to maintain and improve the quality of road surfaces can reduce noise. Poorly maintained roads have the potential to be generally noisier. Quieter road surfaces are available but expensive.

Table 8.5 Road Surfacing

8.2.6 Road Traffic Management

Road traffic management schemes may reduce population exposure to traffic noise, for example park and ride schemes, pedestrianisation and car free housing areas. Designing urban streets to encourage slower, smoother driving and ensuring smooth traffic flows may also reduce traffic noise emissions.

Table 8.6 Road Traffic Management

8.2.7 Aircraft

There are international noise standards for aircraft, with an ongoing programme for noise reduction.

Table 8.7 Aircraft

8.2.8 Train Wagons

For trains, newer wagons are quieter, and EU incentives are planned throughout Europe for rail companies to retrofit wagons to reduce noise.

Table 8.8 Train Wagons

8.3 Mitigation

8.3.1 Introduction

There is a statutory requirement under the Scotland SEA Act 2005 for the responsible authority to demonstrate how measures to prevent, reduce or offset any adverse effects identified from the assessment have been incorporated into the plan. The recognised approach to mitigating adverse effects often relates to changes being made to the overall plan or to the policies or actions included within the plan. These measures tend to include:

• Changes to the wording of the plan, policy or proposal
• Removal of a policy or proposal
• Addition of new policies or proposals
• Devising new alternatives, possibly a combination of the best aspects of existing alternatives
• Identifying issues to be considered as part of the design and implementation of specific developments/activities associated with the plan
• Identifying issues to be considered in the Environmental Impact Assessment ( EIA) of specific developments/activities

For the above approach to mitigation to be effective there must be sufficient detail contained within the plan that is being assessed to enable the policies, proposals or actions to be clearly identified and amended accordingly. In terms of the NAPs, the aim of the consultation document upon which this SEA is based, is to set out the proposed structure and content of the NAPs.

As previously discussed, the NAPs do not set out specific interventions or developments. The NAPs identify CNMAs and CQAs. In approximately 2 years and following further analysis, the final NMAs and QAs will be declared. From that stage, physical interventions will be identified and the process of declaration of NMAs and CQAs will address potential conflicts with existing plans, policies and initiatives in terms of environmental effects. This will be included within the technical guidance currently being prepared in respect of the Candidate Noise Management and Candidate Quiet Area to actual Noise Management and Quiet Area process. Mitigation measures will be assessed at this juncture to ensure that all environmental factors are considered.

This highlights the importance of monitoring the implementation of plan as set out in Chapter 9.

8.3.2 Approach to Mitigation

In terms of this SEA the main focus for mitigation is to identify measures to prevent, reduce or offset the potential negative effects identified as part of the assessment of the individual policy areas and the overall NAPs. This will be achieved by identifying measures that could be integrated into the overall design of a policy area/or the wider NAPs and future technical guidance to ensure that the main functions of that policy area and the delivery of those functions do not have an adverse effect on the environment.

In order to ensure that mitigation measures are implemented (and remain relevant) it will be necessary to monitor the implementation of the plan at all key stages. The approach to mitigation is therefore directly linked to the approach to monitoring set out in Chapter 9.

8.3.3 Mitigation Measures

The SEA results have identified that overall, the NAPs are likely to have a positive effect on the noise environment. However, there are some areas where the NAPs or the main functions/actions could have negative effects on the environment. These effects include:

• Direct effects of the NAPs on a specific SEA topic
• Possible unknown effects. These relate to the element of risk or uncertainty associated with changes/introduction of policies or actions which could have unintended consequences. For example the NAPs may identify a NMA which is already covered by an Air Quality Management area; it is important that integrated policies are introduced whenever possible.

8.3.4 Mitigation Measures

Table 8.9 below sets out the possible options for mitigating and enhancing the NAPs based on the results from the SEA.

Table 8.9 Mitigation Strategy

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