Proposal for 10 year noise mapping cycle

The Institute of Acoustics (IOA) disagrees with proposals by the Scottish Government to extend cycles for updating noise maps and action plans from five to ten years. The proposal is in a consultation on updating the Environmental Noise (Scotland) Regulations 2006. In responsding our Scottish branch outline the principal functions of strategic noise maps as providing essential evidence for local planning authorities, supporting informed land-use planning and zoning decisions within local development plans. These plans are typically updated on cycles shorter than ten years, so if noise maps are updated less frequently, there is a significant risk that planning decisions will be based on outdated information, potentially leading to inappropriate siting of noise-sensitive developments or insufficient protection of existing communities. Noise maps are also critical in identifying areas significantly affected by transportation and other strategic noise sources, enabling targeted mitigation and action planning. Given traffic flows, vehicle types, infrastructure changes and development patterns can change considerably over a decade, a ten year update cycle risks misrepresenting the current noise exposures of people, with areas potentially being wrongly classified, which could undermine the effectiveness and prioritisation of noise mitigation measures.  Although we accept that an extended cycle would provide greater time for interventions to bed in and be evaluated, moving to a ten-year cycle appears to diverge from the current direction of travel in relation to noise impacts and public health protection, and would risk making Scotland an outlier compared with approaches adopted elsewhere in Europe and the rest of UK.

We also disagree with the proposal to remove the requirement to review strategic noise maps whenever a major development occurs. The maps play a critical role in identifying areas significantly affected by transportation and other strategic noise sources, enabling targeted mitigation and effective action planning, given eg major new transport infrastructure can materially alter local noise environments. Similarly, the proposal for airport operators to be required to produce strategic noise maps and noise action plans (for airports) every ten years is opposed.  Again, over a ten year period, there can be significant changes - in this case to modelling standards and methodologies, aircraft types, flight frequencies etc. In addition, population distribution and land use in areas affected by aircraft noise can change. Overall the proposed changes pose a risk that if noise mapping and action planning are not updated regularly to reflect changes in traffic, land use and populations assessments will become outdated and unreliable, undermining their intended purpose to mitigate the health impacts of noise on populations.

See our full response