Effects on noise and air quality have been considered for both the construction of the road, and once traffic is using it.
A noise and vibration assessment found that construction noise would be significant but temporary in some locations. Measures to reduce its impact – including hours of working, plant enclosure and temporary noise barriers - have been incorporated into operations and, overall, construction noise is expected to be insignificant.
Once the road opens, nearly 2,400 properties will be affected by increased noise, reducing to around 1,950 once mitigation measures have matured. These include a low-noise surface, cuttings, bunds and three lengths of acoustic barrier.
The effect on air quality during construction and operation is not expected to be significant. Dust control measures will be used during construction, and once open, changes in traffic flows could bring slight reductions in nitrogen dioxide levels in Norwich, with negligible overall effects on particulate concentrations. Norwich City Council is making a number of long-term air quality measurements in key locations around the city. The results, along with further tests, will be used in additional assessments as the scheme progresses.
Carbon emissions are forecast to rise by 0.6% in the first year of opening, but this assessment has not considered the influence of wider Norwich Area Transport Strategy, of which the NDR is a key part.