The concentration of nitrogen dioxide at the Park Street Air Quality Management Area continues to exceed targets according to an annual update report (pdf).
In 2023, three monitoring stations along Park Street exceeded the national target of 40μg/m3 of nitrogen dioxide – but only narrowly.
The trend since the introduction of the Air Quality Management Area in 2019 is a gradual fall in emissions – by as much as 22% in some cases.
BCBC believe this is due to improved traffic flows since upgrades to the Angel Street and Broadlands junction traffic lights, as well as the introduction of a right turn lane onto Heol-y-Nant as part of the housing development at the former Ysgol Bryn Castell.
The expected impact of the new 20mph speed limit along Park Street on air quality wasn’t mentioned – though this will likely be reflected in future reports.
As reported earlier this year, BCBC has paused a proposal to limit access to St Leonard’s Road. This is because they expect nitrogen dioxide levels to fall below limits by 2026-27, making the measure redundant.
