Cardiff’s Castle Street is set to remain open to general traffic

Cardiff’s Castle Street looks set to remain open to general traffic with the current temporary road set up made permanent – with two lanes for general traffic, a westbound bus lane and a two-way cycleway remaining on the street.

Cardiff Council’s Cabinet will discuss two options at its meeting on Thursday April 20th – with a recommendation, subject to Welsh Government funding, to allow general traffic to continue to use Castle Street and to enable a permanent scheme to be put in place.

Option 1. To allow general traffic to continue to use the street;

Option 2. Only to allow buses, taxis, and cyclists to use the street.

Detailed air quality modelling has now taken place for Castle Street and the surrounding network for both options and the results show that keeping the road open to general traffic is preferable both in terms of the benefits to the economy and the environment.

The air quality modelling has resulted in three main conclusions:

1. Both options achieve the legally required air quality on Castle Street.
2. Banning general traffic on Castle Street would create an increase in Nitrogen Dioxide (NO2) concentrations on the wider road network.
3. Allowing general traffic to use Castle Street will provide more resilience on Cardiff’s highway network as the city continues to develop.

Both options meet the Welsh Government requirements to deliver air quality compliance – measured levels of Nitrogen Dioxide (NO2) on Castle Street have been compliant since 2021 following legal direction from Welsh Government to reduce the levels of NO2 on this street.

Cllr Dan De’Ath, Cabinet Member for Strategic Planning and Transport said: “The modelled data shows that allowing all traffic to use Castle Street does marginally improve the overall air quality in the city centre and the surrounding road network. When transport planning, we must ensure that there are adequate routes from the east of the city to the west and vice versa, not only for motorists, but for cyclists and pedestrians as well.

“Also, keeping Castle Street open to general traffic will help traffic continue to flow into and out of the city centre in the future when we consider other road calming measures. For instance, we know that we will have to look at restricting the east to west route via Callaghan Square where traffic lanes will need to be removed to allow the new on street tram/train line to be built for the first phase of Cardiff Crossrail. This is an exciting project which will really begin to change the public transport offer across the city. Continuing to allow all traffic to use Castle Street will help traffic to flow better into and out of the city centre while our tram/train options progress.

“Other requirements must also be assessed other than air quality, we need to consider the impact of any change on any road layout on the wider highway network; we must protect residential areas from air pollution; support cycling and walking and install a permanent scheme on Castle Street that befits a capital city. At the end of the day, we must improve the local environment for everyone.

“If Cabinet approves, the temporary scheme that is currently in place will be made permanent with two lanes for general traffic, a bus lane westbound, a two-way segregated cycleway and wider pavements. Subject to Welsh Government funding, and following the necessary tender processes, work could start on-street in early 2024.”

The temporary scheme that is currently on-street is the original design that was set out in Cardiff’s Clean Air Plan in 2020 and was approved by Welsh Government before the COVID Pandemic began.

Since then, the road was temporarily closed when lockdown restrictions were eased to build an alfresco dining area to help the hospitality trade.

Following a public consultation Castle Street was re-opened to general traffic in June 2021 with 53.8% in favour, and 33.8% opposed. Since then, detailed air quality and traffic modelling has taken place and the results of this modelling will be presented to Cardiff Council’s Cabinet.

Following the legal direction that was issued by Welsh Government, the council did act in the quickest time possible to reduce the levels of NO2 from 44 µg/m3 in 2019 to 33 µg/m3 in 2022. Since 2020 the air quality on Castle Street has been compliant with all air quality legislation.