File:UK traffic sign S68.svgDescriptionUK traffic sign S68.svg English: Clean Air Zone (S68, no letter) Date 31 August 2018 (drawing) 27 August 2023 (digitisation) Source Traffic Authorisation
File:UK traffic sign S68c.svgDescriptionUK traffic sign S68c.svg English: Clean Air Zone C (S68, sheet 4) Date 31 August 2018 (drawing) 27 August 2023 (digitisation) Source Traffic Authorisation
File:UK traffic sign S68a.svgDescriptionUK traffic sign S68a.svg English: Clean Air Zone A (S68, sheet 2) Date 31 August 2018 (drawing) 27 August 2023 (digitisation) Source Traffic Authorisation
File:UK traffic sign S68d.svgDescriptionUK traffic sign S68d.svg English: Clean Air Zone D (S68, sheet 5) Date 31 August 2018 (drawing) 27 August 2023 (digitisation) Source Traffic Authorisation
File:UK traffic sign S68b.svgDescriptionUK traffic sign S68b.svg English: Clean Air Zone B (S68, sheet 3) Date 31 August 2018 (drawing) 27 August 2023 (digitisation) Source Traffic Authorisation
