I contend the illegality exists because the following paragraphs in Chapter 3 of Traffic Signs Manual have been totally ignored by Coventry City Council viz., Para 13, (13.2) states: 'Restricted Parking Zones are therefore suitable only for single streets or clearly defined small areas.' and Para 13, (13.8) states: 'At any time' signs are needed as there are no double yellow signs within the zone.
But see SADC, ROAD TRAFFIC SIGNS MANUAL (3d ed., 1999) available at http://www.transport.gov.za/ library/index.html (click on "Legislation, Road Traffic") [hereinafter SADC SIGN MANUAL] (providing SADC suggestions on specific road signs).