If you drive on the M50 then you should probably know what these black and yellow signs mean...

Have you spotted these mysterious black and yellow signs placed on roads near the M50? The vulnerability of the Dublin ringroad was exposed recently when a crash shut one side of it for about seven hours and motorists were helplessly stranded for long periods. A new group involving gardai and Dublin Fire Brigade has devised alternative traffic routes in the event of a full closure of the M50. The routes are marked with permanent signs mounted on existing road signs (below). A spokesman for Transport Infrastructure Ireland said: “These diversion routes are intended to be the best available alternative routes which will alleviate but not eliminate the disruption arising from major incidents, particularly at times of peak traffic.” He added: “Each route will be indicated by a symbol attached to existing signs and diversions will be initiated by means of existing [ELECTRONIC]variable message signs located on the M50.” The Interagency Incident Coordination Group involves An Garda Síochána, Dublin Fire Brigade, Transport Infrastructure Ireland and the Motorway Traffic Control Centre as well as the four Dublin local authorities.