He was on his way to a meeting in Pembrokeshire when he noticed the woman dangerously close to traffic.
Coleman is said to have driven around Haverfordwest for half an hour to see if the woman could recognise her home, before calling friends in the town to ask for help.
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A petition will be handed in at the Senedd later calling for rules to prevent the use by under 13's in care of social media sites.
Technology projects that promote the Welsh language are to get over £250,000 of funding to help encourage more use of in digital media.
A chilly start to the day is expected but prolonged spells of sunshine will allow the temperatures to respond, highs of between 14 - 17 °C