Road Building tool for UK/Irish roads

Hi guys just wondering if anyone knows of a road building tool that allows for the building of roads but for the UK and Ireland? Here we drive on the left side of the road and we use roundabouts where intersections would normally be used. I have tried road architect but from what I can see it only supports the american road system https://www.assetstore.unity3d.com/en/#!/content/15739 .

Thanks in advance.