This isn't an answer to your question about naming flowers. But I know the feeling of seeing some brilliant roadside planting, and just having to stop to take a photo. I've done that several times.
The first time I did that was several years ago when I passed a traffic island, full of ox-eye daisies, somewhere in South Warwickshire. I also pulled up, about a week ago, to admire and photograph some roadside planting by Coventry City Parks Dept...
There is actually a website devoted to admiring roadside planting. You can send in your photos. They haven't got many photos at the moment. They are also campaigning for more intelligent roadside planting and maintenance.
Try this:
http://www.plantlife.org.uk/roadvergecampaign/3_steps_to_good_road_verge_management
.... Has this been deliberately planted or is it just nature being wonderful?
All of this is man-made. If it's along a major route, then it's the Highways Agency, or for minor routes, the local council. I don't know who is responsible for the A259 (in the first post).