I just drove passed a plant and couldn't stop to see it very clearly : Grows on You

Essex, United Kingdom

I just drove passed a plant and couldn't stop to see it very clearly, it was lovely. It looked like rather a rampant spreading climber as it covered the length of several fence panels. It was smothered in whte pendulous flowers. Had it been later in the year I would have said it could have been a Russian Vine but I think it is a bit early and the flowers were quite long clusters. Anybody any idea what this might be?