I can neither speak for Jawja nor England, but the Texas traffic code states that any vehicle traveling at 10% below the posted speed limit on a public roadway can be, at the LEO's discretion, cited for impeding traffic flow. Also, traffic code prohibits mopeds, small scooters, and similar under-powered machines, from riding the Interstate highways; where some of us Texans take advantage of our 85mph speed limits.
Sorry for your situation, Marc. I wish you good fortune with da Judge.