Actually, it is, first, because when you pull out to over take it was recognising this as a corner and slowing the vehicle down by between 5mph and 10mph, if you were not quick on the accelerator the vehicle behind in the lane you pulled into would catch you up and then be frustrated that you had pulled out and slowed down. Second, it could frustrate the drivers behind you if ever time you came to a mild bend in the road your car slowed down by 5 to 10mph. Frustrated drivers are riskier drivers. Now that my vehicle drives at a steady speed on these roads I have much less issue with drivers driving up the back of the vehicle and I can concentrate on the manoeuvre rather than the speedo. So yes, unnecessary slowing into corners on roads such as the M6 and the A3 is a hazard and I am well glad its fixed.