I don't know. It really depends on the type of driving, traffic and lay of the land. Most of my everyday (retired) driving is in urban to suburban areas, so speeds over 55 are not common. As Padgett mentioned, there is more than one setting that can be changed, but I took the easy way out and just set the minimum speed to 55. The solution you have now is pretty good and I do believe I will install a lockout switch for special circumstances.