In the past two years we have driven a good many miles in those 70-80 mph Western states -- and at 65-68 MPH. not only were we passed by many, we passed our fair share. The only time I recall feeling any sense of danger was one time in Utah that I almost ran over some knucklehead driving his 6 figure class A at 45-50 mph, no signals, in an 80 mph lane. I doubt very much that I held up any interstate traffic, that it could easily get around me if they so desired. Would I prefer to drive along at the flow of traffic speed? Sure, but not in my pickup hauling our 12,000+ pound 5th wheel. So, flashers - not if you are driving 62-65. At 45-50, probably be a good idea