By the time I was 12 in 1957 I had traveled Route 66 from Santa Monica to Chicago though not all the way in one trip. It continues to this day. As a child when Dad was driving it was mostly done in MOPARS built from '40 to '57. on our many trips from Texas to California and back the maximum speed limit was mostly 60 except in Arizona where it was 55. Nevada didn't have a maximum speed until the mid to late '70s but it didn't have 66 either. On the trips I remember it was Dad's goal to average 50 mph. That was a tough goal to meet because of lower posted speeds, gas and food stops (the box of fried chicken and boiled eggs eventually ran out) and the fact that you went through every town. The leading industry in many rural areas was traffic tickets so speed limits were obeyed. Sneaky cops were very good at hiding in very remote areas. Dad usually drove straight through with only a little sleep when Mom would drive. None of us slept well when she was driving. I only remember going 70 once when Mom was driving the '57 Dodge. One trip was in a 1950 International farm truck. We did not average 50 mph. It was great because all of those towns were alive back then. The neon lights alone were worth the trip.
Another engineering/safety concern at least on the old Chevys is the caged ball bearings in the front wheels. They were fine for the day but not good for today's higher sustained speeds and wide tires and wheels that create more of a side load.
