Hi JimInMichigan,
A few years back the wife and i took that route on our way to Colorado, i believe speed limit is 75 and if you stay in the right lane keeping it around 62 to 65 is going to be fairly safe. when you go through big city areas if its heavy traffig then there might be police watching but if you aren't impeding traffic i doubt they will bother you.
When we made our trip I would only run 58 when the wife wasn't watching because when it was her time to drive she has a hard time keeping it under 70 LOL Have a safe trip with what ever speed you decide.
thanks for reading,
Don
__________________________________________
View my fuel log 2015 Mirage Es 1.2 manual: 58.0 mpg (US) ... 24.7 km/L ... 4.1 L/100 km ... 69.6 mpg (Imp)