Answer :

Yes. 55mph equals 88.5139 kmph. in 8 hours, you will have traveled slightly over 700 kilometers.
AL2006

Yes indeed !  You sure can. This is your lucky day.

500 kilometers is about  310.7 miles.

In order for you to cover that distance in 8 hours, you only need to average
about  38.8 mph .  If you stop along the way ... for food, gas, rest, pits, etc. ...
then you'll have to drive a little faster to keep up your average.  But by managing
your stops, you can certainly do it without ever exceeding 55 mph.