Hey Ed, what do you know about the Blackburn/Carnegie winter road races at Lang Lang, Crib Point, etc?

http://www.carnegiecycling.com.au/index.php?c=Calendar

If the race is 80 to 100km, are they usually a few laps of a 20 or 30km circuit, or 1 lap, or what?

I take it by the Lang Lang lay out that it's one lap, but I thought they were usually a circuit