I'm a big fan of laying out street circuits, but this doesn't seem to be popular here. So, I'll take a stab at a road course.
After a 45-year break, the Canadian Grand Prix is returning to Mont Tremblant. How unfortunate it is, though, that the Riviere du Diable has decided to flood the eastern portion of the circuit. This blue line indicates what remains of the track:
http://www.gmap-pedometer.com/?r=6765683
Your task is to layout a new circuit, using as much of the original as possible, so that racing can continue at this location. Minimum length shall be 4.0km. The area eligible for your layout is shown within these boundaries:
http://www.gmap-pedometer.com/?r=6765686
You have a pretty healthy budget, considering all the insurance money you just got, but you don't have a lot of time for construction. Anything goes so long as the remaining track is incorporated into your design. I'll announce a winner at Noon EST on Thursday!