[cornholio]

There are lots of options still available, one I would think would be to loop it around the stadiums and then take it down Cambie street bridge and loop it back across it back to the stadiums. Would have to close Expo boulevard, Cambie street bridge and 2nd street in the Cambie bridge area but it would be long enough with minimal disruptions to residents and plenty of straight ways with Cambie street bridge being wide enough I think to handle a track in each direction.

The viaducts could also be made use of but that would likely result in more disruptions to residents and require the closer of Main street and pretty much Cambie bridge and cut of the Spectrum towers which would be a no go.

Another option is to make use of false creek by using linked up barges to create a track but that might be too difficult to do(can even use barges for grandstands which would be relatively simple).

Also as Jlousa mentioned BC Place can be used for a loop inside though the entrances might be a bit narrow for two tracks and running it straight through would screw up the straight way along Expo which should be made good use off.

Good thing is that they can make this a yearly event and still design and build the developments in such a way as to allow the event to take place after the area builds up...though im not sure what the developers would say about that(doubt it would benefit their marketing strategy) and im sure there would be some future residents complaining regardless of what they sign off on as far as noise and events in the area go.

Edit: The one that would use Cambie Bridge would be 5.5km in length if it looped around the Stadiums and looped down Quebec with a turn around infront of Science world. On Cambie bridge the track can take the south off ramp across 2nd and loop back up on to the bridge. Lots of locations for grandstands and maybe they can build one up to the bridge height on the city owned land by the Olympic village(next to the bridge).