Many skiers and snowshoers experienced difficulty parking on the Chance Creek FSR during winter 2007/2008. There was a lot of competition for parking spaces with the road also being heavily used by snowmobilers. Apparently the area right on the highway is to be used only for emergencies and chaining up (no parking) and the area just across the bridge and railway tracks is no-parking as well because it is inside the Barrier hazard area below Garibaldi Lake.
It looks like the road will be signed as no parking up to the 400m elevation level (before the catski base). The Varsity Outdoor Club has negotiated with Powder Mountain Catskiing (PMC) for parking for a small number of non-motorized parties at their base area. Call PMC in advance for the combinaton to the gate key lockbox. See their website for contact info.