Most of the road is three lanes, with two lanes for uphill traffic on each side of the hill, and a passing lane for southbound traffic on a relatively flat alignment near the summit. The highway is sometimes closed by snow in winter.
This passage describes a highway with a specific configuration: three lanes, two lanes for uphill traffic on each side of a hill, and a passing lane for southbound traffic on a flatter section near the peak. It also mentions that the highway may be closed due to snow in winter.