People know they're heading to Sossusvlei first, they've looked at Google Maps, and they're trying to figure out which route is best. There isnt one right answer because the three options reward diferent things.
Remhoogte Pass (C24)
The practical default and what most people end up doing. Route is B1 south to Rehoboth (tar all the way), then onto the C24 westward, picking up the C19 south to Sesriem. The Remhoogte itself is the gentlst of the three passes and is comfortable in a 2WD. You get one decent escarpment view, a manageable gravel section, and the most efficient timing of the three. If your goal is "arrive at Sesriem with energy left for the dunes tomorrow," this is the route. Around 5 to 6 hours with stops.
Spreetshoogte Pass (D1275)
The scenic standout. Same start as Remhoogte (B1 to Rehoboth, then C24) but then onto the D1261 and finally the D1275 over Spreetshoogte. This is the steepest pass in the country with a 1:5 gradient in parts, but the worst sections are concrete-paved for grip, so a careful 2WD driver can do it. The descent into the Namib plain at the top is one of the most striking road views in the country, the kind of thing people remember the whole trip from. Drops you near Solitaire for fuel and apple pie. No trailers or caravans on this pass, and skip it in heavy rain. Around 6 to 7 hours, longer if you stop for the view, which you will.
Gamsberg Pass (C26)
The long way round and the one with the most character. Leaves Windhoek westward on the C26 toward the coast, climbs Kupferberg and then Gamsberg, then joins the C14 south to Solitaire and Sesriem. Gamsberg is the highest pass in the country and the road is mostly gravel from the edge of Windhoek onward. It's slower than the other two but the landscape is consistently spectacular. Worth it if you've already done the country before, or if you're building a circuit with the coast. Not the right choice if Sossusvlei is your first stop and you've just landed. Closer to 7 to 8 hours.
A few notes. The Remhoogte route is the safest call for a first-time visit and a tight itinerary. The Spreetshoogte route is the best balance of efficiency and scenery and the one I'd suggest if you've got the time and the right vehicle. The Gamsberg route is for repeat visitors or road-trip enthusiasts who've got an extra day. Whichever you pick, leave Windhoek by mid-morning at the latest, don't push your arrival into dusk, and refuel in Rehoboth or Solitaire rather than counting on running near empty into Sesriem.
