Can you visit Salar de Uyuni without a tour guide?

Driving out to the edge of Salar de Uyuni on your own is technically feasible, but going into the interior without a licensed local guide is strongly discouraged and also extremely risky.

It covers more than 10,000 square kilometres, yet there are no usable roads, no signposts, and no reliable cellular reception. Everything stays so flat, and the white horizon blends together, that optical tricks are common, and then it gets very easy to lose your bearings. Also, in the rainy season, the salt crust can turn into a thin, weak surface in certain stretches, so one wrong move can become serious. With a licensed operator, you get the exact route knowledge, plus they bring the required emergency gear.