Out here the land seems to run out of ideas. The Chott el Jerid is a vast salt lake, one of the largest in the Sahara, and the road across it runs on a raised causeway through a landscape that is flat, white and shimmering.
The chott is a dry lake bed for most of the year, a crust of salt and clay over wet mud, and in summer the heat creates mirrors on the surface, so that distant trucks seem to float on water. After rain, shallow pools can form, and the salt takes on pink, green and lilac tints depending on the minerals and bacteria in the water. The crust can be thin and unstable, and tales of vehicles lost off the road have kept visitors on the causeway for generations. The advice is simple: stay on the tarmac and resist walking out to photograph the surface.
Riding here is odd, and a little hypnotic. The road is long and straight, the traffic is light but includes fast trucks and cars, and crosswinds can push a motorcycle sideways, sometimes carrying a fine salt dust that stings the eyes. A closed visor and sunglasses make a surprising difference. The heat is intense in summer, and the lack of shade means that a stop for rest is best taken at one of the small roadside stalls that sell water, soft drinks and souvenirs, among them the crystalline gypsum formations known as desert roses.
The light changes the mood completely. At dawn and in the evening the salt glows pink and gold, and the horizon is a dark line of palms or hills. In midday glare the whole scene turns white and flat, and the sense of distance is difficult to judge, which is a good reason to keep to a steady pace and drink often.
Tozeur lies behind you to the west and Kebili ahead to the east, each of them a town with proper services, so the best plan is to carry water, make sure the tank is comfortable and treat the crossing as a long and strange interlude between oases.