Unless otherwise posted, the speed limit in Riyadh is 50 km/h (30 mph) in highly-populated areas, 70 km/h (43 mph) on urban highways, and 120 km/h (75 mph) on national highways. Driving beyond the posted speed limit may attract hefty fines or penalties. You should always watch out for posted speed limits and signs on different roads. Road signs in Riyad are bilingual in Arabic and English. Dust storms are common in Riyadh, so you should slow down or observe caution when driving during these conditions. Search rental cars on KAYAK