The **design speed of a road** is the maximum safe speed that can be maintained on a road under favorable conditions. This speed is determined by considering the type of road and its specific conditions, as mentioned in the speed limits established for different types of roads. For example, on highways and expressways, the maximum allowed speed is 120 kilometers per hour, which reflects the design speed for those roads.


The design speed is crucial to ensure that vehicles can travel safely, easily, and comfortably. Unlike the appropriate speed, which adjusts to weather, road, vehicle, and driver conditions, the design speed is a fixed standard based on the road's infrastructure.