Analysis of speed characteristics for rural two-lane roads: A field study from Minoufiya Governorate, Egypt

This paper presents an analysis into speed characteristics on rural two-lane highways under existing conditions. Empirical data from several study sites on intercity rural two-lane roads in Minoufiya Governorate, Egypt were used in this investigation. Three separate however relevant analyses are presented in this paper. The first analysis investigates the relationship between 85th percentile speed and headway to define a headway value corresponding to free moving vehicles. The second analysis examines the suitability of the posted speed limits on the roads under study. The third and last analysis inspects the conformity of the study sites’ speed data with normal distributions. It was found that the 85th percentile speed took a constant value at headway equal to 5 s or more. Also, a significant proportion of drivers exceed the posted speed limit as well as the current speed limit may not be appropriate. Finally spot speed data follow a normal distribution.