Based on the driver's individual difference of the driver's perception ability, we in this paper develop a new fundamental diagram with the driver's perceived error and speed deviation difference. The analytical and numerical results show that the speeddensity and flow-density data are divided into three prominent regions. In the first region, the speeddensity and flow-density data are scattered around the equilibrium speed-density and flow-density curves of the classical fundamental diagram theory, where the widths of these scattered data are very narrow and slightly increase with the real density (i.e., the scattered data appear as two thicker lines); the running speed is approximately equal to the free flow speed and the real flow approximately linearly increases with the real density. In the second region, the speeddensity and flow-density data are scattered widely in a two-dimensional region, but the shapes of these widely scattered data are related to the properties of T. Tang ( ) ·