We present a macroscopic traffic flow model that extends existing fluid-like
models by an additional term containing the second derivative of the safe
velocity. Two qualitatively different shapes of the safe velocity are explored:
a conventional Fermi-type function and a function exhibiting a plateau at
intermediate densities. The suggested model shows an extremely rich dynamical
behaviour and shows many features found in real-world traffic data.Comment: submitted to Phys. Rev.
