A new time-stepping strategy and boundary treatment to improve recent 2d traffic model

We show how a recently published 2d model for traffic flow can be further improved. Besides other improvements and simplifications, we present not only a method to compute the necessary time step restrictions, but also a subcycling for the inflow and outflow. This drastically reduces computational cost on large domains with coarse grids, i.,e.\ for simulations of a whole region instead of a small part of a city or town.