Car-Following Models

This overview page collects information regarding car-following models in SUMO. It is still a stub and needs be expanded.

Links

• Publications on car-following models
• How to implement a new car-following model
• More implementation notes on car-following models

Model Parameters

Most car-following models have their own set of parameters. Because some models have a common ancestry they share some parameters. These are described below.

tau

This parameter is intended to model a drivers reaction time (in seconds). It is used by all models. Drivers attempt to maintain a minimum time gap of tau between the rear bumper of their leader and their own front-bumper + minGap. Actually, the reaction time is fundamentally limited by the simulation step size (SUMO option --step-length <FLOAT>). For that reason a value of tau below this step-size may lead to collisions if the leader suddenly starts braking hard. If tau is larger then step-size the situation is safe but drivers will still react during each simulation step (using the currently available models).