IROS 2026 races four cars on the track at the same time, so it is worth practising against more than one opponent well before you travel. Multi-car support is on the dev-humble branch of f1tenth_gym_ros.

Number of cars

Set the number of cars with num_agent, either in config/sim.yaml or directly at launch:

ros2 launch f1tenth_gym_ros gym_bridge_launch.py num_agent:=4

Driving the opponents

The first car is the ego, the rest are opponents. Each opponent gets its own topics (/opp_drive, /opp_drive2, …), and a car only moves when you publish to its drive topic — an opponent you never command will simply sit on the grid.

Start poses

Every car needs a start pose in the config (sx1/sy1/stheta1, …). The shipped sim.yaml already defines four, so num_agent:=4 works out of the box. Define more poses to run more cars.

Full documentation

Full instructions are in the repository README.