Questions about cell details and targeted size of the world


here are some more questions, regarding the exact behavior of the trains as well as the targeted size of the flatland.

  1. Do each trains have a defined departure time? If yes, can they depart to the target destination cell before the defined departure time, or do they need to wait in an adjacent cell?
  2. Do the stations mean a dead end cell always, or can the stations be in the middle of a railway?
  3. In case of a “Double slip switch”, can two trains turn simultaneously? See attached picture: t1,t2,t3 are consecutive timesteps.
  4. Can we have information about the size of the maps, and the number of agents?

Hi Marc-Oliver

Thanks for the great questions. Here are some short answers:

  1. In this challenge all trains have the same departure time. All agents depart when the first env.step() is executed. This will only change in future challenges and versions of flatland
  2. Stations can be in any cell. They are often chosen in dead-end cells for feasibility. If an agent enters its station it cannot move anymore. Thus station in the middle of lines will block the line once the agent reaches the station.
  3. A cell capacity is equal to one. This means there can never be more than one train at a given cell!
  4. For scoring the submissions there will be a max_size and a max_nr_agents. Current estimates will be a max_size = 100x100 with max_nr_agent=100. This can however still change as we are running tests now.

Hope this infromation helps.

Best regards,

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