The Waitabits is a science fiction short story by Eric Frank Russell.
The survey ship Thunderer sets out to follow up on reports of new inhabitable planets filed by a distinctly laconic advance scout.
They create a strategy of leaving diagrams in the middle of public spaces for the Waitabits to interpret.
An example is that when the first local train passed by the ship, slow as it was it became apparent after about 20 minutes that it was going even slower and was making what to the passengers would be a panic stop.
The Waitabits title listing at the Internet Speculative Fiction Database