BrickED will be the editor integrated into the Logistics: On Rails. It allows to create models that are usable within the game, and as development of the game progresses, more features will be added to further the integration.
BrickED was initially developed for generating sprites for OpenTTD, as such, it has a feature for generating sprites for just about any 2D isometric game out there by rendering a 3D model in a variety of angles. Although some setup may be required for every game.
You can play with BrickED right now, as it is available here: