Trucks not needing roads was actually our "feature". You just build things and logistics network will figure things out. This goes hand-in-hand with the free-form mining (also our big feature), since that would be impossible to do with roads.
However, we do hear many people wanting roads, especially later on, it is on our list of potential additions.
Vehicles having no collisions is a technical limitation. Path-finding on dynamic terrain on a large grid, with constraints on vehicle size (small trucks fit under some buildings, large excavators wont) is just too hard to solve with vehicle avoidance. Even with local avoidance vehicles would get stuck too much. One-way roads are probably the answer. Maybe some best-effort local avoidance could be done to minimize it.
PS: I have rewritten the path-finding code 3 times. It's quite complex...
I like that you actually mine the stuff in the style of mines you use and the stuff is getting removed visually.
What i find disappointing is the trucks/vehicles not needing any streets. I'm not sure if it would make the game more interesting or not though but that i have to build a bridge over a pipe for the trucks but the trucks just drive through each other... not liking it :D