First, considering the transfer limitations of belts, the maximum amount of resources from a single truck station is limited to the maximum belt speed, at the time of this writing 450 items/min. The inputs and outputs of truck stations could be configurable to allow either or both to be inputs or outputs. Alternatively a new station could be implemented at a higher tier research to allow mass, multi-item resource transfer.
Second, would be be the ability to construct roads. Roads would be single lane or merge-able to multi-lane, constructed similar to belts while following the average contour of the ground. Resources used in construction would be asphalt or some combination of raw oil, coal, concrete, iron rods, steel beams, or encased industrial beams. A point-to-point bridge constructing method would likely be desirable as well, perhaps using the reinforced modular frames.
An additional idea regarding a paved road is to be able to link vehicles to follow a lane and only require path recording at either end, pick up and drop off. This would necessitate a better menu to manage pathing. I am not a fan of the radial in this instance.