The 'most sensible' option would be to plan for more reasonable speeds of a traditional draft animal canal network. Humans can move a huge volume of material in a timely fashion even if only heading along at little more than a walking pace of draft animals towing a narrow boat.
However that's been done and is obviously boring, so...
If our goal is to establish reliable and speedy transport of large volumes of goods and materials without readily falling into building railroads, then we have a relatively simple option if we can stomach the cost...
Flash Lock Stairs:
https://en.wikipedia.org/wiki/Flash_lock
If our society is in a location that can provide enough sources of water then we can harness that flow of water directly. Effectively we are building/rebuilding rivers in a controlled manner, then punting barges out into them to float down the line.
How fast we can allow them to go will depend on how much water we have on hand, how much engineering we're willing to invest, and possibly how brave your crews are... As we're basically building giant and stupidly long log flumes.
Quick travel is of course a one-way deal unless we want to get really creative with lock design, but otherwise we can overcome that with good loop designs. 87
'Flow' from point A to B down one stretch of canal, then ascend a lock-stair and flow back from B to A [Or from B to C, then another run from C to A] on a different canal.
To avoid excessive wear on the canals and improve control, you would likely want to have many very shallow 'steps', and probably send boats down in groups/trains. Skilled lock operators can then open and close their locks in series to maintain and control the speed of the boats, and ensure water levels don't drop too far in any given part of the system.
As a bonus you also naturally end up with stations potentially well suited for optical-telegraph... As each lock probably wants to be setup such that they can see the previous one so they can open or close as needed.
https://en.wikipedia.org/wiki/Optical_telegraph
Geography wise, such a system would likely work best for a nation which has a long and relatively narrow section of moderately level land that fronts many long mountain/highland valleys that get plenty of rain. Your society is going to need to be experts at designing aqueducts and canals. 87