Most rural roads outside of urban areas that are not expressways, divided highways or freeways will be 70 km/h zones. This is an decrease from the 100 that exists today on some secondary provincial highways. However I would not use this everywhere. Pretty much only on the one lane per direction non shouldered roads with no barrier between the two directions and only a prohibition on cyclists, pedestrians and mopeds. Don't worry about where they will walk or ride, they would get their own asphalt or concrete paths, between 3 and 4 metres in width (for bidirectional use, one ways would be between 2.2-2.5 metres in width), a maximum speed limit for mopeds at 50 km/h (if you think that is fast, think about the fact that you right now would have to cycle with much heavier flows of much larger and more massive traffic at higher speed), with the right of way over minor side roads (but not at rural roundabouts), but bending out the path so that at least 5-8 metres of width is between the path crossing and the main road crossing, the former of which would be built on a raised table. I take the inspiration for this design from here:https://firstname.lastname@example.org,6.0231271,3a,52.3y,212.46h,80.22t/data=!3m7!1e1!3m5!1ss1-uwIxYe4PRSQ2IVNBLCA!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3Ds1-uwIxYe4PRSQ2IVNBLCA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D45.398132%26pitch%3D0!7i13312!8i6656
In order to feel safe, it would need to have low volumes of motor traffic. This can be done by closing off small sections of roadway, by closing off accesses to main roads, adding speed humps and tables, and adding one way road systems. If it is on a main cycle route, or one frequented, and always at intersections, it would be lit. Intersections are always lit for cars and cyclists and pedestrians, but in other areas, it would generally only apply to the pathway. Cars have very powerful headlights and all the retroreflectivity should work well. Bicycles and pedestrians do not have the power to light up a path on their own. They can only carry lights to make them more visible to others.
People live in the countryside, about a million people in Alberta. They may not live close together, but given the right conditions, people will ride bicycles. It is even more of a concern for safety purposes because of higher speed and volume of traffic. Having only a road shoulder on very busy roads with a rumble strip to protect you is not good protection. It is also a place where you could enjoy the terrain and scenery. Especially in the rural mountain valleys and forests. For some people it could even mean not needing a car. Not everyone will do this, probably not even 5%, even with perfect cycle infrastructure, but even then, that is more people off cars. Velomobiles are very quick, and for much less money than a car, could provide at least somewhat similar transport for things like groceries and school. People will cycle longer distances if they have few enough stops and slows. Remember that not everyone lives in urban areas but all of us deserve choice in how we get from A to B.