Main / Road
Road construction is very important in Wurm, it lets you go places - fast. You could make simple paths out of dirt and packed dirt tiles, but those get quickly overtaken by grass and trees. Sand lasts longer, but is slow to walk on. On a paved road you can reach speeds up to 17.28 km/h, compared to the 11 km/h on grass and less than half of that on sand. That in combination with finding your way around - which many seem to have trouble with in Wurm - makes it pretty obvious that roads are a good thing to have.
To make a road level to walk on, so that it does not slope to one side, stand on the higher of the two sides and examine the tile border that crosses the road to the lower side. You will need to do some combination of digging the higher side and dropping dirt on the lower side to bring it to "this slope is level".
In normal grassy areas, it may be possible to simply choose Flatten on each tile as you walk along the road site, you will want to do this before paving as paved tiles cannot be flattened. However, this often does not work because of rock, uneven numbers of dirt, lack of dirt in your inventory or low digging skill. The dig & dump method however will always work, unless there is something preventing dirt from being dropped. It may also be possible that a road has to be placed near a 30+ slope, in which case it is better to flat-raise to level your tile because any dirt dropped will slide down.
When using flatten, one may find it handy to 'stop' the flatten action once the slope hits the desired value, instead of allowing the entire flatten to take place. This can make evening out slopes along a hill much faster.
The optimal road slope is no more than 20; preferably lower for lesser drain on stamina and better visibility ahead. Any slope greater than 20 may physically hurt you if running down the road at full speed. Riding a horse though will allow travelling up and down slopes up to 30 without problems.
On diagonal roads, which are sometimes necessary when building a road on the side of a mountain, the maximum slope should be no more than 14 on all sides.
One-tile wide roads are usually sufficient. For heavily used highways wider designs have been used, for instance to make it easier to guide your horse or cart on auto-run.
As for paving material, gravel roads are easiest to make, because they only require one rock shard per tile to pave. However, they are slower to travel than cobblestone, stone slabs, marble slabs or slate slabs. Cobblestone and stone slabs are equally fast, up to 17.31 km/h walking speed. But stone bricks for cobblestone take much less raw material and effort to create than slabs.
Sand or gravel shoulders alongside the road are popular because they keep trees from growing, increase the visibility against aggressive animals and enemies, and make the road itself more visible for somebody trying to find it. Try to make road shoulders low enough to cross without needing to climb.