Things I Learned Doing Trail Work
A good trail sheds water quickly.
Know these terms well: Grade Reversals, Knicks, Rolling Grade Dips, Waterbars, Outsloped Tread
A trail that doesn't shed water is a lot of work.
In some situations, it is not possible to get the water off the trail without realignment of the trail. For example, a trail in a deep gully will always collect and hold water. The solution for a lasting but high maintenance trail is to build structures to either slow the water or reinforce the tread.
It is difficult to make all trail users happy on multi use trails.
A rock too big to move weighs more than my truck unless I am going downhill.
Trail work requires creativity and an understanding of physics. With simple tools, any object can be moved. A rockbar(lever) and a couple straight, round logs(wheels) can make the job easier. A rockbar properly placed can have a mechanical advantage of 30. A 150lb force exerted on the end of this lever will produce a force of 4500 lbs. My truck is 4000 lbs.
Old trails are rarely designed.
It is my experience that many trails originally followed game trails or a path created through use. In both cases, do not expect the trail to have many grade reversals or a consistent design. For example, many trails go up ridgelines since that is where users will naturally go if not trail is present. However, ridgeline trails are difficult to get the water off without the construction of structures.
The grade of the trail should always be less than half the sideslope grade.
A trail with a grade that is equal to the slope of the surrounding terrain is the quickest way down the hill and inevitably where water will go. A trail with a grade that is half of the sideslope will shed some of the water. See the pattern?