Based on the culmination of many trail rating systems used around the world, the Road Legal 4WD Association has come up with a standard Trail Rating System (TRS) classification for users and trail managers. The Trail Rating System is initially based on a 10 scale for Road Legal Four Wheel Drive vehicles, and our scale gives details to help identify more specifics that we can use to not only inform people with, but also help design trails with. You can expand the 10 scale in increments of 2 past a class 10 so that trails can be designed beyond what Road Legal Four Wheel Drive vehicles are meant for.
This Trail Rating System was carefully designed to be universal so it can be applied to ATV, UTV, Motorcycle, and Non-motorized recreations as well.
Low class trails are easier, the higher the trail class rating, the more difficult the trail is likely to be. Keep in mind however, that ratings may represent the toughest sections, and not the entire trail as a whole.
We designed the Trail Rating System to be freely used among any club who wishes to follow this system. It should be close to what most already use, we just added some black and white numbers to help build trails and take out some of the opinionated critiquing.
Rating Criteria involves a little more than just "what class is this trail?". We rate trails and obstacles (Way points) the same way and an entire trail will be rated to it's most difficult non-passable area. If an obstacle area can be passed, said area will then be rated as a way point on the trail with a separate rating.
Most Stock Road Legal Four Wheel Drives should be able to take up to a class 6 trail with a 33" tire. We highly recommend a winch, closed tow points, rock sliders, under armor, ham radio, and most importantly a buddy or two with their rigs.
Steepness of Grade: Trails with grades are rated by how steep the degree of slope is. Signs and maps will indicate the class and grade as well as arrows as to the direction of the hill (Pitch is up-down / Roll is left-right).
Obstacle Height: Obstacles are measured from ground plane (not underground). Signs may indicate type of obstacle and class. A cluster of obstacles should be measured at their lowest passable pathway. If the obstacle area is able to be bypassed, it is marked on the trail as a way point with a higher class rating.
Trail Depth: Areas of the trail that are below ground plane are measured as part of the TRS. Depths are measured below the ground of the trail which may hold water, mud or be a gully, etc. Signs will include a V and class.
|Class||Pitch/Roll||Obstacle Height / Trail Depth|
|1|| 0-2°||0-5" | 0-12cm|
|2||3-5°||6-10" | 13-25cm|
|3||6-10°||11-15" | 27-38cm|
|4||11-14°||16-20" | 39-50cm|
|5||15-18°||21-25" | 51-63cm|
|6||19-20°||26-30" | 64-76cm|
|7||21-22°||31-35" | 77-88cm|
|8||23-24°||36-40" | 89-101cm|
|9||25-26°||41-45" | 102-114cm|
|10||27-28°||46-50" | 115-127cm|
Trail Width: Narrow trails are measured by width for both turns and straight travel. Vegetation and obstacles can encroach the open area of a trail just as switchbacks and turns can be too tight to make in one pass for the larger 4 door RL4WDs. Trail Width classes are not usually indicated on maps or signs unless an area is a common problem.
Width levels are:
2 Way - Enough room for 2 RL4WDs to pass. 16-24' / 4-7m.
2 Way Single - Enough room for one vehicle on the trail but with room on the side of the trail to pull over and let vehicles go by. 12-16' / 3.6-4.8m.
1 Way indicates a trail that can only be a single direction as there isn't enough room to pass. 8-12' / 2.4-3.5m.
While trail conditions change often, this guide is just that, a guide. We recommend getting training on vehicle and equipment use before going trail riding. Always check your gear before you head out and always let someone know where your going and when you'll return. We recommend the buddy system at all times.
Weather and use can change a trail rating rather quickly. Please be sure to review the trails and way points in our directory. If you find a dependency, let us know so we can address possible issues.
The higher the class level, the more skill and possible equipment you'll need to safely navigate said trails.