Ryan Harden

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Universal Trail Rating System

The Road Legal 4WD Association has come up with a standard trail rating system for drivers and trail managers to use. It is based on the 10 scale setup that many clubs use, but 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.

Low-level trails are easier, the higher the trail rating, the more difficult the trail may be.

We designed the 4WD TRS 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 level is this trail?". We rate trails and obstacles (Waypoints) the same way and an entire trail will be rated to it's most difficult or impassable area. If an obstacle area can be passed, said area will then be rated as a waypoint on the trail. 

Steepness of Grade - Trails with grades are rated by how steep the degree of slope is. Signs and maps will indicate the level of the hill based on either pitch (front to back) or roll (side to side) in degrees measured using an inclinometer/clinometer. Most vehicles are at a greater risk of rollover past 20° roll and aftermarket lifts and tires can increase hill instability. Talk with your dealers, trail guides and get training to become more comfortable with traversing hills. If the hill feels too steep, it probably is, even if your vehicle can do it, know your limits as a driver. It takes a lot of practice to safely maneuver over/on hills. 

​Level 1 Grade  ​0-5°
​​Level 2 Grade ​6-10°
​​​Level 3 Grade​11-15°
​​​Level 4 Grade​16-20°
​​​Level 5 Grade​21-25°
​​​Level 6 Grade​26-30°
​​​Level 7 Grade​31-35°
​​​Level 8 Grade​36-40°
​​​Level 9 Grade​41- 45°
​​​Level 10 Grade​over 46°

Obstacle Height -  Obstacles are measured from ground plane (not underground). Signs may indicate the type of obstacle and level. 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 waypoint. Observe your vehicles obstacle approach and departure angles as well as its break-over angle to avoid damage while crawling on Obstacles. Obstacle levels are:

​​​​Level 1 Obstacle ​0-5" / 0-12cm
​​​​​Level 2 Obstacle ​6-10" / 13-25cm
​​​​​Level 3 Obstacle​11-15" / 27-38cm
​​​​​Level 4 Obstacle​16-20" / 39-50cm
​​​​​Level 5 Obstacle​21-25" / 51-63cm
​​​​​Level 6 Obstacle​26-30" / 64-76cm
​​​​​Level 7 Obstacle​31-35" / 77-88cm
​​​​​Level 8 Obstacle​36-40" / 89-101cm
​​​​​Level 9 Obstacle​41-47" / 102-114cm
​​​​​Level 10 Obstacle​48+" / 115+cm

Trail Depth -​ Areas of the trail that are below ground plane are measured as part of the TRS. Depths are measured below the level of the trail which may hold water, mud or be a gully, etc. Signs will include a V and level. Depth levels are:

​​​​​​Trail Depth Level 1 ​0-5" / 0-12cm
​Trail Depth Level 2 ​6-10" / 13-25cm
​Trail Depth Level 3​11-15" / 27-38cm
​Trail Depth Level 4​16-20" / 39-50cm
​Trail Depth Level 5​21-25" / 51-63cm
​Trail Depth Level 6​26-30" / 64-76cm
​Trail Depth Level 7​31-35" / 77-88cm
​Trail Depth Level 8​36-40" / 89-101cm
​Trail Depth Level 9​41-45" / 102-114cm
​Trail Depth Level 10​46+" / 115+cm

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 levels are not usually indicated on maps or signs unless an area is a common problem. Width levels are:

2 WayWide ​Enough room for 2 RL4WDs to pass. 16-24' / 4-7m.
2 Way Narrow ​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.
Single Vehicle Limited Passing​Areas where passing is only possible in select areas. These areas may be marked on the map. 
​​Single Vehicle No Passing​Indicates a trail that can only be a single direction as there isn't enough room to pass. 8-12' / 2.4-3.5m.
​Turning Radius ​​
Tight for 2 DoorThese trails are very tight and not advised for larger/4 door vehicles. A trail that falls into this category will not fit a 4 door or larger RL4WD. 
​Tight for 4 Door​These trails mean 4 Door RL4WDs will not clear corners without backing up or related maneuvers
Acceptable for most RL4WDs​Wide trails or overlanding roads will fit into this category. These indications are not usually on any signs, they are only listed in the directory. 

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.

Most stock RLWD's can navigate over 1-3 level trails in some fashion. Weather and use can change a trail rating rather quickly. Please be sure to review the trails and waypoints in our directory. If you find a dependency, let us know so we can address possible issues.

The higher the level, the more skill and possible equipment you'll need to safely navigate said trails.

In the next page we're going to list the equipment and gear you may want to consider before going off of paved surfaces. 

RL4WD Evolution, GeoCrawls, Trail Signs, Rating Sy...
More Wisconsin Progress 8/10/2018