Before each hike I find myself researching for hours if there are any exposed parts of the trail where I might have to turn around. Unfortunately, the common color grading (blue, red, black) can refer to slope, fitness level, path conditions or all three of them. Since I like steep trails with high altitude differences, but suffer from vertigo at the exposed parts, I always had difficulties to find the right trail with the common color grading.
On our site, all trails are marked with the color grading defined below. Please note that each person suffering from vertigo has a different sensibility to slope and exposure. A trail that is fine for me might be impossible to walk for others.
Over the years, I found another method that works pretty good for me. Some online maps also show the gradient of the slope. It takes some time to find out which gradient is still fine for you (for me it is everything below 35°). But once you found your personal gradient limit, researching the feasibility of the hike gets pretty easy.
Grade 1: No exposed parts, trail is mainly flat.
Grade 2: No exposed parts, trail is uphill / downhill. Therefore, some people may already suffer from vertigo.
Grade 3: Some short parts of the trail may be exposed but the trail is broad or secured with a fence.
Grade 4: Some short parts of the trail are exposed, the trail is narrow. The trail may be secured with a rope.
Grade 5: Many parts of the trail are exposed, the trail is narrow. The trail may be secured with a rope. Climbing may be necessary.