According to the Denzel Alpine Road Scale , all of the mountain pass and mountain roads listed, including old, gravel and poorly preserved military roads, are divided into levels of driving difficulty in the Great Alpine Road Guide from Denzel-Verlag . Various factors such as route, surface, width, edge protection, inclines and slopes, absolute and relative height, etc. were used for the overall assessment. The basically vehicle-independent scale comprises five basic grades SG 1 to SG 5 and four intermediate grades (for example SG 3–4).
This scale is also often used outside the Alps to summarize the technical driving requirements of a route as a guide for travel planning.
sufficiently wide hairpin bends with a barely noticeable slope in the turning plates
Gradients up to max. 15%
suitable for all types of cars
suitable for all types of motorcycles
suitable for all types of bicycles with gearshifts suitable for mountain use
SG 3
The route requires practice and safe driving technique on mountain roads.
mostly just two lanes, in sections one lane with dodging
Partly or completely missing asphalt pavement, poor condition
Edge protection is largely missing
many, strongly curved bends, tight hairpin bends with steep slopes
over longer distances more than 15% incline
Only restricted access for sports cars
No longer suitable for cars with trailers (especially caravans) and trucks over 3.5 t total weight and are mostly prohibited by appropriate signs
Only restricted access for sports motorcycles
Usually unsuitable for racing bikes, at most possible with wider tires, gearshift adapted to steep gradients
SG 4
Even for those who are used to the mountains, difficult routes require driving skills that are well above average.
mostly single lane, few passages
hardly maintained road; z. Partly coarse gravel, heavily washed out or extended, side slopes possible, is slippery when wet (mud, grass), possible bottlenecks due to mudslides, passable fords
Except for a few dangerous places, no edge protection
very narrow, not developed hairpin bends, forced reversing for middle class cars
steep gradients, e.g. Sometimes at heights with thin air (over 2000 m)
Recommended for off-road vehicles, rough tire tread
for enduros, to a limited extent still for touring motorcycles with sufficient ground clearance, rough tire tread recommended
for mountain bikes, to a limited extent also for trekking and touring bikes, rough tire tread recommended, gearshift adapted to steep inclines
SG 5
Very difficult and dangerous route, use at your own risk!
hardly any roadway, on the border to the terrain
hardly recognizable road maintenance, coarse gravel, bare rock, sand, mud; Dangerous bottlenecks, high risk of falling rocks, heavy leaching, mudslides and side slopes, temporarily impassable fords (depending on the weather and season)
Completely unsecured side edges, also ridge sections exposed on both sides, heavily exposed
not always recognizable route
extreme gradients, even at altitudes over 2000 m
only for off-road professionals with appropriate vehicles
only all-wheel-drive cars with large ground clearance and adapted tires
only enduros and cross machines, with strong reservations possibly also touring enduros, long suspension travel, a lot of ground clearance and adapted tires
Mountain bikes only, adapted tires, gearshift adapted to steep gradients
