In the United States, maximum grade for Federally funded highways is specified in a design table based on terrain and design speeds, with up to 6% generally allowed in mountainous areas and hilly urban areas with exceptions for up to 7% grades on mountainous roads with speed limits below 60 mph (95 km/h). The lateral slopes of a highway geometry are sometimes called fills or cuts where these techniques have been used to create them. The highest grade a vehicle can ascend while maintaining a particular speed is sometimes termed that vehicle's "gradeability" (or, less often, "grade ability"). Trains typically rate much lower than automobiles. In vehicular engineering, various land-based designs ( automobiles, sport utility vehicles, trucks, trains, etc.) are rated for their ability to ascend terrain. Paris–Bordeaux railway, except for the rampe de Guillervalīrunel's Billiard Table - Didcot to Swindonīrunel's Billiard Table - Paddington to Didcot
The long drag on the Settle & Carlisle line Mount Washington Cog Railway (maximum grade) Lynton and Lynmouth Cliff Railway ( funicular railway) The examples show round numbers in one or more of the notations and some documented and reasonably well known instances.Įxamples of slopes in the various notations
For ratios, larger numbers n of 1 in n are shallower, easier slopes.