Pan-American Highway
The Pan-American Highway is a network of roads stretching across the American continents and measuring about in total length. Except for a rainforest break of approximately , called the Darién Gap, the roads link almost all of the Pacific coastal countries of the Americas in a connected highway system. According to "Guinness World Records", the Pan-American Highway is the world's longest "motorable road". However, because of the Darién Gap, it is not possible to cross between South America and Central America with conventional highway vehicles. Without an all-terrain vehicle, it is necessary to circumnavigate this terrestrial stretch by sea.
Grade (slope)
The steepest roads in the world are Baldwin Street in Dunedin, New Zealand, Ffordd Pen Llech in Harlech, north-west Wales, United Kingdom and Canton Avenue in Pittsburgh, Pennsylvania. The Guinness World Record lists Baldwin Street as the steepest street in the world, with a 35% grade (19°,1 in 3 slope UK) overall and disputed 38% grade (21°) at its steepest section. The Pittsburgh Department of Engineering and Construction recorded a grade of 37% (20°) for Canton Avenue. The street has formed part of a bicycle race since 1983.