Dangerous Roads Around The World

• Roughness - Deviations from a true planar pavement surface, which affects vehicle suspension deflection, dynamic loading, ride quality, surface drainage and winter operations. Roughness have wavelengths ranging from 500 mm up to some 40 m. The upper limit may be as high as 350 m when considering motion sickness aspects; motion sickness is generated by motion with down to 0.1 Hz frequency; in an ambulance car driving 35 m/s (126 km/h), waves with up to 350 m will excite motion sickness.
• Roundabout UK a road junction where typically three or more roads are joined by a circular section of road. Traffic 'on the roundabout' has priority over traffic on approach roads, unless indicated otherwise. In countrys where traffic drives on the left the roundabout is travelled in a clockwise direction. Also known as an island in parts of the UK.
• Shoulder - A clear, level area beside the driving lane(s). It helps support the roadway, helps drain the pavement, provides room for bicyclists and, in areas without sidewalks, pedestrians, allows disabled to get out of the road; a hard shoulder is paved, a soft shoulder is unpaved.
• State highway - Road numbered by the state, falling below numbered national highways (like U.S. Routes) in the hierarchy or a road maintained by the state, including nationally-numbered highways