cyclists and pedestrians no conflicts or a head start over traffic. The design makes a right turn on red, and sometimes left on red depending on the geometry of the intersection in question, possible in many cases, often without stopping. Protected Bicycle Path Cyclists ideally have a protected bike lane on separated by a concrete median with splay kerbs if possible, and have a protected bike lane width of at least 2 metres if possible (one way). Public space Place where anyone has a right to come without being excluded because of economic or social conditions Ranch road U.S. road that connects rural and agricultural areas to market towns Road number Often assigned to identify a stretch of public roads – often dependent on the type of road, with numbers differentiating between interstates, motorways, arterial thoroughfares, etc. Road-traffic safety Process to reduce the harm (deaths, injuries, and property damage) that result from vehicle crashes on public roads Roadworks Part or all of the road is occupied for work or maintenance 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 , waves with up to 350 m will excite motion sickness. Roundabout 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 countries where traffic drives on the left the roundabout is traveled in a clockwise direction. Also known as an island in parts of the UK. Segregated Bicycle Path Cyclists ideally have a protected bike lane separated by a concrete median with splay kerbs if possible, and have a protected bike lane width of at least 2 meters if possible (one way). Shoulder (also hard shoulder) A clear, level area to the side of the roadway available for stopping if needed. 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 Traffic Pedestrians, ridden or herded animals, vehicles, bicycles, and other conveyances