of the road which form a shoulder for the lower or upper layers of the road surface are not part of the roadway, nor are those parts of the road intended for the circulation of road vehicles which are not self-propelled or for the parking of vehicles. Cat's eye Reflective raised pavement marker used on roads Chicane Sequence of tight serpentine curves (usually an S-shape curve or a bus stop) Chipseal Road surface composed of a thin layer of crushed stone 'chips' and asphalt emulsion. It seals the surface and protects it from weather, but provides no structural strength. It is cheaper than asphalt concrete or concrete. In the United States, it is usually only used on low volume rural roads Corniche Road on the side of a cliff or mountain, with the ground rising on one side and falling away on the other Cross slope The slope of the pavement, expressed as units of rise per unit of run, or as a percentage Curb (kerb) A raised edge at the side of the roadway. Curb extension (also kerb extension, bulb-out, nib, elephant ear, curb bulge and blister) Traffic calming measure, intended to slow the speed of traffic and increase driver awareness, particularly in built-up and residential neighborhoods. Cycle lane Part of a carriageway designated for cycles and distinguished from the rest of the carriageway by longitudinal road markings. Mopeds may also be allowed to use a cycle lane. Cycle track Independent road or part of a road designated for cycles and sign-posted as such. A cycle track is separated from other roads or other parts of the same road by structural means. Mopeds may also be allowed to use the cycle track. Cycling infrastructure Cycling-friendly infrastructure integrated into the roadway or in its own right of way Drainage gradient Farm-to-market road A state road or county road that connects rural or agricultural areas to market towns. Fork (literally "fork in the road") Type of intersection where a road splits Grade Longitudinal slope Green lane (UK) Unsurfaced road, may be so infrequently used that vegetation colonises freely, hence 'green'. Many green lanes are ancient routes that have existed for millennia. Guide rail Prevents vehicles from veering off the road into oncoming traffic, crashing against solid objects or falling from a road. Also called a guard rail or traffic barrier. Gutter A drainage channel usually at the edge of the road