Mechanical markers Road surface marking

the cat s eye, showing iron base, rubber housing , lenses

mechanical devices may raised or recessed road surface, , either reflective or non-reflective. permanent; movable.

cat s eye, invented percy shaw in 1930s, cat s eyes equip many major routes in british isles. consist of 4 reflective lenses mounted in durable white rubber housing, 2 facing fore , 2 facing aft. housing mounted within cast iron shoe, rubber housing sinks in when driven over. provides protection snow ploughing , allows lenses self-cleaning—they pass rubber blade when depressed. lenses available in variety of different colours, white, yellow/orange, green, red, , blue.
botts dots (low rounded white dots), named california caltrans engineer elbert botts, invented epoxy keeps them glued down, 1 type of mechanical non-reflective raised marker. used mark edges of traffic lanes, in conjunction raised reflective markers. botts dots used across travel lane draw drivers attention road. used in way alert drivers toll booths, school zones or other significant reduction of speed limit. used in warm climates since snow plows remove them along snow.


raised-profile marking machine



rumble strips commonly used same purpose. rumble strip can series of simple troughs (typically 1 cm deep , 10 cm wide) ground out of asphalt. other alternatives, similar botts dots, use raised strips, painted or glued surface. specific form of raised strips using thermoplastic called profile thermoplastic markings. markings created fusing thermoplastic pavement , create alternating elevation , recession pattern. can done inverted-profile markings or raised-profile markings. inverted-profile markings created pressing cog rolling on markings while wet make them corrugated. raised-profile markings created extruding thickness of thermoplastic @ specific interval create bumps. raised-profile markings sometime known convex traffic lines. uses of rumble strips can across travel direction (to warn of hazards ahead) or along travel direction (to warn of hazards of not staying within specific lane). main way of function creating strong vibration when driven on alert driver various upcoming hazards both sound , physical vibration of vehicle. in areas in united states, these rumble strips located along side of county, state, , inter state highways. oriented driver wandering off lane of traffic come in contact these strips , forewarned leave roadway. idea first started in atlanta, measure truck drivers on bypass after number of accidents in late 1980s involved drivers became distracted or fell asleep , left road.


white raised pavement marker near pea-structure side-line on highway surface



reflective markers used travel lane dividers, mark central reservation (median) or mark exit slip-roads. incorporating raised retro-reflective element, typically more visible @ night , in inclement weather standard road marking lines. color of markers varies depending on country of use; freeways in united states use reflectors manufactured appear white drivers proceeding in proper direction of travel, , appear red on reverse warn drivers proceeding against proper direction of travel, creating danger of head-on collision. reflective markers referred raised pavement markers, road studs, , (generically) in uk , ireland cat s eye, although name refers 1 particular brand of product. these markers can used other purposes such marking locations of fire hydrants (blue) or @ gates of gated communities indicate emergency service vehicles have code or device allows them open gate. in united kingdom , elsewhere, raised markers used mark crosswalks (crossings) assist blind in crossing streets. in colder climates, reflective markers may installed below ground using elongated narrow triangle, cut road surface allows device installed below road surface. newer technology allows these placed above ground snowplough-able rails attempt protect reflective components snowplough blade.

confusion marks left roadwork

typical dash marks in middle of lane after dowel bar retrofit roadwork

sometimes result of roadwork may leave visible marks on pavements. example dowel bar retrofit process reinforce concrete slabs in order extend life of older concrete pavements. completion of process leaves symmetrical pattern of dash marks on roadway, if there associated meaning pattern. when there many of them along roadway, motorists may interpret marks unknown form of mechanical markers or strange road surface markings. when roads under construction , lanes shifted laterally, marks may interfere temporary lane markings. marks dowel bar retrofit not intended form of road surface markings, responsible agencies try make these marks less visible motorists.