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A cat's eye or road stud is a retroreflective safety device used in road marking and was the first of a range of raised pavement markers.
| | This article needs additional citations for verification .(December 2023) |
A cat's eye or road stud is a retroreflective safety device used in road marking and was the first of a range of raised pavement markers.
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The cat's eye design originated in the UK in 1934 and is today used all over the world. [1] The original form consisted of two pairs of retroreflectors set into a white rubber dome, mounted in a cast iron housing. This is the kind that marks the centre of the road, with one pair of cat's eyes showing in each direction. A single-ended form has become widely used in other colours at road margins and as lane dividers. Cat's eyes are particularly valuable in fog and are largely resistant to damage from snow ploughs.
A key feature of the cat's eye is the flexible rubber dome which is occasionally deformed by the passage of traffic. A fixed rubber wiper cleans the surface of the reflectors as they sink below the surface of the road [2] (the base tends to hold water after a shower of rain, making this process even more efficient). The rubber dome is protected from impact damage by metal "kerbs" – which also give tactile and audible feedback for wandering drivers.
The inventor of cat's eyes was Percy Shaw of Boothtown, Halifax, West Yorkshire, England. When the tram-lines were removed in the nearby suburb of Ambler Thorn, he realised that he had been using the polished steel rails to navigate at night. [3] The name "cat's eye" comes from Shaw's inspiration for the device: the eyeshine reflecting from the eyes of a cat. In 1934, he patented his invention (patents Nos. 436,290 and 457,536), and on 15 March 1935, founded Reflecting Roadstuds Limited in Halifax to manufacture the items. [4] [2] The name Catseye is their trademark. [5] The retroreflecting lens had been invented six years earlier for use in advertising signs by Richard Hollins Murray, an accountant from Herefordshire [6] [7] and, as Shaw acknowledged, they had contributed to his idea. [3]
The blackouts of World War II (1939–1945) and the shuttered car headlights then in use demonstrated the value of Shaw's invention and helped popularise their mass use in the UK. After the war, they received firm backing from a Ministry of Transport committee led by James Callaghan and Sir Arthur Young. Eventually, their use spread all over the world.
In 2006, Cat's eyes were voted one of Britain's top 10 design icons in the Great British Design Quest organised by the BBC and the Design Museum, a list which included Concorde, Mini, Supermarine Spitfire, K2 telephone box, World Wide Web and the AEC Routemaster bus. [8] [9]
In the United Kingdom, different colours of cat's eyes are used to denote different situations:
These units are not very visible in daylight and are generally used in conjunction with traditionally painted lines. Temporary cat's eyes with just a reflective strip are often used during motorway repair work. These are typically day glow green/yellow so they are easily visible in daylight as well as in darkness; they can then be used on their own for lane division.
Also seen during motorway repair work are plastic traffic pillars that are inserted into the socket of a retractable cat's eye rather than being free-standing. These are often used in conjunction with two rows of the temporary cat's eyes to divide traffic moving in opposite directions during motorway roadworks.
Solar-powered cat's eyes known as solar road studs and showing a red or amber LED to traffic, have been introduced on roads regarded as particularly dangerous at locations throughout the world. [11] [12] However, shortly after one such installation in Essex in the autumn of 2006 the BBC reported that the devices, which flash at an almost imperceptibly fast rate of 100 times a second, could possibly set off epileptic fits and the Highways Agency had suspended the programme. [13] The suspension appeared to have been lifted by 2015, when LED cat's eyes began to be installed along newly re-paved sections of the A1 and A1(M) in County Durham and Tyne and Wear.
Flashing blue LED cat's eyes were demonstrated on the TV show Accident Black Spot, aired on Channel 4 on 19 December 2000, which alert the driver to potential ice on the road when a low enough temperature, provisionally set at 3 °C (37 °F), is reached. Proposed enhancements in 2013 were to change the standard white light to amber for four seconds after the passing of a vehicle, or red if the following vehicle is too close or traffic ahead is stationary. [14]
In Ireland yellow cat's eyes are used on all hard shoulders, including motorways (neither red nor blue cat's eyes are used). In addition, standalone reflector batons are often used on the verge of Irish roads. Green cat's eyes are used to alert motorists to upcoming junctions. There are limited installations of actively powered cats eyes, which flash white light, on particularly dangerous sections of road such as the single carriageway sections of the N11.
The closest equivalent in the United States is the Stimsonite retroreflective raised pavement marker. Stimsonite markers are made out of plastic, not metal, and were invented in 1963.
In New Zealand, roads are generally marked with white reflective cat's eyes every 10-metres along the centreline, occasionally on high volume roads; both Botts' dots and cat's eyes are used (typically there is one cat's eye followed by three Botts' dots places in every ten-metre stretch of highway). The colour pattern on New Zealand roads is white or yellow cat's eyes along the centre of the road (yellow indicating overtaking is not permitted), and in certain places red dots along the hard shoulder or left edge of a motorway. Single blue cat's eyes are used to indicate the location of fire hydrants. In rural settings and along State Highways, these markings are augmented by retroreflective posts along the edge of the road (white reflectors on the left, yellow reflectors on the right when on a left turning bend). Bridges are similarly marked with retro-reflective markings in diagonal bands of white and black (to the left) and yellow and black (to the right). [15]
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In almost all European countries, cat eye road studs will include reflective lenses of some kind. By contrast to the UK where use of cat's eyes is widespread, in Continental Europe, cat's eyes are rarely used as a permanent fixture. Most appear white or gray during daylight; the colors discussed here are the color of light they reflect. Because of their inconspicuousness during the day, they are always used in conjunction with painted retro-reflective lines; they are never seen on their own.
White markers — for lane markings. When used on dual carriageways, motorways, or one-way roads, they may illuminate red on the reverse, to indicate drivers are traveling the wrong way. Yellow or amber markers — These are found next to the central reservation (US: median) on motorways and dual carriageways and, in the Republic of Ireland, are also used on hard shoulders. Red markers — These are found by the hard shoulder on motorways and at the edge of the running surface on other roads. They are also occasionally used to indicate a no-entry road and when traveling down the wrong way of the motorway/dual carriageway. Green markers — These are used where slip-roads leave and join the main carriageway on dual carriageways. In some countries, they are also used across the entrances of minor roads or accesses onto major single carriageway roads or lay-bys. Blue markers — Are used to indicate the entrance to police reserved slip-roads (these do not lead anywhere, they are to allow police to park and monitor motorway traffic). The exception to the above rules are:
Fluorescent yellow markers — These are used to indicate temporary lanes during roadworks on major roads and are glued to the road surface; they are never embedded in it. Any painted markings will be removed from the road surface if they contradict the markers. They are fluorescent yellow in colour, so they stand out in the day, but reflect white light at night. Where used, they are much more numerous and dense than standards markers, as they are not used in conjunction with painted lines. They also appear yellow on the edges but reflect red on the left side or amber on the right
In Lebanon, cat's eyes are widely used on most freeways, highways and roadways. On freeways and highways, every one (or sometimes two) white stripes separating lanes is followed by a white shining cat's eye. On the edge of the road next to the median strip, a yellow cat's eye is placed every 10 metres (33 ft). On the road shoulders a red shining cat's eye is placed every 10 metres (33 ft). On roadways separated by double yellow lines, a yellow cat's eye is placed inside the double yellow lines every 10 metres (33 ft). Before speed bumps, a series of cat's eyes are placed shining white to the oncoming traffic and red to the car from the opposite direction. On pedestrian crossings, blue shining cat's eyes are placed after every zebra line. On roads with traffic lights, a series of red shining cat's eyes are placed 50 metres (160 ft) before traffic lights to make drivers slow down.[ citation needed ]
On the morning of 25 April 1999 on the M3 motorway in Hampshire, England, a van dislodged the steel body of a cat's eye which flew through the windscreen of a following car and hit electronic musician Kemistry, who was a passenger, in the face, killing her instantly. The coroner recorded a verdict of accidental death. [16] Investigators acknowledged that the cat's eye bodies occasionally came loose, but added that such an accident was previously unheard of. [17] A question was asked in the House of Lords about the safety of cat's eyes in light of the incident, and the Highways Agency conducted an investigation into the "long-term integrity and performance" of various types of road stud. [18]
In the biopic Ferrari (2003 film) a damaged metal road stud component is portrayed as causing a fatal accident in the 1957 Mille Miglia road race. At the village of Guidizzolo while travelling along a dead straight road at 150 mph (240 km/h) a worn left front tyre on the Ferrari 335 S driven by Alfonso de Portago is shown sliced open by a damaged cat's eye. The ensuing blowout causes de Portago's car to violently flip over and fly out of control, killing him, his navigator and nine onlookers, including children.
A corner reflector is a retroreflector consisting of three mutually perpendicular, intersecting flat reflective surfaces. It reflects waves incident from any direction directly towards the source, but translated. The three intersecting surfaces often are triangles or may have square shapes. Radar corner reflectors made of metal are used to reflect radio waves from radar sets. Optical corner reflectors, called corner cubes or cube corners, made of three-sided glass prisms, are used in surveying and laser ranging.
A retroreflector is a device or surface that reflects radiation back to its source with minimum scattering. This works at a wide range of angle of incidence, unlike a planar mirror, which does this only if the mirror is exactly perpendicular to the wave front, having a zero angle of incidence. Being directed, the retroflector's reflection is brighter than that of a diffuse reflector. Corner reflectors and cat's eye reflectors are the most used kinds.
A shoulder, hard shoulder or breakdown lane is an emergency stopping lane by the verge on the outer side of a road or motorway. Many wider freeways, or expressways elsewhere have shoulders on both sides of each directional carriageway—in the median, as well as at the outer edges of the road, for additional safety. Shoulders are not intended for use by through traffic, although there are exceptions.
Percy Shaw, was an English inventor and businessman. He patented the reflective road stud or "cat's eye" in 1934, and set up a company to manufacture his invention in 1935.
A dual carriageway (BrE) or a divided highway (AmE) is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation (BrE) or median (AmE). Roads with two or more carriageways which are designed to higher standards with controlled access are generally classed as motorways, freeways, etc., rather than dual carriageways.
Traffic cones, also called pylons, witches' hats, road cones, highway cones, safety cones, caution cones, channelizing devices, construction cones, roadworks cones, or just cones, are usually cone-shaped markers that are placed on roads or footpaths to temporarily redirect traffic in a safe manner. They are often used to create separation or merge lanes during road construction projects or automobile accidents, although heavier, more permanent markers or signs are used if the diversion is to stay in place for a long period of time.
Bicycle lighting is illumination attached to bicycles whose purpose above all is, along with reflectors, to improve the visibility of the bicycle and its rider to other road users under circumstances of poor ambient illumination. A secondary purpose is to illuminate reflective materials such as cat's eyes and traffic signs. A third purpose may be to illuminate the roadway so that the rider can see the way ahead. Serving the latter purposes require much more luminous flux and thus more power.
A raised pavement marker is a safety device used on roads. These devices are usually made with plastic, ceramic, thermoplastic paint, glass or occasionally metal, and come in a variety of shapes and colors. Raised reflective markers, such as plastic, ceramic, or metal ones, include a lens or sheeting that enhances their visibility by retroreflecting automotive headlights, while glass road studs gather automotive headlights with a dome shape and reflect the lights with a reflective layer within. Some other names for specific types of raised pavement markers include convex vibration lines, Botts' dots, delineators, cat's eyes, road studs, or road turtles. Sometimes they are simply referred to as "reflectors".
Road signs in the Republic of Ireland do not differ greatly from those used elsewhere in Europe – with the notable exception that hazard or warning signs follow the 'MUTCD' style of a yellow diamond shape. The symbols used on these warning signs do, nevertheless, resemble much more closely those used in the rest of Europe than many of those seen in the United States.
Road surface marking is any kind of device or material that is used on a road surface in order to convey official information; they are commonly placed with road marking machines. They can also be applied in other facilities used by vehicles to mark parking spaces or designate areas for other uses. In some countries and areas, road markings are conceived as horizontal traffic signs, as opposed to vertical traffic signs placed on posts.
Road signs in the United Kingdom and in its associated Crown dependencies and overseas territories conform broadly to European design norms, though a number of signs are unique: direction signs omit European route numbers, and road signs generally use the imperial system of units, unlike the rest of Europe. Signs in Wales (Welsh) and parts of Scotland are bilingual.
Botts' dots are round non-reflective ceramic raised pavement markers. In many parts of the US, Botts' dots are used, along with reflective raised pavement markers, to mark lanes on highways and arterial roads. They provide tactile and auditory feedback to drivers when moving across designated travel lanes, and are analogous to rumble strips.
Road signs in Sweden are regulated in Vägmärkesförordningen, VMF (2007:90), and are to be placed 2 metres from the road with the sign 1.6 m from the base for motorized roads. Except for route numbers, there are a maximum of three signs on a pole, with the most important sign at the top. All signs have a reflective layer added on selected parts of the sign as is custom in European countries; most larger signs also have their own illumination.
A single carriageway is a road with one, two or more lanes arranged within a one carriageway with no central reservation/median strip to separate opposing flows of traffic. A single-track road is a type of single carriageway with a single lane with passing places for traffic in both directions. An undivided highway is the term used for motorways with two or more lanes with no central reservation/median strip. Road traffic safety is generally worse for high-speed single carriageways than for dual carriageways due to the lack of separation between traffic moving in opposing directions.
The design of road signs in Poland is regulated by Regulation of the Ministers of Infrastructure and Interior Affairs and Administration on road signs and signals. The Annex 1 to the regulation describes conditions related to usage of the road signs – size, visibility, colors and light reflections, typeface and text, criteria of choosing the type of foil to signs faces, colorful specimens and schematics.
A highway location marker is the modern-day equivalent of a milestone. Unlike traditional milestones, however, which were originally carved from stone and sited at one-mile intervals, modern highway location markers are made from a variety of materials and are almost invariably spaced at intervals of a kilometre or a fraction thereof. In some countries they may be known as driver location signs, milestones or kilometre stones.
Reflecting Roadstuds is the main company in the UK that manufactures cat's eyes for use on roads.
Road traffic control devices are markers, signs and signal devices used to inform, guide and control traffic, including pedestrians, motor vehicle drivers and bicyclists. These devices are usually placed adjacent, over or along the highways, roads, traffic facilities and other public areas that require traffic control.
Terminology related to road transport—the transport of passengers or goods on paved routes between places—is diverse, with variation between dialects of English. There may also be regional differences within a single country, and some terms differ based on the side of the road traffic drives on. This glossary is an alphabetical listing of road transport terms.
Yellow lines are road markings used in various territories.
David Lydford, of Hampshire Police, said: Cat's eyes sometimes work loose, but I have never come across an accident like this in my 28 years with the police.