Highway location marker
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.
Route identification
Until the beginning of the twentieth century, highways were usually named rather than numbered.In most cases they had the name of the town or city to which they headed, for example The Old Portsmouth Road. Other ancient highway names include The Pilgrims Way, Watling Street and the Via Appia.
However, with the increase in private traffic after the First World War a simpler way of identifying roads was needed. Different countries adopted different ways of identifying roads. Under the 1966 Local Government Act Great Britain adopted a system of road numbering so that each roads had a unique number across the entire country. The relative importance of the road was identified by a "A" or a "B" prefix.
In France roads that were in the care of the national government were prefixed by "RN" and had a number that was unique across all of France. Roads that were maintained by departments had a number that was prefixed by "D" and were unique within the department concerned while roads that were maintained by communes had numbers that were prefixed by a "C" were unique within a commune. The advent of motorways meant an extension to both the British and the French methods of roads identification.
Highway location markers often have the route identifier marked on them.
Location identification
Location identification is achieved by the highway location markers having numbers on them – usually the distance from some reference point.A highway may be divided into more than one sector, with different sectors having different numbering sequences. Sector boundaries could be the boundaries of a state, or could be the middle of a large town or any one of a number of other locations.
Each one of numbering sequence is defined by its reference point and all the numbers within one sequence having a fixed relationship to the reference point and hence to each other. The reference point might be the start of the highway, it might be the start of the sector or it might be some artificial point that is located before the start of the highway. Such artificial points include the Zero Milestone in Washington, D.C., and Charing Cross in London.
In some countries such as Spain or the United States, highway exit numbers are identified using location identifiers.
Rerouting problems
If a highway is rerouted, then invariably its length changes. This can be handled in one of three ways:- Location identifiers can be adjusted to take the rerouting into account. This is often impractical.
- The new section of road can be given a new identifier. This is often done in Italy.
- The sequence can be broken. Any adjustments in the sequence are recorded using the milepost equation.
Carriageway identification
Examples worldwide
These location marker examples have been chosen because each has a novel feature over and above route and location identification.India
The Indian location markers carry a number of different distances. The marker illustrated carries the following information:Although the sign illustrated uses Latin script, a number of Indian location markers use the Indian official language Hindi or the predominant language of the state in which they are located.
Ireland
Location reference indicator signs are provided on motorways and dual carriageway national roads. They indicate the route number of the route being travelled on, the direction of travel and the distance from the start point of the route. LRI signs are placed every 500 metres.LRI signs are supplemented with location reference markings, which are road markings painted in the hard shoulder parallel to the road. They contain the same information as LRIs, though the letter from the route number is omitted. They are placed every 100 metres and also indicate the direction to the nearest emergency telephone.
Italy
The highway location markers in Italy are part of the category of distance signs, subcategory of indication signs, and are of two types, those that indicate the distance in kilometers and those that indicate the distance in hectometers. In Italy, until before 1959, the function of mileage signals was performed by milestones. In the Consolidated Law Regulation of 1959, figure 103b mentions the use of the motorway confirmation sign, consisting of a white box on the left with the distance from the point of origin of the road and a blue rectangle with white characters in which the name of the next exit is shown with the relative distance in kilometers. In the circular of the Ministry of Public Works n. 9540/1969 "Motorway signs", signs with a similar function have been adopted to be installed on the traffic island.In Italy the highway location marker is a square white sign with the current kilometer of the road written on it. This sign is accompanied by the sign that identifies the road if it indicates the kilometers of a state, regional, provincial or extra-urban municipal road. If the sign indicates kilometers of a motorway the sign is accompanied by a green sign indicating the next exit with the distance remaining if the kilometer ends in 1, 3, 4, 6, 7 or 9, the next service area with the remaining distance if the kilometer ends with 2, 5 and 8 or the highway with the remaining distance if the kilometer ends with 0.
To mark the distance from the starting point of a road, progressive hectometric signs are also used. These signs are placed every and carry a two-line indication, such as. The sign indicates in the lower part the kilometer of the last kilometer progressivity sign or of the next one and indicates in the upper part the hectometers in Roman numerals the distance to the last sign or the remaining distance to the next sign. These signs are positioned on all types of extra-urban roads whose length is such as to make their use appropriate.
Malaysia
Malaysia has its own unique set of location markers in kilometre and hectometre. They include the route code, location number from the road starting point and sometimes direction of the carriageway. Green background are for toll expressways and blue backgrounds are for non-tolled highways.On the other hand, federal roads have marker which are placed every kilometre and includes the distance to primary destination and location number. Every five kilometres however the marker includes the route code, distance to primary destination, distance to secondary destination and location number.
Myanmar
In Myanmar, furlongs have been used at least until 2010 in conjunction with miles to indicate distances on highway signs, for example on the Yangon-Mandalay Expressway.Netherlands
As the name suggests, Dutch hectometre markers are spaced at 100-metre intervals. In addition to showing the motorway number and location, they also bear a carriageway identifier – Li for links and Re for rechts. The carriageways are identified as being left-hand and right-hand as viewed by somebody looking in the direction of increasing location numbers. By and large, Dutch location numbers increase as one moves away from Amsterdam, or in the case of roads that do not originate in Amsterdam, location numbers increase as one moves eastwards away from the North Sea. Carriageway identifiers 'a', 'b', 'c' and 'd' are used to identify slip roads on and off the motorway.Another novel concept on Dutch hectometre markers is that speed limits are displayed on the marker boards when the speed limit is less than the national default of 120 km/h.
United Kingdom
In the UK, driver location signs are placed every along each side of motorways, and along some other major roads. They were first introduced in 2003, and they complement distance marker posts, small roadside posts at intervals, used for road maintenance and administrative purposes. Both types of sign display a unique location number. The number is given without units but is the distance in kilometres from a designated datum location for the road.Major British dual-carriageway roads have marker posts at 100-metre intervals. These posts, which are used for administrative purposes, give the distance in kilometres from some reference point. The digits on the posts are not designed to be used by the general public. There are no fixed rules for determining the reference points: they may be the centre of a city, an administrative boundary or follow some other rule. Marker posts on motorways also have arrows that point to the closest emergency telephone.
The advent of the mobile phone required a government rethink regarding marker posts. This has led to the erection of driver location signs in England
at about 500 metre intervals on many motorways.
Driver location signs have three pieces of information:
- The road identifier
- The carriageway identifier
- The location
The letter "A" normally denotes the carriageway in the direction of increasing location numbers, "B" the carriageway in the direction of decreasing location numbers while "J", "K", "L" and "M" denote junction slip roads.