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At-grade
At-grade may refer to: * At-grade intersection, a crossing between roads on the same level * Road junction *Level crossing, where a road or path crosses a railway on the same level * Diamond crossing, where two railway tracks cross * At-grade railway, at level with the general surface See also * Grade separation, the opposite of at-grade *Junction (rail) A junction, in the context of rail transport, is a place at which two or more rail routes converge or diverge. This implies a physical connection between the tracks of the two routes (assuming they are of the same gauge), provided by ''points'' ( ..., where rail routes meet or cross on the same level * Street running, where the train, tram or rapid transit run within the street {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
At-grade Intersection
An intersection or an at-grade junction is a junction where two or more roads converge, diverge, meet or cross at the same height, as opposed to an interchange, which uses bridges or tunnels to separate different roads. Major intersections are often delineated by gores and may be classified by road segments, traffic controls and lane design. Types Road segments One way to classify intersections is by the number of road segments (arms) that are involved. * A three-way intersection is a junction between three road segments (arms): a T junction when two arms form one road, or a Y junction, the latter also known as a fork if approached from the stem of the Y. * A four-way intersection, or crossroads, usually involves a crossing over of two streets or roads. In areas where there are blocks and in some other cases, the crossing streets or roads are perpendicular to each other. However, two roads may cross at a different angle. In a few cases, the junction of two road segments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Level Crossing
A level crossing is an intersection where a railway line crosses a road, path, or (in rare situations) airport runway, at the same level, as opposed to the railway line crossing over or under using an overpass or tunnel. The term also applies when a light rail line with separate right-of-way or reserved track crosses a road in the same fashion. Other names include railway level crossing, railway crossing (chiefly international), grade crossing or railroad crossing (chiefly American), road through railroad, criss-cross, train crossing, and RXR (abbreviated). There are more than 100,000 level crossings in Europe and more than 200,000 in North America. History The history of level crossings depends on the location, but often early level crossings had a flagman in a nearby booth who would, on the approach of a train, wave a red flag or lantern to stop all traffic and clear the tracks. Gated crossings became commonplace in many areas, as they protected the railwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
At-grade Railway
An intersection or an at-grade junction is a junction where two or more roads converge, diverge, meet or cross at the same height, as opposed to an interchange, which uses bridges or tunnels to separate different roads. Major intersections are often delineated by gores and may be classified by road segments, traffic controls and lane design. Types Road segments One way to classify intersections is by the number of road segments (arms) that are involved. * A three-way intersection is a junction between three road segments (arms): a T junction when two arms form one road, or a Y junction, the latter also known as a fork if approached from the stem of the Y. * A four-way intersection, or crossroads, usually involves a crossing over of two streets or roads. In areas where there are blocks and in some other cases, the crossing streets or roads are perpendicular to each other. However, two roads may cross at a different angle. In a few cases, the junction of two road segments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Road Junction
A junction is where two or more roads meet. History Roads began as a means of linking locations of interest: towns, forts and geographic features such as river fords. Where roads met outside of an existing settlement, these junctions often led to a new settlement. Scotch Corner is an example of such a location. In the United Kingdom and other countries, the practice of giving names to junctions emerged, to help travellers find their way. Junctions took the name of a prominent nearby business or a point of interest. As of the road networks increased in density and traffic flows followed suit, managing the flow of traffic across the junction became of increasing importance, to minimize delays and improve safety. The first innovation was to add traffic control devices, such as stop signs and traffic lights that regulated traffic flow. Next came lane controls that limited what each lane of traffic was allowed to do while crossing. Turns across oncoming traffic might be prohibited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Crossing
A double junction is a railway junction where a double-track railway splits into two double track lines. Usually, one line is the main line and carries traffic through the junction at normal speed, while the other track is a branch line that carries traffic through the junction at reduced speed. A number of configurations are possible. At grade Diamond The simplest and oldest arrangement consists of two turnouts (points) and a fixed Diamond crossing. Because the diamond needs to be relatively coarse, say 1 in 8, the curve radius is necessarily small, leading to a speed of perhaps . This type of junction is common on street-running tramways, where speeds are quite low and junction must fit into the available road space. Because the points are close together, the entire junction can be controlled by the mechanical point rodding of a single signal box. Signal passed at danger (SPAD) protection — A train from R to P with 12 points reverse is protected from a train f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grade Separation
In civil engineering (more specifically highway engineering), grade separation is a method of aligning a junction of two or more surface transport axes at different heights (grades) so that they will not disrupt the traffic flow on other transit routes when they cross each other. The composition of such transport axes does not have to be uniform; it can consist of a mixture of roads, footpaths, railways, canals, or airport runways. Bridges (or overpasses, also called flyovers), tunnels (or underpasses), or a combination of both can be built at a junction to achieve the needed grade separation. In North America, a grade-separated junction may be referred to as a ''grade separation'' or as an '' interchange'' – in contrast with an '' intersection'', ''at-grade'', a '' diamond crossing'' or a ''level crossing'', which are not grade-separated. Effects Advantages Roads with grade separation generally allow traffic to move freely, with fewer interruptions, and at higher ove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Junction (rail)
A junction, in the context of rail transport, is a place at which two or more rail routes converge or diverge. This implies a physical connection between the tracks of the two routes (assuming they are of the same gauge), provided by ''points'' (US: switches) and signalling. Junctions are important for rail systems, their installation into a rail system can expand route capacity, and have a powerful impact upon on-time performance. Overview In a simple case where two routes with one or two tracks each meet at a junction, a fairly simple layout of tracks suffices to allow trains to transfer from one route to the other. More complicated junctions are needed to permit trains to travel in either direction after joining the new route, for example by providing a triangular track layout. In this latter case, the three points of the triangle may be given different names, for example using points of the compass as well as the name of the overall place. Rail transport operations refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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