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, or allowed only when oncoming and crossing traffic was stopped.

This was followed by specialized junction designs that incorporated information about traffic volumes, speeds, driver intent and many other factors.

Types

The most basic distinction among junction types is whether or not the roads cross at the same or different elevations. More expensive, grade-separated interchanges generally offer higher throughput at higher cost. Single-grade intersections are lower cost and lower throughput. Each main type comes in many variants.[1]

Interchange

At interchanges, roads pass above or below each other, using grade separation and slip roads. The terms motorway junction and highway junction typically refer to this layout. They can be further subdivided into those with and without signal controls.

Signalized (traffic-light controlled) interchanges include such "diamond" designs as the diverging diamond,[2] Michigan urban diamond, three-level diamond, and tight diamond. Others include center-turn overpass, contraflow left, single loop, and single-point urban overpass.[3]

Non-signalized designs include the cloverleaf, contraflow left, dogbone (restricted dumbbell), double crossover merging,[2][4][5] dumbbell (grade-separated bowtie), echelon, free-flow interchange, partial cloverleaf, raindrop, single and double roundabouts (grade-separated roundabout), single-point urban, stack, and windmill.[3]

Autobahnkreuz (literally autobahn cross), short form kreuz, and abbreviated as AK, is a four-way interchange on the German autobahn network. Autobahndreieck (literally autobahn triangle), short form dreieck, and abbreviated as AD, is a three-way interchange on the German autobahn network.

Intersection

At intersections, roads cross at-grade. They also can be further subdivided into those with and without signal controls.

Signalized designs include advanced stop line, bowtie, box junction, continuous-flow intersection,[6] continuous Green-T, double-wide, hook turn, jughandle, median u-turn, Michigan left, paired, quadrant, seagulls, slip lane, split, staggered, superstreet, Texas T, Texas U-turn and turnarounds.[3]

Non-signalized designs include unsignalized variations on continuous-flow 3 and 4-leg, median u-turn and superstreet, along with Maryland T/J, roundabout and traffic circle.[3]

Safety

In the EU it is estimated that around 5,000 out of 26,100 people are killed in a junction collision, in 2015, while it was around 8,000 in 2006.[7] During the 2006–2015 decade, this means around 20% of road fatalities occur at junctions.[7]

By kind of users junctions fatalities are car users, 34%; pedestrians, 23%; motorcycle, 21%; pedal-cycle 12%; and other road users, the remaining.[7]

Cause of fatalities

It has been considered that several causes might lead to fatalities; for instance:[7]

  • Observation missed is frequent and can be classified in two classes:
    • physical ‘obstruction to view such as cars parked at a junction
    • human factors such as a red light missed due to distraction or inattention
  • faulty diagnosis incorrect or incomplete understanding.

Pedestrians

Intersections generally must manage pedestrian as well as vehicle traffic. Pedestrian aids include crosswalks, pedestrian-directed traffic signals ("walk light") and over/underpasses. Walk lights may be accompanied by audio signals to aid the visually impaired. Medians can offer pedestrian islands, allowing pedestrians to divide their crossings into a separate segment for each traffic direction, possibly with a separate signal for each.

Protected intersections for bicycles

Protected intersection design based on a common Dutch model, preserving the physical segregation of the cycle lane throughout the intersection

A number of features make this protected intersection much safer. A corner refuge island, a setback crossing of the pedestrians and cyclists, generally between 1.5–7 metres of setback, a forward stop bar, which allows cyclists to stop for a traffic light well ahead of motor traffic who must stop behind the crosswalk. Separate signal staging or at least an advance green for cyclists and pedestrians is used to give cyclists and pedestrians no conflicts or a head start over traffic. The design makes a right turn on red, and sometimes left on red depending on the geometry of the intersection in question, possible in many cases, often without stopping.[8]

Cyclists ideally have a protected bike lane on the approach to the intersection, separated by a concrete median with splay kerbs if possible, and have a protected bike lane width of at least 2 metres if possible (one way). In the Netherlands, most one way cycle paths are at least 2.5 metres wide.[9]

Bicycle traffic can be accommodated with the low grade bike lanes in the roadway or higher grade and much safer protected bicycle paths that are physically separated from the roadway.

See also

References

  1. ^ Hughes, Warren; Jagannathan, Ram; Sengupta, Dibu & Hummer, Joe (April 2010). Alternative Intersections/Interchanges: Informational Report (AIIR) (Report). Federal Highway Administration.
  2. ^ a b Hughes, Warren; Jagannathan, Ram (October 2009). "Double Crossover Diamond Interchange". Federal Highway Administration. FHWA-HRT-09-054. Retrieved April 22, 2012.
  3. ^ a b c d "Applied Technology and Traffic Analysis Program". University of Maryland. Archived from the original on 2014-05-03. Retrieved 2014-04-12.
  4. ^ "Double Crossover Merging Interchange".
  5. ^ Gingrich, Michael A., Sr. (June 2011). "DCMI (Double Crossover Merging Interchange)" (PDF). Institute of Transportation Engineers. Retrieved January 23, 2013.
  6. ^ Hummer, Joseph E. and Jonathan D. Reid. "Unconventional Left-Turn Alternatives for Urban and Suburban Arterials" (PDF). Transportation Research Board. Archived from the original (PDF) on 30 September 2007. Retrieved 13 June 2007.
  7. ^ a b c d European Road Safety Observatory (June 2017). Traffic Safety Basic Facts 2017: Junctions (PDF). European Road Safety Observatory.
  8. ^ http://www.protectedintersection.com/wp-content/uploads/2014/02/Falbo_ProtectedIntersection_Transcript1.pdf
  9. ^ "How wide is a Dutch cycle path?". 2011-06-29.
Bowtie (road)

The bowtie is a type of road intersection which replaces left turns (in jurisdictions that drive on the right) or right turns (in jurisdictions that drive on the left), with roundabouts on the cross street. It is an alternative to the Michigan left intersection.

Diamond interchange

A diamond interchange is a common type of road junction, used where a freeway crosses a minor road.

Hook turn

A hook turn (also known as a perimeter-style turn in Canada) is a road cycling maneuver and traffic-control mechanism in which vehicles that would normally turn from the closest lane of an intersection instead turn from the farthest lane, across all other lanes of traffic.

Hook turns are commonly used by cyclists as a safer alternative to merging with motor vehicles, or having to cross multiple lanes of traffic to reach a turning lane.

The legal use of hook turns by motor vehicles is relatively rare, but has been implemented in some jurisdictions (notably Melbourne, Australia) to keep the center of a road free from congestion for use by trams or other services.

Interchange (road)

In the field of road transport, an interchange is a road junction that uses grade separation, and typically one or more ramps, to permit traffic on at least one highway to pass through the junction without interruption from other crossing traffic streams. It differs from a standard intersection, where roads cross at grade. Interchanges are almost always used when at least one road is a controlled-access highway (freeway or motorway) or a limited-access divided highway (expressway), though they are sometimes used at junctions between surface streets.

Intersection (road)

This article primarily reflects practice in jurisdictions where vehicles are driven on the right. If not otherwise specified, "right" and "left" can be reversed to reflect jurisdictions where vehicles are driven on the left.

An intersection is an at-grade junction where two or more roads or streets meet or cross. Intersections may be classified by number of road segments, traffic controls, and/or lane design.

Kapilas Road Junction railway station

Kapilas Road Junction railway station is a railway station on the East Coast Railway network in the state of Odisha, India. It serves Kapilas Road. Its code is KIS. It has five platforms. Passenger, MEMU, Express trains halt at Kapilas Road Junction railway station.

Katihar–Siliguri line

The Katihar–Siliguri line is a railway line connecting Katihar in the Indian state of Bihar with Siliguri Junction in West Bengal, via Aluabari Road Junction (Islampur), Thakurganj and Bagdogra. It was a metre gauge track that was converted to 1,676 mm (5 ft 6 in) Broad Gauge in 2011.

Another railway line with a slightly different route with shorter distance exists between Siliguri Junction and Aluabari Road Junction (Islampur) and its details are available in Howrah–New Jalpaiguri line article.

Khurda Road Junction railway station

Khurda Road is an important railway junction station in the Indian state of Odisha. It serves Jatani, which is also known as Khurda Road.

Lanjigarh Road Junction railway station

Lanjigarh Road Junction railway station is a railway station on the East Coast Railway network in the state of Odisha, India. It serves Lanjigarh town. Its code is LJR. It has two platforms. Passenger, Express trains halt at Lanjigarh Road Junction railway station.

Merta Road Junction railway station

Merta Road Junction ( station code MTD ) also known as Merta Road Station which serves Merta City, India. Approximately 75-100 passenger trains pass through the station each day requiring its 3 platforms and serving more than 8000-10000 passengers per day. The station located around 105 km away from Jodhpur at Jodhpur - Bikaner route. This is a major railway station in Nagaur district, Rajasthan. The platform is semi well sheltered. Almost all facilities are available including water, sanitation.

Prachi Road Junction railway station

Prachi Road Junction railway station is a railway station on the Western Railway network in the state of Gujarat, India. Prachi Road Junction railway station is 45 km away from Veraval Junction railway station. Passenger trains halt here.

Protected intersection

A protected intersection is an at-grade road junction in which cyclists and pedestrians are separated from cars. Vehicles turning right (in countries driving on the right, or left in countries driving on the left) are separated by a car length from crossing cyclists and pedestrians, providing increased reaction times and visibility. Drivers looking to turn right have better visibility to cyclists and pedestrians as they can look to the side for conflicts instead of over their shoulders.

This type of intersection is common in the bike-friendly Netherlands. A few other countries and jurisdictions are beginning to install protected intersections similar to those in the Netherlands , including U.S. cities Salt Lake City, Austin, Davis and Boston, and Canadian cities Ottawa, Vancouver, and Waterloo.

Road Junction Windmill, Arizona

Road Junction Windmill is a populated place situated in Maricopa County, Arizona. It has an estimated elevation of 3,150 feet (960 m) above sea level.

Samuktala Road Junction railway station

Samuktala Road Junction is a railway junction station in Alipurduar district in the Indian state of West Bengal.

Seven Dials, Brighton

Seven Dials is a district surrounding a major road junction of the same name in Brighton, in the city of Brighton and Hove. It is located on high ground just northwest of Brighton railway station, south of the Prestonville area, and approximately ¾ mile north of the seafront.

The name refers to the seven roads which radiate outwards from the roundabout-controlled junction, and is derived from a seven-way junction in London featuring a monument with six sundials. The roundabout itself is notable as an early example of this type of road junction in the UK.Clockwise from the north, these are:

Prestonville Road

Chatham Place, leading to New England Road and Preston Circus - another major road junction

Buckingham Place, leading to the railway station by way of a sharply curving downhill slope

Dyke Road, one of the city's main roads - leading to the city centre

Vernon Terrace, leading to Montpelier Road and the seafront

Goldsmid Road, leading into Hove

The northward continuation of Dyke Road, leading eventually to the Devil's Dyke beauty spot on the South Downs

Singapur Road Junction railway station

Singapur Road Jn. is a junction station near Rayagada in Odisha where Koraput-Rayagada railway line meets Vizianagaram-Raipur mainline.

Spa Road Junction rail crash

The Spa Road Junction rail crash was an accident on the British railway system which occurred during the peak evening rush hour of 8 January 1999 at Spa Road Junction in Bermondsey, southeast London.

Three-way junction

A 3-way junction (or 3-way intersection) is a type of road intersection with three arms. A Y junction (or Y intersection) generally has 3 arms of equal size. A T junction (or T intersection) also has 3 arms, but one of the arms is generally a minor road connecting to a larger road.

Vasai Road railway station

Vasai Road Junction (formerly Bassein Road Junction, station Code: BS) is a railway station on the Western line and Vasai Road - Roha line of the Mumbai Suburban Railway network.

Vasai is a historical suburban town north of Mumbai and it is located in Palghar district. It is a much modern part of Vasai Taluka. It is a part of the new Vasai-Virar city.

It is a major railway station which bypasses Mumbai and connects the trains coming from Vadodara to Konkan Railway and Pune Junction railway station and further towards cities of Bengaluru and Hyderabad

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