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Doria Mayberry
Traffic Control installs and maintains traffic signs and street name blades throughout the City. They are also responsible for all curb painting, pavement legends and striping. With over 53,000 street name blades and traffic signs the job is a tough one. We use the latest and most effective products to produce signs that will repel graffiti and resist fading. Currently, Traffic Control is in the process of replacing the old green street name blades with larger, more colorful blue and gold signs. The new signage is not only more attractive but easier to read as well.
States must adopt the 11th Edition National MUTCD or have a State MUTCD or Supplement that is in substantial conformance with the National MUTCD as their legal State standard for traffic control devices within two years. The Federal Register notice, which provides detailed discussion of the final dispositions of major changes from the 2009 Edition, can be viewed at -27178. To view the 11th Edition of the MUTCD and other related information, go to the MUTCD Current Edition web page.
The MUTCD, which has been administered by the FHWA since 1971, is a compilation of national standards for all traffic control devices, including road markings, highway signs, and traffic signals. It is updated periodically to accommodate the nation's changing transportation needs and address new safety technologies, traffic control tools, and traffic management techniques.
On December 19, 2023, a Final Rule adopting the 11th Edition of the MUTCD was published in the Federal Register with an effective date of January 18, 2024. States must adopt the 11th Edition of the National MUTCD as their legal State standard for traffic control devices within two years from the effective date. The Federal Register notice, which provides detailed discussion of the final dispositions of major changes from the 2009 edition, can be viewed at -27178.
Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled airspace. The primary purpose of ATC worldwide is to prevent collisions, organize and expedite the flow of air traffic, and provide information and other support for pilots.[1]
Air traffic controllers monitor the location of aircraft in their assigned airspace by radar and communicate with the pilots by radio.[2] To prevent collisions, ATC enforces traffic separation rules, which ensure each aircraft maintains a minimum amount of empty space around it at all times. It is also common for ATC to provide services to all private, military, and commercial aircraft operating within its airspace, not just civilian aircraft.[citation needed] Depending on the type of flight and the class of airspace, ATC may issue instructions that pilots are required to obey, or advisories (known as flight information in some countries) that pilots may, at their discretion, disregard. The pilot in command is the final authority for the safe operation of the aircraft and may, in an emergency, deviate from ATC instructions to the extent required to maintain safe operation of their aircraft.[3]
In 1920, Croydon Airport, London, was the first airport in the world to introduce air traffic control.[5] The "aerodrome control tower" was a wooden hut 15 ft (4.6 m) high with windows on all four sides. It was commissioned on February 25, 1920 and provided basic traffic, weather and location information to pilots.[6][7]
In the United States, air traffic control developed three divisions. The first of several air mail radio stations (AMRS) was created in 1922 after World War I when the U.S. Post Office began using techniques developed by the Army to direct and track the movements of reconnaissance aircraft. Over time, the AMRS morphed into flight service stations. Today's flight service stations do not issue control instructions, but provide pilots with many other flight related informational services. They do relay control instructions from ATC in areas where flight service is the only facility with radio or phone coverage. The first airport traffic control tower, regulating arrivals, departures and surface movement of aircraft at a specific airport, opened in Cleveland in 1930. Approach/departure control facilities were created after adoption of radar in the 1950s to monitor and control the busy airspace around larger airports. The first air route traffic control center (ARTCC), which directs the movement of aircraft between departure and destination, was opened in Newark in 1935, followed in 1936 by Chicago and Cleveland.[8] Currently in the U.S., the Federal Aviation Administration (FAA) operates 22 ARTCCs.
After the 1956 Grand Canyon mid-air collision, killing all 128 on board, the FAA was given the air-traffic responsibility over the United States in 1958, and this was followed by other countries.In 1960, Britain, France, Germany and the Benelux countries set up Eurocontrol, intending to merge their airspaces.The first and only attempt to pool controllers between countries is the Maastricht Upper Area Control Centre (MUAC), founded in 1972 by Eurocontrol and covering Belgium, Luxembourg, the Netherlands and north-western Germany. In 2001, the EU aimed to create a "Single European Sky", hoping to boost efficiency and gain economies of scale.[9]
The primary method of controlling the immediate airport environment is visual observation from the airport control tower. The tower is a tall, windowed structure located on the airport grounds. Air traffic controllers are responsible for the separation and efficient movement of aircraft and vehicles operating on the taxiways and runways of the airport itself, and aircraft in the air near the airport, generally 5 to 10 nautical miles (9 to 18 km) depending on the airport procedures. A controller must carry out the job using the precise and effective application of rules and procedures; however, they need flexible adjustments according to differing circumstances, often under time pressure.[10] In a study that compared stress in the general population and this kind of system markedly showed more stress level for controllers. This variation can be explained, at least in part, by the characteristics of the job.[11]
Surveillance displays are also available to controllers at larger airports to assist with controlling air traffic. Controllers may use a radar system called secondary surveillance radar for airborne traffic approaching and departing. These displays include a map of the area, the position of various aircraft, and data tags that include aircraft identification, speed, altitude, and other information described in local procedures. In adverse weather conditions, the tower controllers may also use surface movement radar (SMR), surface movement guidance and control system (SMGCS), or advanced surface movement guidance and control system (ASMGCS) to control traffic on the maneuvering area (taxiways and runway).
Remote and virtual tower (RVT) is a system based on air traffic controllers being located somewhere other than at the local airport tower and still able to provide air traffic control services.[12][13][14] Displays for the air traffic controllers may be live video, synthetic images based on surveillance sensor data, or both.
Ground control (sometimes known as ground movement control, GMC) is responsible for the airport movement areas,[15] as well as areas not released to the airlines or other users. This generally includes all taxiways, inactive runways, holding areas, and some transitional aprons or intersections where aircraft arrive, having vacated the runway or departure gate. Exact areas and control responsibilities are clearly defined in local documents and agreements at each airport. Any aircraft, vehicle, or person walking or working in these areas is required to have clearance from ground control. This is normally done via VHF/UHF radio, but there may be special cases where other procedures are used. Aircraft or vehicles without radios must respond to ATC instructions via aviation light signals or else be led by vehicles with radios. People working on the airport surface normally have a communications link through which they can communicate with ground control, commonly either by handheld radio or even cell phone. Ground control is vital to the smooth operation of the airport because this position impacts the sequencing of departure aircraft, affecting the safety and efficiency of the airport's operation.
Some busier airports have surface movement radar (SMR),[15] such as ASDE-3, AMASS, or ASDE-X, designed to display aircraft and vehicles on the ground. These are used by ground control as an additional tool to control ground traffic, particularly at night or in poor visibility. There is a wide range of capabilities on these systems as they are being modernized. Older systems will display a map of the airport and the target. Newer systems include the capability to display higher-quality mapping, radar targets, data blocks, and safety alerts, and to interface with other systems such as digital flight strips.
Air control (known to pilots as tower or tower control) is responsible for the active runway surfaces.[15] Air control clears aircraft for takeoff or landing, ensuring that prescribed runway separation will exist at all times. If the air controller detects any unsafe conditions, a landing aircraft may be instructed to "go-around" and be re-sequenced into the landing pattern. This re-sequencing will depend on the type of flight and may be handled by the air controller, approach, or terminal area controller.
Within the tower, a highly disciplined communications process between the air control and ground control is an absolute necessity. Air control must ensure that ground control is aware of any operations that will impact the taxiways, and work with the approach radar controllers to create gaps in the arrival traffic to allow taxiing traffic to cross runways and to allow departing aircraft to take off. Ground control needs to keep the air controllers aware of the traffic flow towards their runways to maximise runway utilisation through effective approach spacing. Crew resource management (CRM) procedures are often used to ensure this communication process is efficient and clear. Within ATC, it is usually known as TRM (team resource management) and the level of focus on TRM varies within different ATC organisations.
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