View source for Estimated time of arrival

{{Short description|Time when something is expected to arrive at a certain place}}

The '''estimated time of arrival''' ('''ETA''') is the time when a [[ship]], [[vehicle]], [[aircraft]], [[cargo]], [[person]], or [[emergency service]] is expected to arrive at a certain place.<ref>{{cite book |title=A Dictionary of Aviation |first=David W. |last=Wragg |isbn=9780850451634 |edition=first |publisher=Osprey |year=1973 |page=121}}</ref><ref>{{cite book |author1=Cameron, M. |author2=Brown, A. |chapter=Intelligent transportation system Mayday becomes a reality |title=Aerospace and Electronics (NAECON 1995) |date=May 1995 |volume=1 |pages=340–347 |publisher=[[IEEE]]}}</ref><ref>{{cite journal |author1=Propp, Douglas A. |author2=Rosenberg, Craig A. |title=A comparison of prehospital expected time of arrival and actual time of arrival to an emergency department |journal=[[The American Journal of Emergency Medicine]] |date=July 1991 |volume=9 |issue=4 |pages=301–303 |doi=10.1016/0735-6757(91)90045-L|pmid=2053997 }}</ref>

==Overview==
One of the more common uses of the phrase is in [[public transportation]] where the movements of [[train]]s, [[bus]]es, [[airplane]]s and the like can be used to generate estimated times of arrival depending on either a static timetable or through measurements on [[traffic]] intensity.{{citation needed|date=July 2012}} In this respect, the phrase or its abbreviation is often paired with its complement, '''estimated time of departure'''<!--boldface per WP:R#PLA--> ('''ETD'''), to indicate the expected start time of a particular journey. This information is often conveyed to a [[passenger information system]] as part of the core functionality of [[intelligent transportation system]]s.

For example, a certain flight may have a calculated ETA based on the [[speed]] by which it has covered the [[distance]] traveled so far. The remaining distance is divided by the speed previously measured to roughly estimate the arrival time.{{citation needed|date=July 2012}} This particular method does not take into account any unexpected events (such as new wind directions) which may occur on the way to the flight's destination.{{citation needed|date=November 2014}}

ETA is also used [[metaphor|metaphorically]] in situations where nothing actually moves physically, as in describing the time estimated for a certain task to complete (e.g. work undertaken by an individual; a computation undertaken by a [[computer program]]; or a process undertaken by an organization). The associated term is "estimated time of accomplishment", which may be a [[backronym]].{{citation needed|date=July 2012}}

==Applications==
Accurate and timely estimations of times of arrival are important in several application areas:
*In [[air traffic control]] arrival sequencing and scheduling, where scheduling aircraft arrival according to the first-come-first-served order of ETA at the runway minimizes delays.<ref>{{cite journal |title=Fast-time study of airline-influenced arrival sequencing and scheduling |author1=Carr, Gregory C. |author2=Erzberger, Heinz |author3=Neuman, Frank |journal=Journal of Guidance, Control, and Dynamics |volume=23 |number=3 |pages=526–531 |date=June 2000|doi=10.2514/2.4559 |bibcode=2000JGCD...23..526C }}</ref><ref>{{cite book |title=AIAA Guidance, Navigation, and Control 2006 |url=https://www.aiaa.org/ProceedingsDetail.aspx?id=3844 |chapter=Target tracking and Estimated Time of Arrival (ETA) Prediction for Arrival Aircraft |author1=Roy, Kaushik |author2=Levy, Benjamin |author3=Tomlin, Claire J. |publisher=[[AIAA]] |id=AIAA2006-6324 |date=August 2006}}</ref>
*In [[airport gate]] assignment methods, to optimize gate utilization.<ref>{{cite journal |title=Airport Gate Scheduling with Time Windows |author1=Lim, A. |author2=Rodrigues, B. |author3=Zhu, Y. |journal=Artificial Intelligence Review |volume=24 |number=1 |year=2005 |pages=5–31 |doi=10.1007/s10462-004-7190-4|s2cid=19496597 }}</ref>
*In [[elevator]] control, to minimize the average waiting time or journey time of passengers<ref>{{cite book |author1=Xiong, Bo |author2=Luh, Peter B. |author3=Chang, Shi Chung |chapter=Group Elevator Scheduling with Advanced Traffic Information for Normal Operations and Coordinated Emergency Evacuation |title=Robotics and Automation (ICRA 2005) |date=April 2005 |publisher=[[IEEE]] |pages=1419–1424}}</ref><ref>{{cite book |title=Estimated Time of Arrival (ETA) Based Elevator Group Control Algorithm with More Accurate Estimation |author1=Rong, Aiying |author2=Hakonen, Henri |author3=Lahdelma, Risto |date=December 2003 |url=http://tucs.fi/publications/view/?id=tRoHaLa03b |access-date=July 11, 2012 |publisher=Turku Centre for Computer Scienceo |isbn=952-12-1289-6}}</ref> ([[destination dispatch]]).

==References==
{{Wiktionary|ETA}}
{{Reflist}}

{{DEFAULTSORT:Estimated Time Of Arrival}}
[[Category:Time]]
[[Category:Airline tickets]]
[[Category:Passenger rail transport]]