Disputed Statements

Appian Way, Infrastructure

Standing Scholarly debate

Concerns Completion Year

Currently States -264

The Appian Way was built in stages over nearly five decades, not completed on one date. Appius Claudius Caecus began and completed the first section, from Rome to Capua, as a military road in 312 BC; the Romans then extended it stage by stage until it reached the port of Brundisium in 264 BC, the year recorded here as the completion of the road to its historic terminus.

Source Wikipedia: Appian Way tier 2

Autobahn, Infrastructure

Standing Scholarly debate

Concerns Completion Year

Currently States 1932

The Autobahn network has no single completion date; it grew over decades rather than opening all at once. The first public limited-access road of this kind, later designated Bundesautobahn 555, was completed between Cologne and Bonn in 1932. A separate stretch from Frankfurt am Main to Darmstadt, opened in 1935, is sometimes credited instead as the first true Autobahn because it more closely matched the later standard design.

Source Wikipedia: Autobahn tier 2

Bailey Yard, Infrastructure

Standing Scholarly debate

Concerns Completion Year

Currently States 1980

Bailey Yard was built and rebuilt in stages rather than completed on one date: a flat-switched yard from 1867, a 42-track hump yard added in 1948, a second 64-track hump yard added in 1968, and a replacement 50-track hump yard completed in 1980, the last major reconstruction described in the source consulted.

Source Wikipedia: Bailey Yard tier 2

Camel Transport, Modes

Standing Scholarly debate

Concerns Origin Year

Currently States -2500

The exact millennium is disputed among historians; the cited source places dromedary domestication in the 3rd millennium BC and Bactrian domestication around 2500 BC, so 2500 BC is recorded here as a representative point in a range the source itself calls unsettled.

Source Wikipedia: Camel tier 2

Electric Scooter Transport, Modes

Standing Scholarly debate

Concerns Origin Year

Currently States 2001

Wikipedia's History timeline names Go-Ped's May 2001 Hoverboard as the first full-suspension stand-up e-scooter; it does not state a confirmed date for the first electric stand-up scooter of any kind, since the 1986 Go-Ped stand-up scooters are described only as the first modern stand-up scooters without confirming electric propulsion, and the 1915 Autoped predecessor was gasoline powered, not electric.

Source Wikipedia: Electric Kick Scooter tier 2

Horseback Riding, Modes

Standing Scholarly debate

Concerns Origin Year

Currently States -3500

Wikipedia states there is controversy over the exact date horses were domesticated and first ridden, giving an estimate of approximately 3500 BC used here as a debated value.

Source Wikipedia: Equestrianism tier 2

Maritime Transport, Modes

Standing Scholarly debate

Concerns Origin Year

Currently States -65000

Expressed here as years before present rather than a calendar year. The first open ocean crossings, required to reach Sahul (Australia and New Guinea) from Sunda across Wallacea, are estimated at a minimum of 65,000 years before present, though the precise date and route are debated among archaeologists and no watercraft from this period survive; the date is inferred from the timing of human arrival in Sahul.

Source Sahul (Wikipedia) tier 2

Micromobility, Modes

Standing Scholarly debate

Concerns Origin Year

Currently States 2017

The term is usually credited to Horace Dediu, said to have coined it in 2017, but internet references to the term already existed by 2010, so the exact date of coinage is not firmly settled.

Source Wikipedia: Micromobility tier 2

Nord Stream, Infrastructure

Standing Scholarly debate

Concerns Completion Year

Currently States 2011

Nord Stream comprises two separate pipeline projects rather than one completion date: Nord Stream 1 entered service in 2011, while Nord Stream 2 was completed in 2021 but never entered service after Germany withheld opening permission in February 2022.

Source Wikipedia: Nord Stream tier 2

Port of Shanghai, Infrastructure

Standing Scholarly debate

Concerns Completion Year

Currently States 2005

The Port of Shanghai has no single completion date: it developed from an 1842 treaty port into its modern container-shipping form over more than a century. 2005 marks the completion of the Yangshan deep-water port expansion described in the source consulted, not the founding of the port itself.

Source Wikipedia: Port of Shanghai tier 2

Rossiya, Routes and Services

Standing Scholarly debate

Concerns Established Year

Currently States 1965

Sources differ on when the Trans-Siberian's flagship Moscow-Vladivostok through train first carried the Rossiya name and train numbers 1/2; many tertiary sources date the branding to a mid-1960s rebranding, others simply to the completion of continuous through service decades earlier.

Source Wikipedia: Rossiya (train)

Silk Road, Infrastructure

Standing Scholarly debate

Concerns Completion Year

Currently States -114

The Silk Road was a network of routes that grew over centuries rather than a single built work with one completion date. One common marker historians use is the Han dynasty's westward expansion into Central Asia around 114 BCE, though overland trade contacts existed earlier and no single completion date is agreed.

Source Wikipedia: Silk Road tier 2

Walking, Modes

Standing Scholarly debate

Concerns Origin Year

Currently States -3000000

Expressed here as years before present, the same convention this atlas uses for maritime-transport's own undatable origin. Fossil footprint evidence from Kenya suggests hominin ancestors may have walked in broadly modern fashion as long as 3 million years before present, but this is an estimate from a single trackway, not a settled date, and bipedalism itself predates any specific dateable origin of walking as transport.

Source Wikipedia: Walking tier 2