Editing Northern Ireland (section)

===Infrastructure and transportation===
{{main|Transport in Ireland}}
[[File:Approaching Seahill station - geograph.org.uk - 243422.jpg|thumb|An [[Northern Ireland Railways|NIR]] [[NIR Class 3000|C3K]] [[railcar]]]]
[[File:69, North Junction.jpg|thumb|[[NIR 80 class]] railcar 69, which was used on the [[Peace Train Organisation|Peace Train campaign]] during [[the Troubles]], is preserved at the [[Downpatrick and County Down Railway|Downpatrick & County Down Railway]]]]

Northern Ireland has underdeveloped transport infrastructure, with most infrastructure concentrated around Greater Belfast, Greater Derry, and Craigavon. Northern Ireland is served by three airports—[[Belfast International Airport|Belfast International]] near [[Antrim, County Antrim|Antrim]], [[George Best Belfast City Airport|George Best Belfast City]] integrated into the railway network at [[Sydenham railway station, Northern Ireland|Sydenham]] in East Belfast, and [[City of Derry Airport|City of Derry]] in County Londonderry. There are upgrade plans to transform the railway network in Northern Ireland including new lines from Derry to Portadown and Belfast to Newry, though it will take the best part of 25 years to deliver.<ref>{{Cite news |url=https://www.bbc.co.uk/news/uk-northern-ireland-66297150 |access-date=26 July 2023 |title=All-Island Rail Review: Londonderry to Portadown line recommended |work=BBC News |date=25 July 2023 |archive-date=26 July 2023 |archive-url=https://web.archive.org/web/20230726083037/https://www.bbc.co.uk/news/uk-northern-ireland-66297150 |url-status=live }}</ref> There are major seaports at [[Larne]] and [[Port of Belfast|Belfast]] which carry passengers and freight between Great Britain and Northern Ireland.

Passenger railways are operated by [[NI Railways]]. With [[Iarnród Éireann]] (Irish Rail), [[NI Railways]] co-operates in providing the joint [[Enterprise (train)|Enterprise]] service between [[Dublin Connolly]] and [[Belfast Grand Central station|Belfast Grand Central]]. The whole of Ireland has a mainline railway network with a [[Track gauge in Ireland|gauge of {{cvt|5|ft|3|in|mm}}]], which is unique in Europe and has resulted in distinct rolling stock designs. The only preserved line of this gauge on the island is the [[Downpatrick and County Down Railway]], which operates heritage steam and diesel locomotives. Main railway lines linking to and from [[Belfast Grand Central station|Belfast Grand Central Station]] and Lanyon Place railway station are:
* The [[Belfast–Derry railway line|Derry Line]] and the Portrush Branch.
* The [[Larne Town railway station|Larne]] Line
* The [[Bangor railway station (Northern Ireland)|Bangor]] Line
* The [[Newry railway station|Newry]]/[[Portadown railway station|Portadown]] Line

The Derry line is the busiest single-track railway line in the United Kingdom, carrying 3 million passengers per annum, the Derry-Londonderry Line has also been described by Michael Palin as "one of the most beautiful rail journeys in the world".<ref>{{Cite news |url=https://www.belfasttelegraph.co.uk/news/northern-ireland/michael-palins-favourite-railway-line-between-coleraine-and-derry-in-northern-ireland-set-to-re-open-following-upgrade/35227689.html |access-date=26 July 2023 |title=Michael Palin's favourite railway line - between Coleraine and Derry in Northern Ireland |newspaper=Belfasttelegraph.co.uk |date=18 November 2016 |archive-date=26 July 2023 |archive-url=https://web.archive.org/web/20230726073856/https://www.belfasttelegraph.co.uk/news/northern-ireland/michael-palins-favourite-railway-line-between-coleraine-and-derry-in-northern-ireland-set-to-re-open-following-upgrade/35227689.html |url-status=live }}</ref>

Main motorways are:
* [[M1 motorway (Northern Ireland)|M1]] connecting Belfast to the south and west, ending in [[Dungannon]]
* [[M2 motorway (Northern Ireland)|M2]] connecting Belfast to the north. An unconnected section of the [[M2 motorway (Northern Ireland)|M2]] also by-passes [[Ballymena]]

Additional short motorway spurs include:
* [[M12 motorway (Northern Ireland)|M12]] connecting the [[M1 motorway (Northern Ireland)|M1]] to [[Portadown]]
* [[M22 motorway (Northern Ireland)|M22]] connecting the [[M2 motorway (Northern Ireland)|M2]] to near [[Randalstown]]
* [[M3 motorway (Northern Ireland)|M3]] connecting the M1 (via the [[Westlink (road)|A12]]) and M2 in Belfast with the A2 dual carriageway to [[Bangor, County Down|Bangor]]
* [[M5 motorway (Northern Ireland)|M5]] connecting Belfast to [[Newtownabbey]]

The cross-border road connecting the ports of [[Larne]] in Northern Ireland and [[Rosslare Harbour]] in the Republic of Ireland is being upgraded as part of an EU-funded scheme. [[European route E01]] runs from Larne through the island of Ireland, Spain, and Portugal to [[Seville]].