Editing Tram (section)

===Routes===
[[File:Île-de-France - plan des tramways.png|thumb|A map of the tram routes of [[Paris]].]]
Route patterns vary greatly among the world's tram systems, leading to different [[Transport topology|network topologies]]. 
* Most systems start by building up a strongly nucleated radial pattern of routes linking the city centre with residential suburbs and traffic hubs such as railway stations and hospitals, usually following main roads. Some of these, such as those in [[Hong Kong Tramways|Hong Kong]], [[Blackpool tramway|Blackpool]] and [[Bergen Light Rail|Bergen]], still essentially comprise a single route. Some suburbs may be served by loop lines connecting two adjacent radial roads. Some modern systems have started by reusing existing radial railway tracks, as in [[Nottingham Express Transit|Nottingham]] and [[West Midlands Metro|Birmingham]], sometimes [[Cross-city route|joining them together]] by a section of street track through the city centre, as in [[Manchester Metrolink|Manchester]]. Later developments often include tangential routes linking adjacent suburbs directly, or multiple routes through the town centre to avoid congestion (as in Manchester's [[Manchester Metrolink#Phase 2CC – Second City Crossing|Second City Crossing]]).
* Other new systems, particularly those in large cities which already have well-developed metro and suburban railway systems, such as [[Tramlink|London]] and [[Tramways in Île-de-France|Paris]], have started by building isolated suburban lines feeding into railway or metro stations. In Paris these have then been linked by [[Circle route|ring lines]].
* A third, weakly nucleated, route pattern may grow up where a number of nearby small settlements are linked, such as in the coal-mining areas served by [[BOGESTRA]] or the [[Silesian Interurbans]].
* A fourth starting point may be a loop in the city centre, sometimes called a [[downtown circulator]], as in [[Portland Streetcar|Portland]] or [[El Paso Streetcar|El Paso]].
* Occasionally a modern tramway system may grow from a preserved heritage line, as in [[Trams in Stockholm|Stockholm]].

The resulting route patterns are very different. Some have a rational structure, covering their catchment area as efficiently as possible, with new suburbs being planned with tramlines integral to their layout – such is the case in [[Trams in Amsterdam|Amsterdam]]. [[Bordeaux Tramway|Bordeaux]] and [[Montpellier tramway|Montpellier]] have built comprehensive networks, based on radial routes with numerous interconnections, within the last two decades. Some systems serve only parts of their cities, with [[Trams in Berlin|Berlin]] being the prime example, as trams survived the city's political division only in the Eastern part. Other systems have ended up with a rather random route map, for instance when some previous operating companies have ceased operation (as with the ''tramways vicinaux/buurtspoorwegen'' in [[Trams in Brussels|Brussels]]) or where isolated outlying lines have been preserved (as on the eastern fringe of Berlin). In [[Trams in Rome|Rome]], the remnant of the system comprises three isolated radial routes, not connecting in the ancient city centre, but linked by a ring route. Some apparently anomalous lines continue in operation where a new line would not on rational grounds be built, because it is much more costly to build a new line than to continue operating an existing one.

In some places, the opportunity is taken when roads are being repaved to lay tramlines (though without erecting overhead cables) even though no service is immediately planned: such is the case in [[Leipziger Straße|Leipzigerstraße]] in Berlin, the Haarlemmer Houttuinen in Amsterdam, and Botermarkt in Ghent.

====Cross-border routes====
Tram systems operate across national borders in [[Trams in Basel#Cross-border routes|Basel]] (from Switzerland into France and Germany), [[Trams in Geneva|Geneva]] (from Switzerland into France) and [[Strasbourg tramway#Future extensions|Strasbourg]] (from France into Germany).

In 2012, plans were made to connect the Polish town of [[Słubice]] to the tram network of [[Trams in Frankfurt (Oder)|Frankfurt an der Oder]]. These plans were cancelled when voters in Frankfurt voted down funding for the project and replaced the tram line with a bus. <ref>{{cite web |title=Dream of tram line to Słubice over|url=https://www.transport-publiczny.pl/wiadomosci/koniec-marzen-o-tramwaju-ze-slubic-do-frankfurtu-51679.html|date=29 March 2016|language=pl-PL}}</ref> Another cross-border tramway that was planned [[Hasselt – Maastricht tramway|linking Hasselt (Belgium) with Maastricht (Netherlands)]] was cancelled in June 2022.