Living in Europe I would imagine that in theory, and probably in practice, I could hit the road with a car and drive all the way to e.g. Malaysia, because the road network consists of "millions" of roads connected to each other so that I could eventually hit my destination by just driving. Other land masses besides Afro-Eurasia have their own mainland-wide road networks which likely connect the distinct points of the continent. The same goes with islands such as New Zealand and Australia.

I'm interested in where I can find the largest road network that shares a landmass with, but is disconnected from, a larger ('main') road network?

enter image description here

In this example there is a primary road network (in black) in a land and an additional road network (in green) which isn't connected to the land's primary road network.

To define how roads are connected, roads connected by a bridge or by unpaved road count as a connection, but e.g. ferry connections do not count (as one can't drive continuously from one end to other - however if the ferry takes you to an island, the road network would be part of another land mass's road network).

The US's gaps in Interstate Highways seem like a case where the roads are still connected to each other, so they likely do not provide a sufficient answer. I have read of cities that have been built in the "middle of nowhere" which could have independent road networks. Also vast land masses with a challenging nature such as Antarctica or Greenland possibly have separate road networks which are not connected to each other nor to any other land mass. Maybe one of these could be the answer to the question.

  • @MichaelSeifert: "longest road network" - I'd imagine this unambiguous, a network of roads (both paved and unpaved) which is the longest in its category (i.e. your 2nd definition) (see e.g. wiki); and ferry connections do not count as they break the road network.
    – moe
    Commented Jan 2, 2018 at 12:57
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    I'm voting to close this question as off-topic because it is a geography trivia question that is unrelated to actual travel. Commented Jan 2, 2018 at 22:47
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    @DavidRicherby there exists dozens of similar question on travel.SE which many of them are tagged as where-on-earth. Similar questions have received the same criticism, but for what I've seen, approved to be part of this community. Additionally I'm actually interested in visiting a place like this.
    – moe
    Commented Jan 3, 2018 at 5:36
  • Comments are not for extended discussion; this conversation has been moved to chat.
    – JoErNanO
    Commented Jan 3, 2018 at 11:43

9 Answers 9


South America is physically connected to North America, but there's a jungle/marsh area in the middle that has no roads through it (the Darién Gap). Several people have crossed the Gap, but this is a major expedition. Most took at least 30 days to travel the 100 km length of the Gap.
There are several bridges across the Panama Canal, so Panama north of the Gap is connected to the US. The Canal is man-made, so I don't consider that as separating 2 landmasses.

  • It's a bit shame the right answer is this notable network, but due to Darién Gap this meets the "rules" I've set. I guess South America's road network is shorter and is therefore the underlined answer to the question.
    – moe
    Commented Jan 2, 2018 at 18:47
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    How can North and South America be physically connected if it is possible to travel by PANAMAX sized ship between them? - Oooh, I see. The gap is elsewhere. And there I though I was always passing betwwn N and S along the Canal ... Commented Jan 2, 2018 at 21:30

At first I thought this was ridiculous. How would cars get to the green area? Then I remembered the far north of Canada, my own country. Isolated villages and towns have roads with cars on them, but are not connected to the main road system. Cars come in by train or boat.

Here are Moosonee and Moose Factory:

enter image description here

You can see they distinctly have a road system. It is not connected to other roads in Canada and you cannot drive to Moosonee. You can drive between these in the winter on an ice road, but not in the summer.

Random facts: A factory is to a factor as a rectory is to a rector - while the word is now applied to "a place where things are made" that was not the original meaning. Moose Factory is among the oldest permanent settlements in Canada. I have been to both towns and saw no moose. Also this "far north" place is at the same latitude as London, UK, and Berlin, DE.

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    Good fact on the factory tidbit. As someone who has never heard that terminology, I was under the assumption that it was an industrial city named after some sort of company named "Moose".
    – Anoplexian
    Commented Jan 2, 2018 at 16:58
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    I'm still confused what a "Moose Factor" would be? Commented Jan 2, 2018 at 17:12
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    @KateGregory I think the issue is that "factor" in this sense (one for which "place where a factor lives" actually makes sense) is not commonly used in most varieties of modern English. M-W tells me the relevant meaning is likely "one who acts or transacts business for another". (Versus definitions 2&4, which I'm guessing are what most people think of when hearing "factor").
    – R.M.
    Commented Jan 2, 2018 at 17:45
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    From Wikipedia: "The term 'Factory' refers to the jurisdiction of a factor (a business agent or merchant in charge of buying or selling) of the Hudson's Bay Company." Not as exciting as I originally thought, a place where horses are taken, given extra fur and a nice big set of antlers.
    – BruceWayne
    Commented Jan 2, 2018 at 17:50
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    @Criggie A series of communities north of Moosonee are interconnected in winter via a winter road that is re-constructed each year once the ground freezes. There is no winter road to Moosonee at any time of year, though - the rail line to Cochrane provides land transportation to the rest of the national road network. These communities aren't on an island; they're on the main north american landmass. There is a winter ice road between Moosonee and Moose Factory, but this only connects them to each other, not to the rest of the country.
    – J...
    Commented Jan 2, 2018 at 20:29

Juneau, Alaska would be a definite candidate. The city is at sea level and surrounded by mountains that isolate it from the mainland of North America despite being connected by land.

  • I was thinking the same exact thing. Commented Jan 2, 2018 at 16:48
  • That seems to be the case! I'd imagine this forms one of the longest networks, especially if we don't count the possibility of North & South America.
    – moe
    Commented Jan 2, 2018 at 18:35

Due to the Darién Gap I believe the answer you're looking for is the north and south half of the Pan-American Highway. The Darién Gap is a 66 mile long break in a 19,000 mile long road system not to mention the road networks that connect to the Pan-American Highway in the north and south.

Of course this doesn't match your diagram of an island of roads encircled by a larger network of roads but it should match the rules you described.

  • Same answer as travel.stackexchange.com/a/107684/324 , but posted about 9 seconds afterwards? Really bad luck.
    – Golden Cuy
    Commented Jan 2, 2018 at 21:36
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    @AndrewGrimm yes and I voted for the other answer right when I noticed it so it was above mine and collected significantly more votes. I wasn’t quick enough on the draw but such is life. The op got their answer though so that’s the main thing. :)
    – Erik
    Commented Jan 2, 2018 at 21:42


A good candidate (if North/South America is not counted) may be the Kamchatka Peninsula in the Russian Far East. According to Open Street Map there seems to be a highway system connecting cities as far apart as Palana in the north, and Petropavlovsk-Kamchatsky and Ust-Bolsheretsky in the south (closer inspection using Bing Maps indicates that there seems to be a road connection as far south as Ozernovskiy). This would mean that the road network covers an area stretching about 900 km from north to south, and about 400 km west to east. This network is almost certainly not connected to the main Eurasian road network. The total length of the network is probably much harder to estimate. The total population in Kamchatka is around 300,000 people (although some of them may not be connected to the main road network).


  • 4
    Petropavlovsk-Kamchatsk is actually the second largest city in the world that cannot be reached by roads connecting it to the rest of its landmass - Iquitos, Peru, being the largest.
    – J...
    Commented Jan 3, 2018 at 12:57

The road to Cape Wrath is isolated from the rest of the Scottish road network by the Kyle of Durness - it can be crossed by driving across the beach at low tide. If that's not enough, the area is also a live missile range. It's about 14km as the crow flies from Cape Wrath to the Kyle of Durness.

  • It's inconceivable that this tiny example could be the largest in the world. Especially since examples that are orders of magnitude larger were posted before this. Commented Jan 2, 2018 at 22:50
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    The Cape of Wrath is a great name for an area with a missile range.
    – Erik
    Commented Jan 3, 2018 at 15:44

If I'm understanding the rules correctly, the answer is almost certainly the road network of Japan. The entire nation of Japan has 1.2 million kilometers of roads, which makes it the nation with the sixth-largest road network in the world. While some of these roads are presumably on outlying islands (such as the Ryukyu Islands) that are disconnected from the main Japanese road network, the great majority of these roads are on the four main islands of Honshu, Hokkaido, Shikuko, and Kyushu, as well as on other small islands connected to these by bridges.

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    I'm afraid I've failed in defining the rules. Japan is a group of islands some of them being connected to each other with bridges. An island's road network is independent and not connected e.g. in Japan's case to Asia. Yet it still forms its own mainland's primary network (= the longest road network to its land). In this graph I attempt to illustrate how there can be a primary road network (in black) in a land and an additional road network (in green) which isn't connected to the land's primary road network. I hope it clarifies.
    – moe
    Commented Jan 2, 2018 at 13:36
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    @moe: The picture makes things a lot clearer; the use of "mainland" in the question statement made me think you were looking for road networks on islands. Would it be correct to say that you're looking "the largest road network that shares a landmass with, but is disconnected from, a larger ('main') road network"? Commented Jan 2, 2018 at 14:08
  • That's exactly the wording that does the job! Time to clarify the original question.
    – moe
    Commented Jan 2, 2018 at 14:23
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    @moe: You might want to explicitly disqualify the North America/South America case in your revised question statement, as otherwise that would be the answer. Commented Jan 2, 2018 at 14:32
  • If there is no road between Darién Gap and it splits the road network of the continent of America into two, I can take it as an answer. Then it's a matter of defining whether Panama's area narrows the road network between the canal's southern part and the Darién Gap, or does the road network go all the way to the North America. However, if Darién Gap has a connecting road and only Panama splits America, as a water border, it splits the landmasses into two and thus into two individual "main" road networks.
    – moe
    Commented Jan 2, 2018 at 14:49

Sfantu Gheorghe in the Danube Delta covers an area a little less than 4 by 2 kilometers.
There are cars there, but you have to bring them by riverboat.


Not a winner, but still of significant distance at probably almost 600 km at times would be the

Tibbitt to Contwoyto Winter Road

A 600 km long stretch of road built each year over non permanent ice.

Whilst it is built each January from South to North (leaving no length unconnected to the main N America road system), it is likely to generally melt each spring from South to North, leaving much or most of the length unconnected.

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