Roads to Infinity: The Longest Highways in the World

From primitive prehistoric pathways to modern motorways, the rise of roads has been a defining feature of the complex story of human civilisation, shaping societies, economies, and cultures. But where are the world’s longest roads, and which is the widest road in the world? Buckle up, let’s find out.

Building Big Engineering
2 February 2024

The world’s road networks are a marvel of engineering. Some are as short as a few metres, others are long. Very long. The longest highways in the world connect cities, countries, and continents, embodying an innate desire to explore and connect.

The evolution of roads has mirrored the advancement of technology, from simple dirt paths where early humans would follow the tracks of animals, to the first paved roads in Egypt around 2600 BC. These early innovations set the stage for what would become an extensive network of roads, connecting villages, towns, cities, countries, continents and civilisations.

They facilitated trade, military movements, and cultural exchange, effectively shrinking the world bit by bit. As civilisations grew, the importance of roads magnified, especially with the advent of vehicles. No longer just paths for feet and hooves, the world’s longest roads became the arteries of commerce and daily life, accommodating a range of vehicles from horses to hypercars, and enabling societies to move and thrive.

Here are the longest highways in the world.

Measuring the Biggest Highways in the World

An aerial sunset view of a multi-lane highway intersection. (Credit: Karl Hendon via Getty Images)

Charting the longest roads and longest motorways in the world is a complex and challenging task and indeed there are several approaches to this task.

Variation by Type

Roads around the world vary significantly in type and purpose. They range from motorways and highways designed for high-speed traffic to rural roads. This makes it difficult to compare roads based solely on length, as the nature and function of these roads can be vastly different.


Not all roads are continuous. Some of the biggest highways in the world are interrupted by natural features like rivers, mountains, or man-made structures like tunnels and bridges. In some cases, these interruptions might require alternate modes of transport to continue along the same route. This discontinuity poses a challenge in measuring the true length of a road as a singular entity.


In certain instances, a section of a road will be part of multiple routes. This overlapping can complicate the measurement of a road’s total length. For instance, a stretch of road may simultaneously be part of a national highway and a regional road, leading to discrepancies in how its length is accounted for in different contexts.

There are other factors, including the fact that the longest highways in the world are dynamic structures, often undergoing changes, extensions, or rerouting due to construction, environmental elements, and urban development. In addition, there isn’t a globally-accepted standard for measuring the length of roads, especially as the planet’s longest roads traverse cities, countries and even continents.

Due to these factors, compiling a definitive list of the world’s longest roads is not only challenging but also subject to interpretation and change over time. Despite this however, there are a number of contenders that are worth examining when it comes to the world’s longest roads.

Golden Quadrilateral | 5,846 km / 3,633 mi

Riding the Golden Quadrilateral Highway in India (Credit: Ramnath Bhat / Contributor via Getty Images)

India’s Golden Quadrilateral highway network connects the four major metro cities – Delhi in the north, Kolkata in the east, Mumbai in the west, and Chennai in the south – is one of the longest highways in the world.

The highways within the network range from two to six lanes and the system as a whole was completed in May 2013. It was originally conceived as an easier way for people in rural parts of India to bring their agricultural goods to markets in the big cities.

Trans-Canada Highway | 7,476 km / 4,645 mi

The Trans-Canada highway in Jasper National Park, Alberta, Canada. (Credit: lucky-photographer via Getty Images)

One of the world’s longest roads, the Trans-Canada Highway connects the Pacific Ocean in the west with the Atlantic Ocean in the east. It’s believed to be the longest continuous highway in the world and passes through each of the ten Canadian provinces.

The TCH – which officially opened in 1962 – is famous for its road signs, a white maple leaf on a green background, and much of the route follows the tracks of the historic Canadian Pacific Railway.

Trans-Siberian Highway | 11,000 km / 6,800 mi

Russia, Siberia, Baikal Lake, Trans-siberian train. (Credit: Tuul & Bruno Morandi via Getty Images)

Another of the biggest highways in the world is Russia’s Trans-Siberian Highway running from the Baltic Sea at St. Petersburg in the west, all the way to the Pacific Ocean at Vladivostok in the east.

Much of the road network follows the route of the famous Trans-Siberian Railway and is made up of a number of separate, yet connected highways including the M10 from St. Petersburg to Moscow, and the famed R297, or the Amur Highway, from Chita to Khabarovsk in the Russian Far East.

Highway 1 | 14,523 km / 9,024 mi

Highway 1 passing through Western Australia (Credit: travellinglight via Getty Images)

Australia’s Highway 1 is one of the longest highways in the world. It also has the distinction of being the longest road contained within a single country and one of the longest motorways in the world. Like many of the other longest roads on this list, Highway 1 is a joined-up network of motorways and smaller roads rather than a single road.

Affectionately called The Big Lap, Highway 1 connects all of Australia’s state capitals except Canberra, and it’s believed over one million Australians use it every day.

Pan-American Highway | 25,000 km / 15,534 mi - 48,000 km / 29,800 mi

The Pan-American Highway. (Credit: Igor Alecsander via Getty Images)

Generally considered to be the longest road in the world, the Pan-American Highway is an integrated network of highways and arterial roads stretching from Prudhoe Bay in Alaska in the north, to Ushuaia in Argentina, one of the world’s southernmost cities.

Guinness World Records calls the Pan-American Highway the ‘world’s longest motorable road’ but the length varies so dramatically due to the fact that it’s an incredibly complex series of roads, highways and interconnected branch routes and many – some unofficial – are often counted more than once.

In addition, there’s a non-drivable section of around 106 km (66 mi) straddling the border of Colombia and Panama called the Darién Gap, and each country it passes through has its own criteria for measurement.

It travels through fourteen countries – Canada, USA, Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Ecuador, Peru, Chile and Argentina – and some of the major spurs reach into Bolivia, Brazil, Paraguay and Uruguay.

The World’s Longest Motorways

Seattle highway night trails. (Credit: Michael Lee via Getty Images)

Called highways or expressways in various parts of the world, most of the world’s longest motorways are in the USA and China. These refer to individual, distinct highways as opposed to a series of interconnected road networks.

The longest motorway in the world is Interstate 90 which runs from Seattle, Washington to Boston, Massachusetts at 4,861 km (3,020 mi). This is closely followed by I-80 at 4,666 km (2,899 mi) running from San Francisco, California, to Teaneck, New Jersey.

Interstate 40 runs from Barstow, California to Wilmington, North Carolina and is 4,119 km (2,559 mi) long, and Interstate 10 is 3,960 km (2,460 mi) long and stretches from Santa Monica, California to Jacksonville, Florida.

China’s longest motorway is the 4,395 km (2,731 mi) G30 Lianyungang-Khorgas Expressway, which runs from Lianyungang on the east coast to the autonomous region of Xinjiang on the border with Kazakhstan.

By way of comparison, the longest motorways in the UK are the M6 from the Midlands to the Scottish border at 370 km (230 mi), and the M1 connecting London to Leeds at 311 km (193 mi).

The Widest Road in the World

Houston Katy Freeway in Texas, USA. (Credit: LUNAMARINA via Getty Images)

As well as being one of the biggest highways in the world, a section of Interstate 10 – known locally as the Katy Freeway as it runs through the western Texas suburb of Katy – is the widest road in the world, with a maximum width of twenty-six lanes.

It has a basic configuration of fourteen lanes – seven in each direction – and includes feeder (or frontage) roads, and HOV (High-Occupancy Vehicle) lanes. This expansive width is primarily to accommodate the heavy traffic flow in downtown Houston, making it a standout example of large-scale urban motorway infrastructure.

The Katy Freeway’s extensive width is designed to manage the significant traffic demands in one of the USA’s busiest metropolitan areas.

The Journey’s End: The Longest Roads in the World

A long straight road found in Tierra del Fuego, Argentina. (Credit: rawfile redux via Getty Images)

The longest highways in the world are more than just feats of engineering. They are the lifelines of civilisation, connecting cultures, economies, and people across the globe.

From the historic routes that have witnessed the passage of time to the modern motorways that symbolise progress, each road tells a unique story.

Whether it’s the legendary Pan-American Highway, weaving through diverse landscapes and nations, or the expansive transcontinental routes that stretch across entire continents, the biggest highways in the world remind us of the endless possibilities and unexplored frontiers that lie just over the horizon.


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