A dirt road or track is a type of

unpaved A road surface (British English) or pavement (North American English) is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past, gravel road surfaces, macadam, ho ...

road A road is a thoroughfare used primarily for movement of traffic. Roads differ from streets, whose primary use is local access. They also differ from stroads, which combine the features of streets and roads. Most modern roads are paved. Th ...

not paved with asphalt, concrete, brick, or stone; made from the native material of the land surface through which it passes, known to highway engineers as

subgrade In transport engineering, subgrade is the native material underneath a constructed road,http://www.highwaysmaintenance.com/drainage.htm The Idiots' Guide to Highways Maintenance ''highwaysmaintenence.com'' pavement or railway track (US: railroad ...

material.

Terminology

Similar terms

Terms similar to dirt road are ''dry-weather road'', ''earth road'', or the "Class Four Highway" designation used in

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. A ''track'', ''dirt track'', or ''earth track'' would normally be similar but less suitable for larger vehicles—the distinction is not well-defined. Laterite and murram roads, depending on material used, may be dirt roads or improved roads.

Improved road

Unpaved roads with a harder surface made by the addition of material such as

gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

and aggregate (stones), might be referred to as dirt roads in

common usage The usage of a language is the ways in which its written and spoken variations are routinely employed by its speakers; that is, it refers to "the collective habits of a language's native speakers", as opposed to idealized models of how a languag ...

but are distinguished as improved roads by highway engineers. Improved unpaved roads include

gravel road A gravel road is a type of unpaved road surfaced with gravel that has been brought to the site from a quarry or stream bed. Gravel roads are common in less-developed nations, and also in the rural areas of developed nations such as Canada and ...

s and macadamized roads.

Characteristics

Compared to a gravel road, a dirt road is not usually graded regularly to produce an enhanced camber to encourage rainwater to drain off the road, and drainage ditches at the sides may be absent. They are unlikely to have embankments through low-lying areas. This leads to greater waterlogging and erosion, and after heavy rain the road may be impassable even to

off-road vehicle An off-road vehicle (ORV), also known as an off-highway vehicle (OHV), overland vehicle or adventure vehicle, is a type of transportation specifically engineered to navigate unpaved roads and surfaces. These include trails, forest roads, and ...

s. For this reason, in some countries, such as

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

and

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

, they are known as ''dry-weather roads''. Dirt roads take on different characteristics according to the

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

s and

geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...

where they pass, and may be sandy, stony, rocky or have a bare earth surface, which could be extremely muddy and slippery when wet, and baked hard when dry. They are likely to become impassable after rain. They are common in

rural area In general, a rural area or a countryside is a geographic area that is located outside towns and cities. Typical rural areas have a low population density and small settlements. Agricultural areas and areas with forestry are typically desc ...

s of many countries, often very narrow and infrequently used, and are also found in

metropolitan area A metropolitan area or metro is a region consisting of a densely populated urban area, urban agglomeration and its surrounding territories which share Industry (economics), industries, commercial areas, Transport infrastructure, transport network ...

s of many developing countries, where they may also be used as major highways and have considerable width. Dirt roads almost always form a washboard-like surface with ridges. The reason for this is that dirt roads have tiny irregularities; a wheel hitting a bump pushes it forward, making it bigger, while a wheel pushing over a bump pushes dirt into the next bump. However, the surface can remain flat for velocities less than .

Driving on dirt roads

While most gravel roads are all-weather roads and can be used by ordinary

car A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people rather than cargo. There are around one billio ...

s, dirt roads may only be passable by

truck A truck or lorry is a motor vehicle designed to transport freight, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construct ...

s or

four-wheel drive A four-wheel drive, also called 4×4 ("four by four") or 4WD, is a two-axled vehicle drivetrain capable of providing torque to all of its wheels simultaneously. It may be full-time or on-demand, and is typically linked via a transfer case pr ...

vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...

s, especially in wet weather, or on rocky or very sandy sections. It is as easy to become bogged in sand as it is in mud; a high clearance under the vehicle may be required for rocky sections. Driving on dirt roads requires great attention to variations in the surface and it is easier to lose control than on a gravel road.

Image gallery

File:Dirt Road - Fremont - CA.jpg, Dirt road in

Fremont, California Fremont () is a city in Alameda County, California, United States. Located in the East Bay region of the San Francisco Bay Area, Bay Area, Fremont has a population of 230,504 as of 2020, making it the fourth List of cities and towns in the San F ...

File:655 Wrightwood Avenue Circa 1880, Lincoln Park Chicago Illinois.jpg, Wrightwood Street in

Lincoln Park neighborhood Lincoln Park is a designated community area on the North Side of Chicago, Illinois. It is located west of Lincoln Park. History In 1824, the United States Army built a small post near today's Clybourn Avenue and Armitage Avenue (former ...

Chicago Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...

, Illinois, File:Frühlingslandschft Aaretal Schweiz.jpg, Mountain track in Switzerland File:DryDirtRoadDetail.jpg, Detail of a dry, loamy road File:Bike on the rough roads in Bagamoyo.jpg, Cycling on a rough road in

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

File:Le transport au Bénin 01.webm, Spraying dirt road with water in

Benin Benin, officially the Republic of Benin, is a country in West Africa. It was formerly known as Dahomey. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the north-west, and Niger to the north-east. The majority of its po ...

File:Bowerman Road Kingsley MI.jpg, Rural dirt road near Kingsley,

Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...

File:DirtRoadByAmiltonReis.jpg, Dirt road in

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...