Effects on the economy
Market access
Road infrastructure development lowers the cost of logistics, especially for remote communities. Increased consumer base allows producers, such as farmers, to increase the export of their goods, and thereby increase the flow of money into the industry. Improved road infrastructure has reduced poverty by facilitating higher production and exports in Peru, Bangladesh,[Khandker, S., xa, R, Bakht, Z., Koolwal, G., xa, & B. (2009). The Poverty Impact of Rural Roads: Evidence from Bangladesh. ''Economic Development and Cultural Change, 57''(4), 685-722. doi:10.1086/598765] and parts of Sub-Saharan Africa. Improved market access as a result of improved road infrastructure facilitates a shift from subsistence agriculture
Subsistence agriculture occurs when farmers grow crops on smallholdings to meet the needs of themselves and their families. Subsistence agriculturalists target farm output for survival and for mostly local requirements. Planting decisions occu ...
to increasingly specialized and commercialized agriculture.
Increased commercialization of agriculture results in economic gains for communities, however it can also increase dependence on external markets
and external sources of goods. This has been shown to either result in improved
food security
Food security is the state of having reliable access to a sufficient quantity of affordable, healthy Human food, food. The availability of food for people of any class, gender, ethnicity, or religion is another element of food protection. Simila ...
, as communities are not reliant on their own agricultural capacity, or be detrimental to nutritional status
as communities no longer produce a diverse range of crops.
Facilitating access of remote communities to urban markets can also have the effect of allowing urban market influences to affect rural economies. In the
Democratic Republic of the Congo
The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...
, urban markets are subject to greater control by soldiers than are rural markets, resulting in hunters and farmers paying more
protection money
A protection racket is a type of racket and a scheme of organized crime perpetrated by a potentially hazardous organized crime group that generally guarantees protection outside the sanction of the law to another entity or individual from viol ...
and getting less of a share of profits made.
Greater market intensity is in some instances environmentally detrimental. In the Democratic Republic of the Congo, more large-bodied and endangered animals are hunted for sale in urban markets than in rural markets.
Road construction
Roads must be well designed and constructed to reduce impacts on regional
geomorphology
Geomorphology () is the scientific study of the origin and evolution of topographic and bathymetric features generated by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand wh ...
and
hydrology
Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...
. In undulating terrain, road construction typically proceeds via
cut-and-fill activities, in which high parts of the landscape are cut down and the fill (soil and mineral earth) is
bulldozed into lower areas, in order to flatten-out the topography along the road route. Concurrently,
vegetation
Vegetation is an assemblage of plants and the ground cover they provide. It is a general term, without specific reference to particular Taxon, taxa, life forms, structure, Spatial ecology, spatial extent, or any other specific Botany, botanic ...
is usually cleared along and adjacent to a road footprint. These practices dramatically increase surface
erosion
Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...
and sediment inputs to water courses, altering hydrological patterns, reducing
water quality
Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...
for
human
Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...
s and livestock and elevating water turbidity and
temperature
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...
.
[Sidle, R.C., Ziegler, A.D., 2012. The dilemma of mountain roads. Nature Geosci 5, 437–438.] The altered existing hydrological dynamics resulting from cut and fill activities, inadequate drainage, culverts, and bridges associated with road construction can also obstruct surface-water flow, leading to impeded drainage and localized flooding, particularly during high-rainfall episodes.
Road construction in mountainous areas or steep terrain increases the risks of
landslide
Landslides, also known as landslips, rockslips or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslides ...
s, particularly in wet environments.
Site disturbances, vegetation clearing, unstable terrain caused by cut-and-fill activities, and road drainage all contribute to the elevated rates of landslides in mountainous or steep terrain areas with roads
8 with the likelihood of landslides in close proximity to roads being up to five times higher. In the Brazilian Amazon, ~90% of fires occurred within ≤10 km of roads.
Road construction in forests leads to an increased frequency of fires.
This happens via numerous mechanisms, including intentionally lit fires (leading to
deforestation
Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. Ab ...
), leaked fires from land management practices adjacent to fragmented forests or roads, and accidental fires due to increased human-ignition sources. Increased fire frequency results directly in
biomass
Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...
loss and
carbon emissions
Greenhouse gas (GHG) emissions from human activities intensify the greenhouse effect. This contributes to climate change. Carbon dioxide (), from burning fossil fuels such as coal, petroleum, oil, and natural gas, is the main cause of climate chan ...
, and elevated fire regimes alter the
species composition
Relative species abundance is a component of biodiversity and is a measure of how common or rare a species is relative to other species in a defined location or community.Hubbell, S. P. 2001. ''The unified neutral theory of biodiversity and biogeog ...
and ecological dynamics of susceptible forests.
Traffic and road maintenance
Funding for new road infrastructure in developing nations is focused on initial road construction, with less money being earmarked for ongoing maintenance.
[Alamgir, M., Campbell, M.J., Sloan, S., Goosem, M., Clements, G.R., Mahmoud, M.I., Laurance, W.F., 2017. Economic, socio-political and environmental risks of road development in the tropics. Current Biology 27, R1130-R1140.] With many new roads being constructed in
high-rainfall tropical environments, degradation leading to slumping and pot-holing is rendering expensive paved roads impassable in just a few years. Road degradation increases the cost of using the road, by lengthening travel time or causing damage to vehicles.
Poor quality paved roads may cost less on initial construction, but are more costly to maintain and produce greater costs of use over the life of the road.
Maintaining roads involves long-term and major investments which are subjected to
corrupt
Corruption is a form of dishonesty or a criminal offense that is undertaken by a person or an organization that is entrusted in a position of authority to acquire illicit benefits or abuse power for one's gain. Corruption may involve activities ...
practices of those responsible for maintenance. Moreover, budgeting high construction costs, but building substandard roads which require higher levels of maintenance are both common practice and a major drain on public expenditure and private investment.
Such activities escalate costs and reduce the usable lifetime of roads, and are particularly evident in many developing countries where corruption is more pervasive and implicitly tolerated.
[Mahmoud, M. I., Sloan, S., Campbell, M. J., Alamgir, M., Imong, I., Odigha, O., . . . Laurance, W. F. (2017). Alternative routes for a proposed nigerian superhighway to limit damage to rare ecosystems and wildlife. ''Tropical Conservation Science, 10'', 1940082917709274.][World Bank. (2010). ''Cost-benefit analysis in world bank projects''. Retrieved from Washington, DC ]
Increased road expansion incentivizes people to purchase cars and use roads to a greater extent. This results in further degradation of the roads, leading to higher maintenance costs. Increased use of vehicles and roads leads to more accidents, particularly in regions where roads are of poor quality and motor vehicle use is relatively novel.
More roads result in more traffic, due to
induced demand
In economics, induced demand – related to latent demand and generated demandSchneider, Benjamin (September 6, 2018"CityLab University: Induced Demand"'' CityLab'' – is the phenomenon whereby an increase in supply results in a decline ...
, further increasing the rate of road degradation. As such, economic appraisals of road projects in developing countries often find that improving existing road infrastructure is more beneficial than construction of new road infrastructure.
Effects on societies
Access to services
In developing countries especially, goods and services such as health facilities and educational facilities are often concentrated in urban regions, with little to no availability in remote and rural areas. Road expansion provides greater accessibility to urban centers, and hence improves educational attainment.
In both
Bangladesh
Bangladesh, officially the People's Republic of Bangladesh, is a country in South Asia. It is the List of countries and dependencies by population, eighth-most populous country in the world and among the List of countries and dependencies by ...
and
Madagascar
Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...
investments in improving rural roads have led to greater education attainment. Similarly, greater access to urban areas gives remote communities better access to health facilities, including
medical supplies and medical information, and has been associated with better health outcomes.
Access to urban centers facilitated by road expansion improves employment opportunities. In Indonesia, improved roads allowed job creation in manufacturing industries and an occupational shift amongst workers away from agriculture. Conversely, a greater supply of people seeking employment can drive down the wages in an area, producing a negative effect on livelihoods.
[Grant, U. (2008) Opportunity and exploitation in urban labour markets London: Overseas Development Institute]
While access to goods and services associated with urban centers is beneficial, increased relocation to already densely populated centers increases the strain on cities already struggling to cope with growing populations, particularly in developing regions. Increasing urbanization presents problems including increased crime, increasing inequality, and public health concerns.
Migration and culture
Road expansion leads to
forced migration
Forced displacement (also forced migration or forced relocation) is an involuntary or coerced movement of a person or people away from their home or home region. The United Nations High Commissioner for Refugees, UNHCR defines 'forced displaceme ...
of local peoples, with
indigenous groups
There is no generally accepted definition of Indigenous peoples, although in the 21st century the focus has been on self-identification, cultural difference from other groups in a state, a special relationship with their traditional territ ...
often being highly vulnerable. This happens via the influx of non-indigenous settlers who migrate into the region for employment or to exploit local resources. Non-indigenous settlers can attain or claim the land title through land grabbing, land speculation, and illegal colonization.
[Koji, T., Hoban, C., 1997 Roads and the environment: a handbook, p. 252. The World Bank, Washington, DC.] While migration increases urbanization, potentially leading to increased development, this is at the expense of indigenous populations.
Road expansion is particularly threatening for vulnerable remote communities. Large road projects generate an influx of temporary migrant workers, which increases the demand for services such as prostitution and black-market products.
[Carswell, J.W., 1987. HIV infection in healthy persons in Uganda. AIDS 1, 223–227.] Beyond this, road expansion in remote areas also promotes activities such as illegal logging,
illegal mining
Illegal mining is mining activity that is undertaken without state permission. Illegal mining is the extraction of precious metals/rocks without following the proper procedures to participate in legal mining activity. These procedures include pe ...
, poaching, smuggling and illicit drug production.
Such activities can have chain-reaction-like impacts on the traditional culture and social structure of local communities. The scale and pace of these impacts are most severe in indigenous communities.
The traditional culture and lifestyles of indigenous groups that have lived in remote areas for many generations are substantially altered by new roads. Unprecedented road penetration into their natural landscapes can damage the aesthetic of the landscape and traditional cultural practices, the influx of non-indigenous land settlers violates traditional land rights, and increased commercial poaching alters traditional hunting practices. All such consequences degrade the cultural heritage of indigenous communities, increasing loss of their traditional identity and culture.
Diseases
Temporary workers for road building and the influx of settlers resulting from road building bring new pests and diseases into communities. This mechanism is particularly dangerous for indigenous communities that have limited tolerance and immunity to new
pathogen
In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...
s. For instance, the construction of the
Route 8 in
Bolivia
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...
in the 1970s resulted in the death of 45% of one indigenous community within a single year.
Road expansion increases the incursion of common diseases into communities such as
malaria
Malaria is a Mosquito-borne disease, mosquito-borne infectious disease that affects vertebrates and ''Anopheles'' mosquitoes. Human malaria causes Signs and symptoms, symptoms that typically include fever, Fatigue (medical), fatigue, vomitin ...
and also increase the vulnerability of communities to previously uncommon diseases such as HIV. This occurs as pests and pathogens use roads as a pathway to spread from one place to another place. Human enteric pathogen levels, for instance, were 2–8-times higher in Ecuadorian villages near roads than in more remote areas
and incursions of
dengue fever
Dengue fever is a mosquito-borne disease caused by dengue virus, prevalent in tropical and subtropical areas. Asymptomatic infections are uncommon, mild cases happen frequently; if symptoms appear, they typically begin 3 to 14 days after i ...
, malaria, and HIV were higher among people living near roads than in remote communities.
Conflict
The influx of non-indigenous migrants through road building, and the associated intensification of contact, create inter-group conflicts, such as seen between indigenous
Amazonian tribes and
loggers
Lumberjack is a mostly North American term for workers in the logging industry who perform the initial harvesting and transport of trees. The term usually refers to loggers in the era before 1945 in the United States, when trees were felled us ...
or
gold miner
Gold mining is the extraction of gold by mining.
Historically, mining gold from Alluvium, alluvial deposits used manual separation processes, such as gold panning. The expansion of gold mining to ores that are not on the surface has led to mor ...
s. Additionally, increased road access increases the spread of conflicting forces in war-torn regions, and the pace at which conflicts escalate. In the
Democratic Republic of Congo
The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...
, more accessible regions were exposed to more violent events than less accessible regions resulting in a decrease of population welfare.
Reducing the impacts of road expansion
There are a few ways of reducing its impacts.
Expanding existing roads
Following the 'first-cut-is-the-deepest' dictum, the expansion or upgrading of roads in previously settled areas is believed to cause less environmental impact per kilometer of road development than where new roads penetrate intact forest landscapes. Beyond this rule of thumb, however, road expansion threatens remnant habitats of
endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
and leads to the loss of remnant areas of rare
ecosystem
An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...
s (e.g., lowland tropical forest). This is increasingly common as new major road developments seek to consolidate earlier, rudimentary road networks (often characterized by penetration roads, improvised roads, and rough tracks) to expand agricultural and industrial activities in partially deforested landscapes. Many economic appraisals of road projects in developing countries have found that improving existing road infrastructure is more beneficial than construction of new road infrastructure.
Examples of such consolidative road-expansion projects include the various 'development corridors' of Africa,
meant to facilitate trans-national economic activities;
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...
's development corridors as per its Master Development Plan, meant to accelerate agro-industrial development, mining and timber extraction; and
China's Belt and Road initiative. In northern
Sumatra
Sumatra () is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the list of islands by area, sixth-largest island in the world at 482,286.55 km2 (182,812 mi. ...
, Indonesia, proposed road developments extending the
Trans-Sumatran Highway if they were to occur will affect six of the eight local conservation priority areas of the Leuser Ecosystem, comprising 89% of the remaining
Sumatran orangutan
The Sumatran orangutan (''Pongo abelii'') is one of the three species of orangutans. Critically endangered, and found only in the north of the Indonesian island of Sumatra, it is rarer than the Bornean orangutan but more common than the recently ...
'
s habitat. In fact,
Forest conversion due to road development in this region has been projected as a major factor influencing the decline in
orangutan
Orangutans are great apes native to the rainforests of Indonesia and Malaysia. They are now found only in parts of Borneo and Sumatra, but during the Pleistocene they ranged throughout Southeast Asia and South China. Classified in the genus ...
populations.
Limiting road expansion
Road planning to limit the extension of existing roads in ecologically vulnerable areas or mitigation measures such as restriction of road width and the inclusion of faunal overpasses is an emerging field of
conservation science. Aside from the environmental benefits, limiting road expansion is beneficial for social and economic factors in developing regions. Many roads in remote areas have uncertain socio-economic benefits and surprisingly high economic, social, and environmental risks, and a
cost-benefit analysis of 33 planned 'development corridors' in
sub-Saharan Africa
Sub-Saharan Africa is the area and regions of the continent of Africa that lie south of the Sahara. These include Central Africa, East Africa, Southern Africa, and West Africa. Geopolitically, in addition to the list of sovereign states and ...
concluded that less than one-fifth of the projects were clearly justified.
Many road developments will be characterized by upgrades to rudimentary road networks, rather than entirely new roads.
The Trans-Borneo Highway in
Sabah
Sabah () is a States and federal territories of Malaysia, state of Malaysia located in northern Borneo, in the region of East Malaysia. Sabah has land borders with the Malaysian state of Sarawak to the southwest and Indonesia's North Kalima ...
, Malaysia is one example, as virtually all road developments on this route planned for 2033 will coincide with existing logging roads or two-lane access roadways.
[Ministry of Local Government and Housing (2016). Sabah Structure Plan 2033, (Kota Kinabalu, Sabah, Malaysia: Town and Region Planning Department of Malaysian Ministry of Local Government and Housing).]
Project assessment
The use of more rigorous approaches to project assessment and planning, such as cost-benefit analyses, proactive
land-use planning
Land use planning or ''Land-use regulation'' is the process of regulating the use of land by a central authority. Usually, this is done to promote more desirable social and environmental outcomes as well as a more efficient use of resources. ...
,
and strategic
environmental-impact assessments, is important for the improvement of road developments.
See also
*
Agricultural expansion
Agricultural expansion describes the growth of agricultural land ( arable land, pastures, etc.) especially in the 20th and 21st centuries.
The agricultural expansion is often explained as a direct consequence of the global increase in food and e ...
*
Automotive city
*
Braess's paradox
Braess's paradox is the observation that adding one or more roads to a road network can slow down overall road traffic, traffic flow through it. The paradox was first discovered by Arthur Cecil Pigou, Arthur Pigou in 1920, and Stigler's law of ep ...
*
Freeway removal
*
Highway revolt
*
Road diet
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.
The ...
*
External links
*
James Cook University
James Cook University (JCU) is a public university in North Queensland, Australia. The second oldest university in Queensland, JCU is a teaching and research institution. The university's main campuses are located in the tropical cities of Cair ...
– Centre for Tropical Environmental and Sustainability Science
Reducing the global impacts of rapid infrastructure expansionGlobal Road Maps A strategic approach for advancing nature and sustainability.
Laurance Lab James Cook University
James Cook University (JCU) is a public university in North Queensland, Australia. The second oldest university in Queensland, JCU is a teaching and research institution. The university's main campuses are located in the tropical cities of Cair ...
laboratory website with information about the team and current projects.
Road Free A key website for those concerned about road impacts on wilderness and biodiversity
Alert Conservation:A scientific organization that focuses on tropical forests, wilderness, and environmental conservation issues. Provides links to many topical articles, conservation news, and research.
Conservation Bytes:A lively website for news and opinion about nature conservation.
References
{{Reflist
Roads
Environmentalism
Transportation planning