Major growth in road projects can be disastrous for economy: Study

"Many roads that are planned for wet, swampy or mountainous regions should not be built, and that is based only on economic criteria," said William Laurance

The massive growth of major road projects across the world can be potentially disastrous for the environment and the economy, a study warns.

Researchers analysed major roads and infrastructure projects around the world.

"We have scrutinised major roads and infrastructure projects around the world, and it is remarkable how many have serious hidden costs and risks," said William Laurance, professor at James Cook University in Australia.

According to the study, published in the journal Science, the most urgent priority is limiting millions of kilometres of new roads being planned or built in high-rainfall areas, mostly in developing nations of the Asia-Pacific, Africa and Latin America.

This is where ambition for quick profits meets nearly impossible engineering. Rainfall-drenched roads develop pot- holes, giant cracks and landslides so fast it is nearly unbelievable. They can quickly turn into giant money-losers, researchers said.

"Many roads that are planned for wet, swampy or mountainous regions should not be built, and that is based only on economic criteria," said Laurance.

"If you add in environmental and social costs, then the pendulum swings even harder against new roads, especially in forested areas with high environmental values," said Irene Burgues Arrea, an economist with the Alliance of Leading Environmental Researchers and Thinkers (ALERT) in Costa Rica.

By the year 2050, it is projected that there will be an additional 25 million kilometres of new paved roads on Earth - enough to encircle the planet more than 600 times, researchers said.

In just the next three years, paved roads are expected to double in length in Asia's developing nations, they added.

"The public often ends up with major debts from failed roads. A few road developers and politicians get rich, but vital development opportunities are easily squandered," said Laurance.

"It is remarkable how many nations, investors, and lenders are failing to see the profound risks of road expansion in wet tropical environments, which are also the world's biologically richest ecosystems," Laurance added.