The Tanzanian government is moving forward with plans to build a public road through Serengeti National Park, despite conservationists' concerns that commercial traffic will disrupt the annual wildebeest migration and allow poachers better access into the park.

During the migration, more than a million wildebeest follow a circular path through the Serengeti and up into Maasai Mara National Reserve in Kenya, chasing grass and water as the seasons change. (Watch video previews of Great Migrations, a new series airing soon on the National Geographic Channel.)

"Creating a commercial road through such a natural environment—where millions of wildebeest migrate annually—will be an intrusion in the natural habitat, so much so that the level of stress [among the animals] will be tremendous," said Steven Kiruswa, the Maasai Steppe Heartland Director at the African Wildlife Foundation.

Despite conservationists' concerns, Tanzanian President Jakaya Kikwete said in a speech in late July that the government plans to go ahead with the road, which was one of the promises he made to voters during the run-up to elections in 2005.

Officials say the road will boost the national economy by connecting growing communities in the northwest with the rest of Tanzania.

Kikwete said he has heard about opposition to the road, which he said was "aired by people from abroad."

"I want to assure them that I am also a staunch supporter of the environment and will be the last person to allow something which is going to destroy the nature," Kikwete said.

A conservation official based in Tanzania, however, says that the government has told staff at Tanzania National Parks (TANAPA) to keep their concerns about the project quiet.

"Nobody in National Parks is supportive, but the president told them they have to be in line," said the conservationist, who spoke anonymously for fear of retribution from the government.

Road Would Kill Migrating Species?

Under the current proposal, the new road would connect the growing population along Lake Victoria to the city of Arusha—the staging ground for tourists looking to climb Mt. Kilimanjaro—and to the rest of Tanzania (see map).

Currently the only suitable road for commercial traffic sweeps well below Serengeti National Park's southern boundary, which means towns in the northwest are largely isolated.

The proposed road would include a 33-mile (54-kilometer) stretch cutting through the park. The road and a 164-foot (50-meter) buffer zone on each side would no longer be designated as park land, so that commercial trucks could pass through.

Debate over a road through the Serengeti has gone on for years, largely because of concerns that traffic along the road would disrupt the wildebeest migration. (See related pictures of "surprise" herds found in Sudan.)

The World Bank rejected a proposal that it fund a similar road in the 1980s because of the road's potential ecological impacts.

Given the Serengeti's status as a UNESCO World Heritage site, a road through the park would "contravene the purpose of Tanzania's accession to the World Heritage Convention," according to the World Bank. The road would also "cause massive mortality of migratory species" and diminish the Serengeti's value as a tourist attraction.

An environmental-impact assessment conducted by a Norwegian consulting company in 1996 looked at several road proposals, and the report uniformly advised against building roads through the Serengeti. Another assessment by a Tanzanian consultancy in 2007, meanwhile, reported that the effects on wildlife could be mitigated.

Yet another round of environmental-impact and feasibility studies will be finished in December, according to TANAPA spokesperson Pascal Shelutete. Until then, the parks official declined to comment on the proposed project or the environmental concerns.

"TANAPA being a government institution, we work hard to make sure the government decision is being fulfilled. But before construction begins, the feasibility study must be done as well as the environmental-impact assessment," Shelutete said in a phone interview.

"It's a government decision, and we have to obey what the government is doing."

Senior government officials have addressed some concerns in interviews with Tanzanian media.

Shamsa Mwangunga, Tanzania's minister for natural resources and tourism, told The East African newspaper that the road project "will not interfere with the Serengeti ecosystem and the spectacular wildlife migration, as the green activists claim."

Government officials say construction of the road is expected to begin in 2012.

Road Would Invite Poachers, Lion Killings?

Some conservationists have suggested building tunnels underneath the road for wildebeest to pass, but that sort of infrastructure project would be massive and expensive. Others have proposed alternate routes to address the need for a thoroughfare while protecting the Serengeti.

Ecologist Anthony Sinclair, one of the world's foremost experts on the Serengeti, said a road hugging the park's southern border would be longer than the currently proposed road but would serve more people, because it would pass through more urban centers along the way.

"The road is not necessary to meet the objectives of economic development," Sinclair, of the University of British Columbia in Canada, wrote in a recent paper he distributed to conservationists and journalists.

"A southern route would have none of the environmental problems and a much greater economic benefit than the present proposal."

Still, it's important to acknowledge the government's desire for economic growth, said wildlife filmmaker Dereck Joubert, a National Geographic Society explorer-in-residence who has worked in the Serengeti for years. (The National Geographic Society owns National Geographic News.)

If the road project is going to go ahead, Joubert said, conservationists should work with the government to mitigate the road's impact, since even bigger threats to the Serengeti could come from construction workers and poachers.

"What happens is that construction workers go in there and set up camp. They start poaching and get scared by lions and kill lions. It will be the predators that get hammered first," Joubert said. (See "Lions, Hyena Killed With Poisoned Meat.")