Writing in the journal Nature, the 27 scientists said the road would curtail wildebeest migration, with knock-on effects on the area's ecosystem.

BBC: Scientists urge rethink of Serengeti road plans

Mwanga Moto in the Serengeti is mobile, moving several times a year to follow the wildebeest migration, while Palahala in the virtually untouristed, hipporich Katavi National Park in western Tanzania is permanent but low impact.

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For seven hours every Sunday, the city closes more than 100km of roads to motor vehicles, and a wildebeest-worthy migration of bikes and pedestrians takes over the city.

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The migration of the wildebeest was the "largest remaining migratory system on Earth", they said.

BBC: Scientists urge rethink of Serengeti road plans

The large numbers of herd animals -- wildebeest, zebra, antelope -- and the drama of the migration attract many visitors to Kenya and Tanzania -- but in places like the Ngorongoro Crater you are likely to see many other vehicles during a game drive.

CNN: , for CNN Travel