While the government of Tanzania is appealing a ruling against the proposed highway across the Serengeti, alternatives have been suggested, including an underground tunnel.
The idea for the underground tunnel below the Serengeti National Park was put forward by the Mazingira Network Tanzania (Manet), a network of organisations dealing with environmental issues. 

Frank Luvanda, Manet Secretary, says Manet understands and supports the right of every district in Tanzania to be connected to the Tanzanian road network. He adds, however, that Manet has suggested that the government should consider connecting Mugumu town (Serengeti District) to Tabora B with a normal tarmac road, and then from Tabora B to Kleins Gate (Ngorongoro District) through an underground tunnel to  ensure that there is sustainable management and conservation of the Serengeti ecosystem and wildebeest migration.
Luvanda told Tourism Update that Manet would largely favour the option of the Southern Eyasi Route over any other alternative. “If Manet were to choose between the underground tunnel versus the Southern Eyasi Route, we would choose the Southern Eyasi Route. The only thing that has made us suggest the underground tunnel is the fact that the government of Tanzania has shown interest and is still clinging to [plans to] build the highway across Serengeti National Park.”
Luvanda further also cautions the government: “Manet requests the government to respect its technical experts’ opinions rather than only listening to self-serving politicians before embarking on any huge investment scheme that ultimately may bring more damage than prosperity to the country.”