It was hard to imagine how much added weight the train had taken on since we left Dar es Salaam, or whether each of the cabins had begun, like ours, to resemble the produce section of Whole Foods.

Onboard were traders and market women carrying goods from Dar es Salaam deep into the interior - some continuing on to landlocked Burundi and the eastern Congo.

A former employee of the Tanzanian Railways Corp., he had done the end-to-end journey from Dar es Salaam to his home in Kigoma more times than he could remember.

The first three platforms were on urbanization, green growth, and ICT for open development, which is aiding the Dar es Salaam mapping effort.

In Dar es Salaam, urban planning students from local Ardhi University are geocoding with assistance from community volunteers.