Rio’s sprawling shanty towns are home to about a fifth of the city’s population, yet many favelas do not appear on digital maps which adds to the sense of neglect felt by communities living there, activists say.

Internet companies have long had difficulty navigating unmarked streets and collecting data on informally-built neighborhoods covering the hillsides around Rio.

But for the last couple of years, local activists have teamed up with Google in an effort to map the city’s slums to “break the barrier of digital exclusion.”

“People say they feel like they’re part of the city when their communities are included on the map,” said Ronan Ramos Jr., coordinator of the On the Map project with the Brazilian charity group Afro-Reggae.

“With this mapping, people (in other parts of Rio) can see the good things going on in the favelas,” Ramos Jr. told the Thomson Reuters Foundation in an interview.

He hopes that some of the 500,000 foreign visitors that are expected to descend on Rio for the Olympics next month will use the map to search for attractions or businesses in the favelas.

“The Olympics is no doubt a good time for the project, and for small, medium and large businesses,” he said.

Small business owners in the slums running everything from restaurants to Harley Davidson motorcycle repair shops have taken advantage of the map to promote themselves to customers who otherwise would be unable to find them, Ramos Jr. said.

Mapping a favela, where many residents lack formal title deeds to their homes and businesses, takes about three months.

“The lack of legal ownership papers is a main cause of the disorganization in the favelas,” Ramos Jr. said.

The group of mappers first approaches the local authorities in an area to get approval for mapping it.

If the community backs the project, young residents receive training and are sent out into the neighborhood to take pictures and record information about the location of streets, alleyways, businesses and interest points.

Once data is collected from the field it is sent to Google which puts a map together and then posts it online.

Since the project launched the group has created maps for 25 of more than 1,000 favelas in Rio de Janeiro, Ramos Jr. said.

The Olympics however have not been welcomed by all Brazilians with more than 20,000 families re-located since 2009 in the state of Rio de Janeiro alone, many of them to make way for Olympic projects.

(Reporting By Chris Arsenault; Editing by Katie Nguyen. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women’s rights, trafficking and climate change. Visit news.trust.org)