WHERE THE CONCHOS GO: HOW STUDENTS, WOMEN, AND BLIND RESIDENTS RECHARTED SANTIAGO
PROJECT PARTICIPANTS INTERVIEWED:
SARAH WILLIAMS, Director of the Civic Data Design Lab at MIT
NATALIA VIDIGAL COACHMAN, lead designer, physical map production
PATRICIO ZAMBRANO-BARRAGÁN, Urban Development Specialist
CÈSAR BALLAST, student mapper, processing, audit and focus groups.
MIGUEL MOYA, student mapper, data processing, audit and focus groups
Written response by ALDO CEREZO
SARAH WILLIAMS, Director of the Civic Data Design Lab at MIT
NATALIA VIDIGAL COACHMAN, lead designer, physical map production
PATRICIO ZAMBRANO-BARRAGÁN, Urban Development Specialist
CÈSAR BALLAST, student mapper, processing, audit and focus groups.
MIGUEL MOYA, student mapper, data processing, audit and focus groups
Written response by ALDO CEREZO
The effort to map public transportation in Santiago de los Caballeros began with a single question: Could a proposed road be re-routed to protect the city’s watershed? The Inter-American Development Bank (IDB), a supporter of a plan to construct a new urban park along the Yaque del Norte River, needed better transportation data in order to evaluate alternative routes for a controversial highway expansion. Officials in Santiago insisted the road couldn’t be touched because too many people relied on it, but there were no numbers to prove it.
A plan to map the city’s sprawling, unregulated transit system so as to better inform infrastructure design came together. But as the work began, something changed, and what began as a technical task—to collect GPS data—became a deeply civic one. By engaging local students to perform the field research, the project gave them the tools, skills, and recognition to become active stewards of their own city.
“We didn’t want this to just be a study for consultants,” explains Patricio Zambrano, the urban development specialist at the IDB who helped launch the project. “We wanted it to be something the whole city could use.”
And in the end, that’s exactly what it became. The students charted much more than routes. They charted who feels safe, who is seen, and who gets to belong.
THE RHYTHM OF SANTIAGO
Set in the foothills of the Cibao Valley, Santiago de los Caballeros isn’t built on rigid order. The pulse of bachata from colmados and the buzz of motoconchos weaving through midday traffic, set to the slow build of a tropical afternoon heat, dictate its pace. It is a place of improvisation and flow.
The city’s transportation system reflects that spirit.
The vast majority of the city’s 800,000 residents travel by concho—a shared sedan that operates like a low-cost taxi. There are no signs or timetables. Routes are passed down through familiarity and word of mouth. People flag the cars from curbs, climb in alongside strangers, and jump out wherever it makes sense.
“It’s not structured—it’s social,” says Miguel Moya, a civil engineering student who had relied on conchos since childhood. “There’s music, conversation, street noise. It reflects the energy of the city.”
But all of this local movement logic was invisible to planners. “The city had no map, no baseline. We were starting from scratch,” Patricio recalls.
So the IDB partnered with the Civic Data Design Lab at the Massachusetts Institute of Technology (MIT), which had been working across Latin America and Africa to create open-source mapping tools. The lab’s director, Sarah Williams, tapped MIT graduate student Natalia Vidigal Coachman to lead the on-the-ground effort.
STUDENTS TAKE THE LEAD
Natalia had never been to the Dominican Republic before. She arrived in Santiago with a fellowship, a suitcase, and a plan: coordinate a grassroots “mapathon” to chart the city’s informal transit routes. “The next day, I was leading a training,” Natalia remembers. “We had 30 students from universities in Santiago and Santo Domingo, most of whom had never mapped anything before.”
They split into teams, equipped with GPS apps like Mapillary and MapMap, and spent four long days riding conchos across every corner of the city. The cars had no fixed stops. Sometimes they turned back early. Sometimes they detoured off-route. Students had to ask drivers directly where they were going and why.
“They’d ask us, ‘Why do you want to know?’” says César Ballast, one of the student mappers. “And when we told them it was to help the whole city, most were really supportive.”
Despite the complexity of the task, the team mapped 54 routes—one of the fastest and most complete informal transit mappings ever completed.
“People said it couldn’t be done,” Patricio reports, “But the students proved otherwise.”
A plan to map the city’s sprawling, unregulated transit system so as to better inform infrastructure design came together. But as the work began, something changed, and what began as a technical task—to collect GPS data—became a deeply civic one. By engaging local students to perform the field research, the project gave them the tools, skills, and recognition to become active stewards of their own city.
“We didn’t want this to just be a study for consultants,” explains Patricio Zambrano, the urban development specialist at the IDB who helped launch the project. “We wanted it to be something the whole city could use.”
And in the end, that’s exactly what it became. The students charted much more than routes. They charted who feels safe, who is seen, and who gets to belong.
THE RHYTHM OF SANTIAGO
Set in the foothills of the Cibao Valley, Santiago de los Caballeros isn’t built on rigid order. The pulse of bachata from colmados and the buzz of motoconchos weaving through midday traffic, set to the slow build of a tropical afternoon heat, dictate its pace. It is a place of improvisation and flow.
The city’s transportation system reflects that spirit.
The vast majority of the city’s 800,000 residents travel by concho—a shared sedan that operates like a low-cost taxi. There are no signs or timetables. Routes are passed down through familiarity and word of mouth. People flag the cars from curbs, climb in alongside strangers, and jump out wherever it makes sense.
“It’s not structured—it’s social,” says Miguel Moya, a civil engineering student who had relied on conchos since childhood. “There’s music, conversation, street noise. It reflects the energy of the city.”
But all of this local movement logic was invisible to planners. “The city had no map, no baseline. We were starting from scratch,” Patricio recalls.
So the IDB partnered with the Civic Data Design Lab at the Massachusetts Institute of Technology (MIT), which had been working across Latin America and Africa to create open-source mapping tools. The lab’s director, Sarah Williams, tapped MIT graduate student Natalia Vidigal Coachman to lead the on-the-ground effort.
STUDENTS TAKE THE LEAD
Natalia had never been to the Dominican Republic before. She arrived in Santiago with a fellowship, a suitcase, and a plan: coordinate a grassroots “mapathon” to chart the city’s informal transit routes. “The next day, I was leading a training,” Natalia remembers. “We had 30 students from universities in Santiago and Santo Domingo, most of whom had never mapped anything before.”
They split into teams, equipped with GPS apps like Mapillary and MapMap, and spent four long days riding conchos across every corner of the city. The cars had no fixed stops. Sometimes they turned back early. Sometimes they detoured off-route. Students had to ask drivers directly where they were going and why.
“They’d ask us, ‘Why do you want to know?’” says César Ballast, one of the student mappers. “And when we told them it was to help the whole city, most were really supportive.”
Despite the complexity of the task, the team mapped 54 routes—one of the fastest and most complete informal transit mappings ever completed.
“People said it couldn’t be done,” Patricio reports, “But the students proved otherwise.”
MAPPING ACCESS, NOT JUST MOBILITY
The mapathon didn’t stop at transit routes. From the start, the team asked: who has access to the city? Who feels safe moving through it?
After completing the initial mapping, the same students conducted a second phase: a qualitative mapping of accessibility, security, and gender. They used three methods: walking focus groups with an association of blind residents, community leaders, and a women’s organization, recording georeferenced audio with open-source apps like Mapillary and OsmAnd; an audit of 3,205 public space images collected along eight concho routes; and an online survey on concho service quality and rider profiles.
“It was a unique kind of mapping,” Natalia says. “We were documenting how people experience the city.”
Using photographs and annotations, the team created a visual, tactile layer of accessibility data. These were added directly onto the transit map; a guide for blind users, yes, but also a tool the city could use to make improvements.
In parallel, another team worked with a women’s organization to conduct what they called a “fear mapping.” Participants highlighted the places where they felt unsafe, due to poor lighting, loitering, or harassment.
“It wasn’t just about where you could go,” Natalia said. “It was about where you wanted to go.”
These layers—of gender, disability, and lived experience—transformed the project from a map of movement into a map of belonging.
“That kind of data is precious,” notes César. “No one else collects it, but it’s what matters most.”
SHARING THE MAP, AND THE POWER
After the data was processed and formatted by mobility expert Aldo Cerezo Cázares into the open GTFS standard, the results were uploaded to Google Maps, making Santiago the first city in the Caribbean with its informal transport system mapped online.
But the physical map was just as meaningful. Natalia and the team created a large-format print version, which they presented at a public ceremony attended by the mayor. There, every student received a certificate recognizing their contribution.
“To hold the map in my hands and see my name on that certificate was one of the proudest moments of my life,” Natalia recalls.
“This was a map that taught people how to move through the city,” Miguel notes, adding, “It also showed us that we could shape the city, too.”
Natalia, overwhelmed by the complexity of creating the map by hand in Illustrator and AutoCAD, eventually wrote a tutorial to guide other urban cartographers through the process.
“There was no magic software,” she says, laughing. “We figured it out together. And now others can do the same.”
A LIVING LEGACY
The highway hasn’t been built—yet. The debate is ongoing. But now, those conversations happen with data in hand, and with a clearer understanding of how people actually move through the city.
More importantly, the project left behind something lasting: a new model for what data can be. A tool of inclusion, a form of recognition, a guide for those long left out of the city’s plans: it can be all of these, even at the same time.
“Before, people thought the conchos weren’t part of the system,” says César. “Now they’re on the map. Now they count.”
In Santiago, data didn’t just support a project––it became a movement.
The mapathon didn’t stop at transit routes. From the start, the team asked: who has access to the city? Who feels safe moving through it?
After completing the initial mapping, the same students conducted a second phase: a qualitative mapping of accessibility, security, and gender. They used three methods: walking focus groups with an association of blind residents, community leaders, and a women’s organization, recording georeferenced audio with open-source apps like Mapillary and OsmAnd; an audit of 3,205 public space images collected along eight concho routes; and an online survey on concho service quality and rider profiles.
“It was a unique kind of mapping,” Natalia says. “We were documenting how people experience the city.”
Using photographs and annotations, the team created a visual, tactile layer of accessibility data. These were added directly onto the transit map; a guide for blind users, yes, but also a tool the city could use to make improvements.
In parallel, another team worked with a women’s organization to conduct what they called a “fear mapping.” Participants highlighted the places where they felt unsafe, due to poor lighting, loitering, or harassment.
“It wasn’t just about where you could go,” Natalia said. “It was about where you wanted to go.”
These layers—of gender, disability, and lived experience—transformed the project from a map of movement into a map of belonging.
“That kind of data is precious,” notes César. “No one else collects it, but it’s what matters most.”
SHARING THE MAP, AND THE POWER
After the data was processed and formatted by mobility expert Aldo Cerezo Cázares into the open GTFS standard, the results were uploaded to Google Maps, making Santiago the first city in the Caribbean with its informal transport system mapped online.
But the physical map was just as meaningful. Natalia and the team created a large-format print version, which they presented at a public ceremony attended by the mayor. There, every student received a certificate recognizing their contribution.
“To hold the map in my hands and see my name on that certificate was one of the proudest moments of my life,” Natalia recalls.
“This was a map that taught people how to move through the city,” Miguel notes, adding, “It also showed us that we could shape the city, too.”
Natalia, overwhelmed by the complexity of creating the map by hand in Illustrator and AutoCAD, eventually wrote a tutorial to guide other urban cartographers through the process.
“There was no magic software,” she says, laughing. “We figured it out together. And now others can do the same.”
A LIVING LEGACY
The highway hasn’t been built—yet. The debate is ongoing. But now, those conversations happen with data in hand, and with a clearer understanding of how people actually move through the city.
More importantly, the project left behind something lasting: a new model for what data can be. A tool of inclusion, a form of recognition, a guide for those long left out of the city’s plans: it can be all of these, even at the same time.
“Before, people thought the conchos weren’t part of the system,” says César. “Now they’re on the map. Now they count.”
In Santiago, data didn’t just support a project––it became a movement.