Improving Road Safety in Nairobi

by Holly Krambeck
Waze Transport

“Data Partnership brings domain expertise. Google brings data expertise. Together we impact real world problems.”

–Google’s Bailey-Galvis noted at a Data Partnership event in early February 2019

Waze Data Day Video from Data Partnership on Vimeo.


Kenya has one of the highest estimated crash fatality rates worldwide but is challenged to address the problem without adequate data.


Real-time access to Waze Connected Citizens program data helped identify patterns of traffic incidents and congestion.


A new method to better inform road safety interventions in Nairobi and similarly data-scarce environments.

The government of Kenya – from policy designers and implementers to regulators and enforcers – face a challenge: they know road crashes are a serious issue, particularly in the capital Nairobi. However, details of where and when such crashes occur are unavailable to city officials.

How can cities design policies that save time, money – and lives – without adequate data and monitoring of a problem?

In 2017, a team consisting of Lupe Bedoya, Arianna Legovini, Sveta Milusheva, and Rob Marty of the Development Impact Evaluation Group (DIME) at the World Bank, alongside Sarah Williams of the Massachusetts Institute of Technology and Elizabeth Resor of University of California, Berkeley, sought to map crashes in order to better inform public infrastructure development. However, when an estimated 75% of the crashes are unreported, where to start such evaluation is a significant part of the challenge.

The Development Data Partnership seeks to address the mismatch between the demand and supply of proprietary data for public good. By facilitating a data sharing agreement with Waze, the Partnership made it easy for the Nairobi team to access Waze API content for all 175 km of the city’s road network. With near real-time data of user-reported incidents, the team could see patterns of accident hotspots and congestion emerge.

For the past year, the team has analyzed Waze data alongside Twitter and police reports, as well as environmental data from AccuWeather and Code for Africa. With these six data streams, Kenyan policymakers can see a more complete view of road safety risk patterns. Waze data is a building block of a data system that can improve the safety of Nairobi’s 3 million citizens, as well as other cities where administrative data is scarce.

Read more