While women have made extraordinary progress since the first International Women’s Day more than a century ago, a number of barriers still stand in the way of equality for women worldwide.

In 2016, violence against women remains one of the biggest challenges to achieving inclusive development globally. One in every three women experience some form of physical or sexual violence in their lifetime. From India to Germany, the United Kingdom to the United States, women are subject to sexual harassment, sexual assault, rape, and femicide in their homes, in public spaces, and also in and around public transportation.

Inclusive, accessible public transportation allows people to take advantage of economic and social opportunities. When women feel uncomfortable or unsafe taking public transportation, they’re less likely to travel at all, which limits their access to education, higher-paying work, social networks, and more.

And when women don’t have access to safe public transportation, whole communities are affected. Accessible and inclusive transportation is key to making cities resilient.

Sustainable development is only possible through mainstreaming gender equality. Making transportation accessible to girls and women requires incorporating gender perspectives into city planning, transportation projects, and the provision of services. Transportation systems cannot be inclusive if city authorities and planners do not account for gender-specific challenges women and girls face in public spaces.

The United Nations has placed a high priority on making sure that men and women are able to experience equal access to public transport, and the World Bank’s recent Transforming Transportation Conference helped illustrate how gender equality in transportation is central to sustainable development.

A new partnership between the Urban Institute, Nigeria’s Center for Public Policy Alternatives, Kenya’s Egerton University, and Pakistan’s Leadership for Environment and Development will address how gender equality fits into the global conversation about sustainable development, and explore how the prospects for women’s empowerment are shaped by a wide range of factors, from evolving rights and cultural norms to urban growth and market integration.

One study will explore how patterns of urban change and growth and the quality of urban transport infrastructure affect women’s safety, economic productivity, and economic choices in megacities of Pakistan and Nigeria.

Understanding what conditions around public transportation make women feel unsafe will be extremely useful in helping city planners and officials more efficiently use limited government resources to make transportation accessible and safe for women—and ultimately, help women live better lives.