During the latter half of the 20th century, traffic engineering was based on the principles of “forgiving design“. Under this approach, streets were widened and curbside features were removed in the name of safety and flow. But this didn’t work, and as Better Cities & Towns writes, not only did it never work, it was based on conjecture. There is hope however. A data-driven approach shows that narrower streets, bordered by previously banned features, like trees, can reduce crashes while also creating more people-friendly environments.