He and a small team just championed the launch of a new wheelchair friendly transit feature on Google Maps.

When he returned to work, he focused on accessibility issues within the company.

Over eight years ago, a rotted tree branch crashed down on Sasha Blair-Goldensohn as he walked through Central Park, putting him in a temporary coma and partially paralyzing his lower body. Blair-Goldensohn returned to work less than two years later, equipped with both a new wheelchair and a fresh perspective on how his employer — Google — designs products to help people with disabilities. Google has long had an 'accessibility team' that strives to make digital services like search and Gmail usable for those with limited vision, hearing or mobility. But as Blair-Goldensohn struggled to navigate the New York City subway system, with its paltry number of elevators and limited service updates, he realized there was so much more Google could do to assist people in the physical world. This week, he's celebrating a major milestone: Google Maps just introduced "wheelchair accessible" routes in transit navigation in New York, London, Tokyo, Mexico City, Boston, and Sydney. Maps users in those cities will be able to search for wheelchair-friendly ways to get around.

Blair-Goldensohn expects more locations to join. A day after the product launched, a co-worker told him that the transit authority in an Argentine city had expressed interest. "Just having it out in the world is the best way to move the product forward, both in terms of getting feedback from users, from transit authorities and even from within Google," Blair-Goldensohn told CNBC. The project took off about two years ago, when Blair-Goldensohn and two other employees, Rio Akasaka and Diana Hu, took it on as a "20 percent project," a Google initiative that employees pursue outside of their formal workload. "There's a major underserved population and [Maps] is a major opportunity," Blair-Goldensohn said. "But, like with everything, you have to be your own advocate. It took a while to find allies within Google, within Google Maps." The group made a "proof of concept," and then got the go-ahead to move forward. Last year, Google also introduced new accessibility details to Maps and asked users to add information to as many places as possible, with the aim of helping the 65 million people worldwide who need a wheelchair as well as people who are pushing strollers, using crutches, or lugging suitcases.