Project Sidewalk is an exciting research initiative happening right here at the University of Maryland!
Project Sidewalk allows users to virtually explore areas to assess accessibility needs in an area. It combines crowdsourcing with technologies such as Google Street View to conduct a thorough investigation of infrastructure in DC. According to their website, they have already mapped over 450 miles of DC! This information is transformed into more effective accessibility mapping and better city planning efforts.
If you are interested in getting involved, visit https://sidewalk.umiacs.umd.edu/