Official White House Photo by Pete Souza

Here’s a particularly powerful photo of President Obama sitting on the bus in which civil rights activist Rosa Parks famously refused to give up her seat. It’s hard to imagine President Obama would be where he is today without the courage and determination of Parks and the thousands of men and women like her who fought against racial injustice.

To submit a photo for the Art of Transit, post it to Metro’s Flickr group, email it to sourcemetro@gmail.com or Tweet it to @metrolosangeles with an #artoftransit hashtag. Many of the photos we’ve featured can be seen in these galleries on Flickr.