ColorMePhD, a free coloring book series created by UC Berkeley alumna Julie Rorrer, showcases the work of ITS Berkeley alumna in Volume 2: Women in STEM. Professor Bills is celebrated for her research on equitable transportation accessibility, and she is shown with the building blocks that make up her model for analysis.
Dr. Bills's research focuses on microtransit, a form of transit that is digitally-enabled and operated on demand. In contrast to traditional fixed route transit, microtransit is more flexible and reliable. However, microtransit often costs more that fixed route transit, leaving planners and officials wondering whether it effectively serves the needs of disabled, elderly, and low-income travelers.
According to a study Dr. Bills conducted in Detroit, Michigan, microtransit led to larger accessibility gains for lower income communities and transit-dependent households. Overall, the microtransit services were likely to help reduce 
the gap in accessibility between vulnerable and more affluent travelers in Metro Detroit.
To learn more about Dr. Bills's work and that of other amazing scientists, visit ColorMePhD.