Inquiry Regarding Regional Transit Data for Master's Thesis Research

I am a graduate student at California State University, Chico, currently in the final stages of completing my master’s Thesis.

My research focuses on assessing the impact of public transportation accessibility on labor participation, specifically in the cities of Sacramento, Denver, and Portland. I have successfully obtained data for my dependent variable, which is the percentage of the population engaged in full-time employment (averaging more than 40 hours a week) from the U.S. Census Bureau. However, I am encountering challenges in acquiring data for my independent variable, which is the percentage of regional jobs accessible by public transit.

To facilitate my research, In addition to reaching out to the three municipalities, I am reaching out to your esteemed agency with a few inquiries as well because the EPA produced the smart location map. While vital to my research, it does not produce the cross-sectional data I need to track labor participation and percentage of reginal jobs accessible by transit since it is only showing one year. They lead me to the GTFS-Realtime group. I need multiple years. So if possible, can anyone help with:

-              I am seeking data on the percentage of regional jobs accessible by public transit for the years spanning from 2000 to the present for these three cities. Any available information during this timeframe would significantly contribute to the depth of my analysis.

-              Additionally, I am interested in gathering supplementary data related to city's transportation system that could further support my hypothesis. This may include average commute times, transit service frequency, the percentage of individuals leaving their homes after 4 PM, and any other relevant statistics or insights related to public transit in your region.

Thank you to anyone who helps!!