DOI: 10.13020/gd60-km49
title: Access Across America: Transit 2024 Data

description: These data were created as part of a study that examines the accessibility to jobs by transit across the United States. It is a detailed evaluation of access to jobs by transit during the AM peak hour, and it allows for a direct comparison of the transit accessibility performance of America's metropolitan areas. These data are part of a longitudinal study. Transit data for additional years can be found in the Accessibility Observatory Data collection: https://hdl.handle.net/11299/200592
description: This dataset provides a summary of the worker-weighted access by different census geography levels and travel times for each state. The worker-weighted access here represents the average number of jobs a person can reach from a specific census area within a given travel time threshold, using a combination of walk/roll plus public transit. The travel time threshold are in integer minutes, at five-minute intervals from 5 min to 60 min (1 hour).

For transit accessibility, the match between schedule and departure time greatly influences what is reachable. We use available published transit schedules for a given travel day, and calculate access based on the 15th percentile travel time between origin and destination across each minute from 7am to 9am. This removes some of the variation due to mismatch of departure, and represents a fast but regularly observed travel time. Transit access travel times include walking or rolling to and from stops, as well as waiting. Where no applicable transit service is available, the accessibility metric represents jobs available by walking or rolling.

Census levels included in this dataset are: Block, Block Group, Census Tract, County, and State. The file-naming system for the data files is [state]_[statecode]_[mode]_[census_level]_[year].csv: These files contain the census level data by mode, year. 

**Important Note: Due to its large size, the 'Block' level data file should not be opened outside of a person's coding platform. Attempting to open this file in Excel or a similar spreadsheet program would cut off a significant amount of data points.**

Data fields included in the data are: 1. mode: the type of travel modes, one of auto, bike, or transit; 2. year: National Accessibility Evaluation data year, the year for which this dataset is relevant; 3. parent_area: the ID of the containing geography within which the data averages are calculated; 4. summary_level: the level of geography at which averages are calculated - one of state, county, census tract, block group, or block; 5. geoid: the ID of the particular census geography for which the data averages are calculated; 6. threshold: the travel time threshold in minutes, ranging from 5 to 60 minutes; 7. weighted_average: the average number of jobs a person can reach from a given census area within the travel time threshold for a specific mode.

The LODES dataset used to calculate jobs in this data does not include job location data from the states of Alaska, or Mississippi. Therefore these states are not included in this data archive. Additionally, the state of Michigan did not share jobs location data with the Census in 2022. Job accessibility data for Michigan represents 2021 LODES data. See documentation at https://lehd.ces.census.gov/doc/help/onthemap/LODESTechDoc.pdf