# 2015 Auto and Transit Accessibility Data

This archive contains auto and transit job accessibility data for the year 2015, produced as part of the National Accessibility Evaluation project.

## File Format

The data are stored in a comma-separated values (CSV) format with ASCII encoding. This format can be read by all major spreadsheet software (including Excel), GIS software (including ArcGIS), and can be imported into most database types. However, note that some software limit the *size* of file that can be opened -- for example, Excel limits files to 1,048,576 rows, which will prevent it from opening many of the accessibility data files.

The specific data contents of each file are indicated by the filenames, which are described below

## Auto Data Files

Auto data files have names following the format:

[area]_au_[year]_[departure time].csv

    - area: indicates the geographic area covered by this dataset
    - year: indicates the year for which this dataset is relevant
    - departure time: indicates the departure time used for the accessibility data in this dataset (in 24-hour format)

For example, the file...

    AR_au_2015_1700.csv

...contains data covering the state of Arkansas, for 2015, with a departure time of 5:00pm.

## Transit Data Files

Transit data files have names following the format:

[area]_tr_[year]_[start time]-[end time].cscv

    - area: indicates the geographic area covered by this dataset
    - year: indicates the year for which this dataset is relevant
    - start time: indicates the first departure time included in transit accessibility calculations
    - end time: indicates the last departure time included in transit accessibility calculations

Note that transit accessibility calculations are performed for a range of departure times and then averaged.

For example, the file...

    AR_tr_2015_0700-0859.csv

...contains data covering the state of Arkansas, for 2015, averaged over departure times from 7:00am to 8:59am.

