Safety standards for public buildings are set by the Occupational Safety & Health Administration (OSHA). Included in the standards are the design of pedestrian passageways.
Twenty-Eight Inches Minimum
Twenty-eight inches is the minimum width for any walkway leading to an exit. The door must at least equal the passageway width if there is only one passageway.
Expected Use
If a large number of people is expected to use the passageway, the width must be more than 28 inches.
Decresing Width
As a passageway approaches an exit, it may not decrease in width.
Dual Use
A passageway that has dual use with machinery such as fork-lifts must provide clearance of at least three feet wider than the largest equipment, or a minimum of four feet.