Interpretation ID: nht80-4.27

DATE: 12/09/80

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Wisconsin State Patrol

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your October 28, 1980, letter asking whether Standard No. 217, Bus Window Retention and Release, requires that there be an aisle to provide access to a side exit. The answer to your question is no.

Standard No. 217 states that side emergency exits on school buses must have an opening of 45 by 24 inches. The standard further states that a vertical transverse plane tangent to the rear most point of a seat back shall pass through the forward edge of the emergency exit. These requirements mean only that the size of the opening must be 45 by 24 inches, and that the opening must be located in a specific place with reference to the seat back.

The Federal government does not require an aisle or other access to a side emergency exit. Although some seats may partially block a side emergency exit, it can still be used for emergency exit purposes and is supplementary to a rear emergency exit. The agency adopted this approach to side emergency exits as a balance between the desire for additional exits in school buses and the need to maintain the fullest possible seating in school buses as well as the proper seat spacing.

A State is permitted to require an aisle leading to the side exit if the State determines that this is an area that it would like to regulate. Such a regulation would not be preempted, because the Federal government does not regulate the placement of aisles in buses. However, the required seat spacing would need to be retained. This means that the seat behind the aisle leading to a side emergency exit would need to have a restraining barrier placed in front of it. The net effect of the aisle and the restraining barrier could be a substantial loss of seating capacity.

SINCERELY,

State of Wisconsin / DEPARTMENT OF TRANSPORTATION

DIVISION OF ENFORCEMENT AND INSPECTION

October 28, 1980

Roy Shannon U.S. Department of Transportation N. H. T. S. A.

Dear Mr. Shannon:

I am writing to you reference our conversation about the 1980 Thomas School Bus Body with the Side Emergency Door. I have enclosed pictures and a sketch with measurements.

In further inspection of this Emergency Door, I find it quite difficult to exit, especially if you are sitting in the seat located in the door opening. (The State of Wisconsin Rule MVD 17 requires a 12 inch aisle to the Emergency Door zone.)

I am interested in the application of your Standard No. 217, Section S5.4.2.1 (b) which reads: In the case of a side emergency door, an opening at least 45 inches high and 24 inches wide. A vertical transverse plane tangent to the rearmost point of a seatback shall pass through the forward edge of a side emergency door. Does this mean that there must be an opening with access or does it mean that there must only be an opening in the side of the bus that size? The seat blocks this emergency door opening so that there is not an opening 45 inches by 24 inches.

Thank you for your interest and attention and if I can be of further assistance, please contact me.

Ronald H. Wonders Inspector III

(Graphics omitted)

(Graphics omitted)