RP 428B - Guidelines For Vision Devices: Introduction

The capability to see all around a vehicle is a fundamental requirement for any driver. It is extremely important for the driver to see other vehicles or obstacles-either by direct vision (unaided vision as viewed through the vehicle windshield or side windows) or indirect vision (through the use of supplemental vision devices, such as mirrors or cameras).

This RP establishes vision requirements for various driving maneuvers. The RP is based on input from fleet managers and drivers, as well as interaction with the Society of Automotive Engineers' (SAE) Visibility Task Force.

This RP defines:

• A procedure to tabulate a "vision score" for the zones specified in SAE J1750.
• Targets that must be visible to meet TMC minimum acceptance criteria.
• An interim method to assess clarity of view (COV) until an industry-wide standard evaluation method is developed.

The terms "See", "Vision", "Visible", and "Visibility" are used throughout this RP and these terms are intended to include:

• Direct Vision  - Objects visible with the unaided human eye.
• Indirect Vision  - Objects visible with a vision device (usually, but not limited to, mirrors).
• Supplemental  - Objects whose presence is communicated to the driver through a non-traditional vision device (e.g., camera and monitor) or audible warning.