ECE Regulation No. 121 establishes uniform conditions for the approval of vehicles with respect to the location, identification, and operation of controls, displays, and indicators. The purpose of this regulation is to ensure that these components are designed and positioned in a way that makes them easily recognizable, intuitive, and user-friendly for the driver. Implementing this standard plays a key role in enhancing vehicle safety and driver comfort.

This regulation defines the technical standards required for the design, construction, and operation of in-vehicle controls, indicators, and symbols. The goal of these standards is to ensure that controls are easily identifiable and usable under various driving conditions, and that indicators provide clear and unambiguous information to the driver. The regulation also emphasizes that these components must undergo various tests to verify their safety and functional performance.

The test procedures under this regulation are precisely defined to ensure that vehicles comply with the specified requirements. These tests include the assessment of the visibility and recognizability of indicators and symbols, the usability of controls under various driving conditions, and the ergonomic layout of the vehicle’s interior. Manufacturers are required to conduct these tests to demonstrate that their vehicles meet the applicable standards. The regulation also includes requirements related to the durability and reliability of these components, ensuring that they perform properly throughout the vehicle’s service life.

TAT Laboratory is authorized in Iran to perform tests and issue certifications for compliance with ECE Regulation No. 121. This includes conducting all necessary evaluations to ensure that vehicle controls, indicators, and symbols meet the specified standards for safety, functionality, and usability. TAT Laboratory utilizes advanced equipment and testing methodologies to carry out these assessments accurately and efficiently. Through these efforts, the laboratory contributes to improving vehicle safety in Iran by ensuring that vehicles are equipped with user-friendly controls and displays that provide clear information to drivers—ultimately promoting safer driving conditions.

​