Document ID: chunk:federal_register_of_legislation:F2023L01321:front:0:p5
Version: federal_register_of_legislation:F2023L01321
Segment Type: other
Provision Reference: 
Character Range: 15252–18107

heavy vehicles and bicycles can be significant due to misunderstanding of the situation be the vehicle operators. In some cases, the increase can occur so suddenly that a high-intensive warning, intended to generate a driver reaction to the situation after an appropriate reaction time, cannot be activated early enough. In general, driver reactions to any information (high or low threshold / warning or information) can be expected only after a reaction time. This response time is much longer than the time required to avoid the accident in many situations – the accident cannot be avoided despite the warning.
0.3. High-intensity warnings during a driving situation are only justified if the probability for an accident is high – otherwise vehicle drivers tend to ignore the system alerts. A (low threshold) informational assistance system, however, can be activated sufficiently early enough, as it helps the driver rather than annoys. It is assumed to be possible to design an human-machine-interface for blind spot assistance systems in a way that it does not annoy drivers when the information is not needed, for instance by selecting the location of a signal outside of the primary focus area of drivers when looking straight ahead, but in an area that is visible when the gaze is slightly turned towards the planned driving direction. A favourable location that fulfils these requirements is a location approximately 40° off the right from an axis in direction of the vehicle centreline and through the driver's eyepoint.
0.4. Therefore the UN Regulation asks for an early activation of an information signal in case a bicycle might be entering a critical area on the passenger side of the vehicle, if the heavy vehicle would initiate a turn towards the bicycle, including situations where a counter-turn (away from the bicycle) is necessary to negotiate the turn. This informational assistance signal shall only be deactivated automatically in case of system failure or contamination of the sensors; a manual deactivation shall not be possible.
0.5. Additionally, the UN Regulation asks for a different signal which shall be given when the collision becomes unavoidable, e.g. when a clear turn on the steering wheel or the operation of the turn indicators is detected. This additional warning signal may be deactivated manually or automatically; it shall be deactivated together with the information signal in case of failure or sensor contamination.
0.6. The UN Regulation defines a test procedure which does not require actual turning manoeuvres; this is acceptable since the information signal needs to be present sufficiently early anyway. Experimental data shows that some turn manoeuvres of heavy vehicles, especially when turning into a narrow street, require a counter-turn that starts approximately 15 m before entering that street, so