Final answer:
The indication of an automatic signal with both the green and yellow lenses illuminated is considered a more cautious and restrictive indication.
Step-by-step explanation:
The indication of an automatic signal which has been both the green and yellow lenses illuminates is considered as the most restrictive indication that can be given by the signal. This means that when both the green and yellow lenses are illuminated, it indicates a more cautious approach and potentially a warning for the driver.
For example, in traffic signals, the green lens usually indicates that it is safe to proceed, while the yellow lens indicates that the signal is about to change to red. When both lenses are illuminated, it means that the signal is in a transitional phase and the driver should proceed with caution.