What position must the comb segment teeth be in relation to the upper surface of the treadway?

The correct answer is that the comb segment teeth must be below the upper surface of the treadway. This is essential for ensuring a safe and smooth transition for passengers getting on and off the elevator. Having the comb teeth positioned below the treadway helps to prevent trips and falls by allowing for a seamless movement as the elevator aligns with the landing.

When the comb teeth are properly positioned below the treadway, they engage with the steps or the landing surface appropriately, helping to maintain their functionality while reducing the risk of snagging or catching clothes or limbs. This is particularly important in maintaining safety standards in elevator operations.

In contrast, if the teeth were at the same level or above the treadway, it could create a hazard, increasing the likelihood of accidents when passengers enter or exit the vehicle. Therefore, placing the comb segment teeth below the upper surface is a critical design feature for efficient and safe elevator operation.