Final answer:
The two design choices that significantly affect elevator service are the acceleration rate when the elevator starts moving and the constant velocity it maintains during transit.
Step-by-step explanation:
The design choices that significantly affect the speed and quality of elevator service involve the velocity and acceleration of the elevator. Understanding the physics of an elevator in motion informs how these choices impact ride comfort and efficiency. Acceleration of an elevator, either upward or downward, can influence the perceived comfort of the ride and the dynamic loads on the elevator system. On the other hand, when an elevator is moving upward or downward with a constant velocity, the comfort may improve, and dynamic loads may be reduced since there is no change in acceleration. However, accelerating too quickly or attaining too high a constant velocity can be undesirable from both comfort and safety perspectives.
Therefore, two design choices that considerably affect elevator service are how quickly the elevator accelerates (which impacts initial comfort and load) and the maximum constant velocity it achieves during travel (impacting the duration of the travel and overall efficiency).