Transmission Gear Indicator problems of the 2015 Toyota Prius

The transmission gear shift is dangerously designed. The shifter will move into a gear positions even if it transmission does not actually shift into the gear. Whenever the handle is released, it springs back to the central position, whether the transmission is in gear or not, so the driver does not know if the transmissions is actually in gear or not--or if in gear, which gear. The driver is expected to look at the instrument panel so see what gear is highlighted in the display. I rented a Prius for a week and numerous times, I thought I had shifted into drive (or reverse), but when I pressed on the accelerator, nothing happened because it had not gone into the selected gear, and I did not know that because the shift lever always springs back to center position, whether the transmission is in gear or not. One time, at night, I was making a three-point u-turn, shifted into drive, turned the wheel to the left, stepped on the accelerator, and suddenly the car was turning to the right! panic¿slam on the brakes. Then I realized the transmission had not shifted into drive and I was rolling backwards. If the driver feels the shift lever go into a gear, the car should be in that gear; if it does not go into that gear, then the shift lever should not move into the position; and once in gear, the shift lever should stay in position, not spring back to center.