I watched the driver on either side of me this morning on my way to work. We were stopped waiting for a red light and I could see that both of them were totally focused on the that light. Neither one of them moved their heads and immediately started off when the light turned green. What a wonderful example of blind faith!
Is it really necessary to make shoulder checks while driving? If you expect to pass a driving exam in British Columbia the answer is a definite yes. However, some driving schools are teaching mirror adjustment techniques to replace shoulder checks.