I think that's exactly the problem. Some things you cannot let become an automatic / unconscious habit, especially when safety is involved.

There's some good discussion here on the topic. Japan's rail workers point and speak, because it keeps the safety checks in the attentive part of your brain. When things go automatic / unconscious, you tend to miss or gloss over things. This is not what you want while driving.

https://news.ycombinator.com/item?id=18952193

Even pilots are taught to point and say their checks out loud during pre-flight. And flying happens to be one of the safest ways to travel.