I am looking for research, if it exists, relevant to the question of whether it is more safe to habitually use signals whenever one turns or instead to think about situations more specifically and use signals only on some turns, i.e., when necessary due to other vehicles etc.
To me I admit the former seems obviously correct.
But some have argued that that approach amounts to thoughtlessness, which is bad.
Is there… something… objective… I can bring to this discussion?
I assume this is a followup to your thread Should turn signals be used in this situation? (So anyone who just wants to weigh in with an opinion can do it there.)
Now that you bring it up, I too am curious whether there is any objective support for one approach or the other. But I wouldn’t be surprised if there isn’t.
This is the official advice in the UK:
Thoughtlessness isn’t bad. Ingrained habit, or training, or reflex are much more reliable mechanisms for ensuring that a desirable response occurs than having people think about it each time the occasion arises.
The driver who has to think about whether to put his indicator on is a poor driver because he has to think about whether to put his indicator on. He shouldn’t have to think about it.
I can’t prove that having the signal on is better.
However, I can’t think of a valid argument for not putting it on. Does continually having to decide whether or not to use a signal increase over-all alertness? I really doubt it.
Here is the Arizona law:
28-754. Turning movements and required signals
A. A person shall not turn a vehicle at an intersection unless the vehicle is in proper position on the roadway as required in section 28-751, or turn a vehicle to enter a private road or driveway or otherwise turn a vehicle from a direct course or move right or left on a roadway unless and until the movement can be made with reasonable safety. A person shall not so turn any vehicle without giving an appropriate signal in the manner provided by this article in the event any other traffic may be affected by the movement.
Note the boded part. If no other vehicle is affected by the movement, the signalling requirement appears to be vacated.
Do you think it’s safer for someone to “habitually” stop at all stop signs and red lights, or only do so when they think (“when necessary due to other vehicles etc”) they need to?
That explains it! I lived in Arizona for a decade, and I can attest that Arizona drivers assiduously avoid indicating turns. While one assumes they’re simply conserving precious blinker fluid, it would be nice if Arizonans’ ardor for conservation extended other resources such as power and water.
In Phoenix, there’s a lot of drifting between lanes and swerving across five or six lanes of freeway to reach an exit. Some Arizonans are better at driving and some are better at not sucking up resources, but man–the bar is low in Phoenix.
Every time I shift lanes I check my blind spot in that direction, even if I am absolutely positive there is no one there. I don’t make a calculation as to whether it is worth it to glance over my shoulder, it is an absolutely ingrained reflex. It has saved me from a terrible collision perhaps fifty or sixty times over the past forty years. The rest of the time it was wasted effort.
[ul]
[li]The signal is intended for others (and not just cars; pedestrians are also relying on your signal) – not for you. [/li]
[li]If you decide not to use it, the only valid reason would be that you don’t see anyone else.[/li]
[li]The person who most needs to see your turn signal is the person you don’t see.[/li]
[li]People who always see everything and take everything into account are not super alert drivers; they are self-deluded.[/li][/ul]