Turn signals are the rare piece of driving safety advice that everyone agrees on. They are also the rare piece of driving safety advice that a surprising number of people ignore anyway.
The O’Sullivan Law Firm sees what happens when drivers treat communication like an optional feature. Many turning and lane-change crashes are not “mysteries.” They are predictable outcomes of unpredictable driving. And nothing makes a vehicle more unpredictable than changing direction with no warning.
A blinker is not just a courtesy. It is a tiny, low-effort way to buy everyone around you time.
In real-world driving, the difference between “I saw that coming” and “where did they come from?” is often one to two seconds. A turn signal is one of the few tools you have that gives everyone those seconds without costing you anything.
Drivers often assume, “I always signal.” But observational and naturalistic studies consistently show a gap between what we think we do and what we actually do.
That “after it starts” number matters. From a safety standpoint, that is basically the driving equivalent of announcing, “By the way, I am already in the middle of doing the thing.”
A turn signal is one of the few safety tools designed specifically to prevent misunderstandings between drivers.
NHTSA has also studied how turn signals reduce certain rear-end crashes. In one large crash-data analysis, NHTSA found amber (yellow/orange) rear turn signals were associated with a 5.3% reduction in involvement in specific two-vehicle crashes where signaling is relevant (turning, merging, changing lanes, entering or leaving a parking space), compared to red turn signals.
That study is about signal visibility, but the takeaway is bigger: when a signal is clear and timely, it helps prevent crashes in the exact moments when direction changes create risk.
Colorado does not treat turn signals as optional.
Under Colorado’s “Turning movements and required signals” law, drivers must signal before turning or moving right or left on a roadway when it can be done with reasonable safety, and the signal must be given continuously for at least the last 100 feet in urban/metropolitan areas, and at least 200 feet on certain higher-speed roads. Colorado also includes a roundabout exception unless otherwise posted.
That legal requirement matters after a crash, because when someone fails to signal and a collision follows, the question becomes simple: was that driver acting reasonably, or did they remove another driver’s ability to react?
It’s another good reason for a dash camera.
In a law office, the “why” shows up in patterns, not excuses. Some common ones:
They believe it is obvious.
Drivers think their next move is predictable because it is predictable to them. In other words, they’re inconsiderate jerks that think they own the road!
They do not see anyone nearby.
People check quickly, see no car, and skip the signal. But they miss motorcycles, cyclists, and pedestrians. They also miss the car two lanes over that is closing fast.
They are rushing and cutting steps.
Signaling feels like “extra” when someone is impatient. Ironically, impatience is exactly when you need to communicate more, not less.
They copy what they see.
One observational study found a “modeling effect”: drivers were more likely to use signals when the driver ahead of them used signals. In plain English, bad habits are contagious, but so are good ones!
Safe driving is not only about being careful, it is about being predictable.
A practical rule that works in real life:
It is not complicated. It is just consistent.
Failure-to-signal collisions often involve lane changes, left turns, and side impacts, the kinds of crashes that can cause lasting injuries and huge disputes with insurance companies. The argument is usually predictable too: the at-fault driver claims the other person “came out of nowhere,” or that the crash was unavoidable.
This is where experience matters. The O’Sullivan Law Firm handles serious injury cases across Colorado, and they know how these crashes actually happen, how to prove fault, and how to push back when insurers try to minimize what a victim has lost. At the O’Sullivan Law Firm you get a lawyer, not a call center.
If you were hurt in a Colorado crash, call or text (303) 388-5304 for free advice.
