Although the use of turn signals is required by law in most US states, the majority of drivers consider it an optional recommendation. This disregard is most evident in California, where drivers are notorious for refusing to announce their intentions. This is not just a minor infraction. This is a cultural quirk that transportation experts often point to as a major cause of confusion and collisions.
Hamish Reid captures this feeling perfectly in his blog California Driving: A Survival Guide. He explained that the turn signals on many West Coast cars are vestigial organs, meaning they are useless in daily driving, and are only kept if the owner needs to resell the car to an out-of-state buyer who might actually be looking for a car.
Although national statistics on signaling compliance are surprisingly scarce, the available data paint a disturbing picture of driver behavior in North America. About 25% of the time, drivers do not indicate a turn at an intersection. Lane changes are even worse. The only comprehensive study, conducted in Dayton, Ohio, found that drivers failed to signal nearly half of their lane changes, 48 percent of the time.
Here are seven specific scenarios where you’re statistically the least likely to use indicators, and why doing so can cause problems.
The illusion of safety on quiet roads
Human behavior changes depending on who is watching. John Sullivan, a researcher at the University of Michigan’s Transportation Research Institute, found that drivers are more likely to follow traffic rules when they are surrounded by other vehicles.
“If you’re in an area where there’s a lot less traffic, you’re going to have a lot less signaling,” Sullivan noted after conducting a large-scale study on the subject in 2014. The data shows that drivers are nearly five times more likely to signal on major and secondary roads than on quiet local roads.
This is a dangerous assumption. Thinking that it is safe to jump signaling on a quiet country road or suburban street is a fatal error of judgment. Insurance data from Esurance shows that more accidents occur within 25 miles (40 km) of a driver’s home than anywhere else. In addition, fatal accidents occur more often on rural roads than in busy urban centers. Just because there is less traffic does not mean there is no risk.
The Right Turn Bias
ドライバーは驚くほど熱心に左折の合図をします。 カナダのトリニティ・ウェスタン大学のハロルド・フォー氏が主導した2013年の研究によると、ブリティッシュコロンビア州では、参加者の実に94.8パーセントが左折車線から左折する際に合図をしたという。
右折とは対照的だ。 Fawの調査で最も成績が悪かったのは右折専用レーンから右折するピックアップトラックの運転手で、signal rateわずか74パーセントだった。
この違いは論理的です。 左折は本質的により危険です。 道路の真ん中で減速または停止し、対向車の進路を横切る必要があります。 信号は、後続のドライバーに停止していることを警告し、他の車両に車線に進入していることを警告します。 歩行者がいる四差路交差点では、誰もがこのリマインダーの恩恵を受けます。 右折は一般に、害のない、リスクの低い操作とみなされています。 この認識を理由に、過失で切符を切られるのをやめないでください。
The Contagion of Bad Habits
我们是社会性动物，即使是开车。 Faw对繁忙十字路口的研究表明，signaling behavior具有传染性。 研究发现，跟随有indicators的车辆的驾驶员的信号使用率比跟随未打signal的车辆的驾驶员高出约 6%。
这种潜意识建模解释了很多。 如果你前面的车无视规则，从统计数据来看，你更有可能做同样的事情。 这种动态有助于解释为什么某些地区的驾驶文化（例如加利福尼亚州）似乎始终忽视标准礼仪。
The Comfort of the Queue
在同样繁忙的十字路口，Faw发现了跳过signal的另一个强烈动机。 与前面没有车辆接近十字路口的司机相比，紧跟在前方车辆后面停车的司机发出右转信号的可能性要低 7%。
当您在专用右转车道上排队时，我们会假设您的意图是显而易见的。 每个人都知道您正在右转，因为您前面的每个人都是如此。 那么有什么意义呢？ 这个假设是合乎逻辑的，但结果可能是灾难性的。 你可能会认为行人知道你要转弯，却把他们撞倒了，因为他们以为你是直行。 该信号不适用于您身后的车辆； 它适用于路上的其他人。
Mechanical failure and human error
Turn signal technology has remained largely unchanged since the 1940s. Engineers built a steering column mechanical switch that relies on the physical rotation of the steering column and automatically cancels the signal after turning. This mechanism often fails when changing lanes or merging. This is why you often see a Cadillac turn signal right in front of you during the last 47 miles (76 kilometers).
In a 2006 survey by Response Insurance, 17% of drivers who admitted to failing to signal their lights cited “forgetting to turn off their lights” as the reason.
Richard Ponziani, a veteran automotive engineer from Ohio, decided to solve this problem using a software solution called Intelliturn. Instead of relying on a mechanical click on the steering column, Intelliturn notifies the vehicle’s computer when a turn is complete. Ford licenses this technology for use in many trucks and SUVs. Ponziani also authored a study looking at lane changing patterns in Ohio. To prove the need for an automatic reminder system, he spent a year driving around Dayton and recording his signal habits. His observations lead to the next point.
The “Excitement” Factor
Ponziani氏はオハイオ州で1年間にわたる調査を実施し、2,000件の車線変更に関するデータを記録した。 結果？ 48％は合図なしでexecuted。 この統計は実際、信号を出さなかったと主張するドライバーを対象とした2006年のResponse Insurance調査よりもはるかに優れており、観察データが自己申告よりも悪い習慣を明らかにする可能性があることを示唆しています。
なぜ信号を出さなかったのかと尋ねると、インタビュー対象者はつまらない言い訳をした。 「時間がない」が42％、次いで「怠惰」（23％）、「重要ではない」（11％）となった。 しかし、最も気がかりな回答は回答者の 7% で、「運転の興奮が高まる」ためsignalはしないと答えた。
あなたはこれらのドライバーを見たことがあるでしょう。 彼らはアーケードのレーシング ゲームでハイスコアを追いかけているかのように、4 車線を蛇行しながら進みます。 ホンダ シビックに乗りたいと考えているマリオ アンドレッティにとって、この混乱は刺激的です。 それ以外の人にとって、高速道路は興奮の源ではありません。 これは、仕事を終えて、できれば生きて帰宅するためのメカニズムです。
Case Against Driving Without Signals
We are stuck in transition. Self-driving cars are promised connected to a wireless network, which will probably save us all, but until that future arrives, you’re still behind the wheel. And in the meantime, your turn signal is arguably your most important communication tool.
It is not just a courtesy. It is a primary defense mechanism.
“A seat belt saves you in an accident, but a turn signal protects you from an accident,” says Ponziani. The difference is important. Seat belts are reactive. Turn signals are proactive. They stop the crash before it starts. The tragedy, as Ponziani points out, is that we’ve built this life-saving technology into every car on the road, yet treat it as an optional extra.
Data problem
There are no clear and reliable statistics on how many accidents are directly caused by failure to use turn signals. The data is messy. It’s scattered. But the logic is simple. Better communication between drivers reduces collisions.
It is dangerous to assume that signaling is unnecessary in certain situations. It’s a risk you take with your life and the lives of others. The risk is not worth the convenience of keeping your left hand on the steering wheel.
Public pressure works
If individual willpower is not enough, perhaps social pressure is enough.
A public service campaign around turn signals could actually change behaviour. Research supports this. In an experiment conducted on a university campus, the effects of visible reminders were tested. They put up a simple sign that read, “Please Signal and Drive Safely.”
The result was immediate and significant. Signal usage by drivers leaving the parking garage increased from 63% to 87%.
This is a huge change. It shows that people are willing to follow the rules if they are reminded to do so. The infrastructure is there. The technology exists. The only missing variable is the reminder.
Why do we ignore the simplest car safety feature?
