Have You Been Injured? We're Ready to Fight for You.

When Does a Semi-Truck Need To Use Hazard Lights?

Published on Jun 13, 2022 at 8:55 am in Truck Accidents.

When Does a Semi-Truck Need To Use Hazard Lights?

An increasing number of veteran truckers are retiring, leaving many fleet companies needing to recruit newer, less experienced truckers to fill their spots. Many of those tractor-trailer operators with newly minted commercial driver’s licenses have undergone training on operating these big trucks. However, they aren’t familiar with some of the common practices truckers learn to follow as they spend more time on the road and have to deal with unexpected events.

One such industry practice that new truckers are seldom familiar with is truckers’ tendency to use their hazard lights. There are a few different situations in which it may be customary for tractor-trailer operators to use hazard lights, which we’ll detail throughout the remainder of this article.

What Types of Hazard Lights Do Tractor-Trailers Have?

Semi-trucks have amber-hued hazard lights, which are sometimes referred to as 4-way flashers, much like any other passenger car on the road. These emergency lights can be found on each of the four corners of a tractor-trailer and flash simultaneously. They serve the purpose of warning others of potential dangers that lie ahead on the road that could cause a truck collision.

How Do Truckers Utilize Their Hazard Lights?

If you ever take note of a grouping of truckers on the roadway, you’ll notice that many of them have their hazard lights on. If you perform an internet search trying to make sense of why this is the case, you’ll encounter a plethora of reasons why truckers use their flashers, including:


When Truckers Are Traveling Slower Than the Posted Speed Limit

Tractor-trailer operators may reduce their speed under a few different circumstances, including when:

  • They’ve been made aware that a potentially hazardous situation lies ahead (i.e., wildlife in the roadway or any accident occupying a traffic lane)
  • Operating their truck through a road construction zone
  • They’re traveling along a heavily congested stretch of a roadway
  • There’s inclement weather that affects roadway conditions
  • Their truck is struggling to climb a hill given how heavy their load is
  • They’re experiencing mechanical trouble

Kentucky is one of many states where it’s lawful for truckers to operate their tractor-trailers while running their hazard lights. While this may be good to know if you primarily run a local route, long-haul truckers should take time to apprise themselves of whether it’s lawful to run their hazard lights as they venture into new states.

When They Pull Over or Park

Truckers may find themselves needing to pull over on the shoulder because they suddenly feel unwell or their truck isn’t performing up to par, and they want to inspect to see if they can identify what the issue is. Additionally, truckers may pull over at a rest or truck stop or other welcoming location to take their mandatory rest periods.

It’s commonplace for truckers to turn on their hazard lights in either scenario described above. They do so largely to call attention to their presence, which is similar to the reason why utility workers will often exit their service vans or trucks and place cones both in front and to the rear of their vehicles before they commence work in the field. A trucker may, for example, illuminate their hazard lights so that a wrecker coming to tow their truck can better identify them.

To Communicate With Others

Although it’s illegal to do so, many motorists will flash their headlights or high beams at oncoming traffic to warn them of impending danger, like a speed trap zone being actively monitored by police. Truckers communicate with one another in much the same way drivers do by flashing their hazard lights.

It should be noted that truckers’ communication using their lights isn’t just restricted to their hazard ones. They also use their headlights and turn signals to call attention to their next moves or to give you the go-ahead to execute your plans. Truckers also like when motorists communicate in kind by using their vehicle’s onboard lights similar to them.

Some examples of ways truckers use their tractor-trailers lights to communicate include:

  • Flashing their lights twice in quick succession to call attention to danger ahead
  • Flickering headlights to give a passenger car operator the go-ahead that they have ample space to pass them or that they’ve cleared your vehicle

When They’re Carrying Hazardous Materials or Wide Loads

You can often readily identify a trucker carrying hazardous materials because they are operating a tanker truck instead of a tractor-trailer. They’ll also generally have a placard affixed to the rear portion of their trailer, warning other motorists what substance they’re carrying and of the flammability risk it poses.

Also, flatbed trucks are often used to carry cargo such as concrete barriers earmarked for placement along the highway in Louisville, recently cut down tree trunks that will be shaped into telephone poles, and mobile or manufactured homes.

Many truckers who operate tanker or flatbed trucks tend to leave their hazard lights illuminated for the same reason a tractor-trailer operator would on an interstate’s shoulder or when parked in a lot.

Our truck accident attorneys have learned a lot about the trucking industry in handling injury cases over the years. We’ve learned that truckers often use their hazard lights merely to call attention to their presence and warn others to keep a distance.

How Does a Truck Accident Attorney Fit Into Your Case?

Just because it’s been customary for truckers to use their hazard lights in certain ways with their colleagues doesn’t mean that everyone will get the message they’re trying to send. Mixed-up signals can lead to collisions in Louisville.

You may have a valid compensation claim to file if you can attribute the injuries you suffered to some type of trucker negligence.

You must meet specific requirements to establish such liability per Kentucky law. This is one of the many requirements that a truck accident lawyer will discuss with you during your complimentary initial consultation.

You need to take certain steps immediately following your crash to preserve your legal rights. Schedule your free case review with us at Thomas Law Offices today so that we can apprise you of what those are.

Free Case Evaluation

At Thomas Law Offices, our personal injury attorneys recognize that our potential clients are likely going through some of the most difficult times of their lives. We don't want you to have to worry about paying out of pocket for legal advice when you're just starting to learn your legal rights and options. That's why we provide free case evaluations. We'll offer our expert advice about your potential case and walk you through how we can help you.

Call us or fill out the form below to tell us about your potential case and a personal injury lawyer will get back to you as quickly as possible.

Meet Our Founder

Tad Thomas - Trial Lawyer

Tad Thomas

Managing Partner

Tad Thomas has dedicated his practice to representing plaintiffs in various types of civil litigation, including personal injury, business litigation, class actions, and multi-district litigation.

After graduating with his law degree in 2000 from Salmon P. Chase College of Law at Northern Kentucky University, Mr. Thomas immediately opened his own private practice and began representing injury victims.

In 2011, Thomas Law Offices was established in Louisville, Kentucky. Over the past decade, Mr. Thomas has expanded his firm and now has offices in three additional locations: Cincinnati, Ohio, Columbia, Missouri, and Chicago, Illinois. He is also a frequent lecturer on topics like trial skills and ethics and technology.

Legal & Firm News

When Prior Authorization Leads to Harm Caused by Delayed Care

In March 2023, the American Medical Association (AMA) released the results of a survey conducted on the impact of health insurance prior authorization (PA) on patient care and outcomes. The survey results revealed shocking information about the extent to which health insurance companies control the type of medical care patients receive. At Thomas Law Offices, […]

Read More

How Do I Sue a Hospital for Medical Negligence?

Medical errors and other types of health care professional negligence have soared in recent years. Data recently published by the National Institutes for Health (NIH) shows that at least 251,000 patient deaths are estimated to be attributable to physician mistakes or other types of medical errors annually. Countless others fall ill or suffer injuries while […]

Read More

Ohio Car and Booster Seat Laws

According to the National Highway Traffic Safety Administration (NHTSA), traffic crashes are the leading cause of death and disability for children (aged 0-14) in the United States. But most of these deaths can be prevented. When we put our children in the car, we owe it to them to give them the safest experience possible. […]

Read More
Tad Thomas on The National Crime Victim Bar Association
National Civil Justice Institute - Trustee
Tad Thomas on Lawyer Minds
Tad Thomas on American Association for Justice
Southern Trial Lawyers Association
Illinois Trial Lawyers Association
Ohio Association for Justice
Kentucky Justice Association
Fellows of the Litigation Counsel of America
Martindale Hubbell Preeminent
2021 Public Justice Member
AAJ Masters of Trial Law: Champion