Do Motorcycles Need Turn Signals in Missouri?

Kenneth Powell
Jan 26
9 min read

In Missouri, motorcycles are not explicitly required by state law to have mechanical turn signals installed to be considered street legal. However, this simple answer hides a much more complicated reality for riders. The law absolutely requires you to signal your intent to turn or change lanes, and if your motorcycle is equipped with turn signals, they must be fully functional.

The nuance here is that the law mandates the act of signaling, not a specific piece of technology. You are legally permitted to use hand and arm signals. This implies that logically, if you lack turn signals, you must manually signal your intent to turn.

But this distinction becomes a serious point of contention after an accident. Insurance adjusters may use a lack of mechanical signals—even if you were legally compliant by using hand signals—as a pretext to argue you were partially at fault and deny or reduce your claim.

If a vehicle equipment issue is complicating your motorcycle accident claim, call Powell Law Firm at (314) 293-3777 for a clear assessment of your case.

Key Takeaways for Missouri Motorcycle Turn Signal Laws

Mechanical turn signals are not legally required on all motorcycles in Missouri. However, if your bike was manufactured with signals, they must be functional to pass a vehicle inspection.
You must always signal your intent to turn or change lanes. If you do not have electronic signals, you are required to use legally defined hand and arm signals to comply with the law.
Lack of electronic signals will be used against you in an accident claim. Insurance adjusters will argue that not having mechanical signals makes you partially at fault to reduce or deny your compensation, even if you signaled by hand.

The Statutory Framework: Missouri’s If Equipped Doctrine

Many riders understandably assume that because cars require blinkers, motorcycles must as well. This isn't the case. Missouri law carves out a specific exception for motorcycles.

To be considered street legal, a motorcycle in Missouri must have a few core pieces of equipment. These are the non-negotiable requirements outlined in the Missouri Revised Statutes, Chapter 307, Vehicle Equipment Regulations. Think of these as the absolute baseline for legal operation on public roads:

Headlight: Must be functional at all times.
Taillight and Brake Light: Your bike needs at least one red taillamp and a functioning brake light.
Horn: Must be in good working order for warning purposes.
Brakes: At least one adequate set of brakes is required.
Mirrors: A mirror is required if your position on the bike prevents you from seeing the road behind you.

You'll notice turn signals are absent from that list. This is where Missouri's if equipped doctrine comes into play. The Missouri Department of Revenue’s Motor Vehicle Inspection (MVI) manual clarifies this standard. If a motorcycle comes from the manufacturer with turn signals, those signals must be maintained in proper working condition to pass inspection. You cannot legally ride with broken or disconnected signals if the bike was designed to have them.

Conversely, if you build a custom chopper or ride a vintage bike manufactured before signals became standard equipment (generally pre-1973), you are not required to retrofit it with turn signals.

Manual vs. Mechanical: The Legal Obligation to Communicate Intent

Choosing to ride a motorcycle without electronic turn signals does not mean you may turn or change lanes without warning. The legal responsibility to communicate your intentions to other drivers remains absolute.

Missouri Revised Statute 304.019 states that a driver must give an appropriate signal before turning or suddenly decreasing speed. The statute explicitly allows these signals to be given by "hand and arm or by a signal light or signal device." This means your arm is considered a legally valid signal device.

To be compliant, you must use the correct, legally recognized hand signals in Missouri:

Left Turn: Extend your left arm and hand straight out horizontally.
Right Turn: Extend your left arm and hand upward at a 90-degree angle from the elbow.
Stop or Slow Down: Extend your left arm and hand downward.

While legally sufficient, relying on hand signals presents practical challenges, particularly in dense urban environments like St. Louis or on the winding, hilly roads of the Ozarks. Attempting to signal while simultaneously managing the clutch, throttle, and front brake during stop-and-go traffic demands a high level of skill and compromises your control of the motorcycle. This physical difficulty is a key reason why failing to signal—whether due to a broken bulb or a hand occupied with the clutch—is a moving violation and is also used as evidence of negligence in an accident claim.

Negligence and Liability: How Missing Signals Affect Accident Claims

This is where the legal theory meets the harsh reality of a personal injury case. Imagine you are in an accident that wasn't your fault where the other driver ran a stop sign. However, your custom bike doesn't have turn signals. Even though you were legally compliant by using hand signals, the other driver's insurance company now has an angle to exploit.

Their argument will be that your lack of electronic signals made you less visible and your intentions less clear, therefore making you partially responsible for the crash. This is a strategy rooted in Missouri's comparative fault law.

Comparative Fault in Missouri

Missouri uses a pure comparative fault system. This means that after an accident, a jury assigns a percentage of blame to each party involved. Your final compensation is then reduced by your percentage of fault.

Insurance companies and their lawyers are businesses, and part of their business model involves minimizing payouts. They will conduct a thorough investigation to find any evidence that suggests you share blame, and the lack of turn signals on your motorcycle is an easy and frequent target for them. They will likely argue it contributed to the accident, even if the other driver was clearly the primary cause.

The Reasonable Person Standard

In civil court, your actions are judged against what a reasonable person would have done in the same situation.

An insurance company lawyer might ask a jury, "Would a reasonable and prudent motorcyclist choose to ride at dusk or in heavy rain without the benefit of bright, flashing electronic signals?" This is a persuasive argument, turning a legally permissible equipment choice into a suggestion of negligent behavior. The line between what is legal and what is considered safe or non-negligent becomes blurred in a courtroom.

Our firm has significant experience countering these biased arguments. Our role is to keep the focus on the facts. We use accident reconstruction, witness testimony, and other evidence to demonstrate that the presence or absence of mechanical signals was irrelevant to the actual cause of the crash—which is most often the other driver's inattention, distraction, or recklessness.

The "At Home" Perspective: Managing Your Claim After the Incident

You've made it home after the accident, and the adrenaline is wearing off. You are likely in pain and uncertain about what to do next. If the other driver or the police mentioned your lack of turn signals at the scene, take a few steps immediately to protect your potential claim.

Document Your Bike's Condition. Before any repairs are made, take clear, well-lit photographs and videos of your motorcycle from all angles. If you do have signals, document that they were intact before the impact. If you have maintenance records, receipts for new bulbs, or photos of your bike from before the crash, gather them. This evidence helps prove your equipment was in good, legal working order.
Preserve Your Riding Gear. Do not wash or throw away the clothes you were wearing. If you claim you were hand-signaling, a jacket with high-visibility colors or reflective strips on the sleeves becomes a piece of evidence. The same is true for high-visibility gloves.
Follow Up with Witnesses. If anyone at the scene saw the accident, contact them as soon as possible. A witness who states, "I clearly saw the rider put his arm out to signal a left turn," provides a powerful counter-narrative to the insurance company's claims. Get their name and contact information before they forget key details.
Avoid Insurance Traps. An adjuster from the other driver's insurance company will likely call you very soon. They may ask for a recorded statement. We advise declining this until you have spoken with an experienced motorcycle accident attorney. It is easy in these conversations to say something that is easily misconstrued, such as, "I didn't signal because my bike doesn't have signals." An adjuster could twist this to imply you failed to signal at all, conveniently omitting the fact that you used a hand signal.

Cross-Border Riding: Surrounding State Laws

Many Missouri riders enjoy trips that cross state lines into Illinois, Kansas, or Arkansas. Remember that being legal in Missouri does not grant you immunity from the traffic laws in a neighboring state. Your bike's equipment must comply with the laws of the state you are physically riding in.

Illinois: State law in Illinois explicitly states that motorcycles and motor-driven cycles need not be equipped with electric turn signals. Like Missouri, if you don't have them, you are required to use hand signals.
Kansas: The rules in Kansas are much stricter. Kansas statute mandates that every motorcycle manufactured after January 1, 1973, shall be equipped with electric turn signals. Riding a post-1973 custom bike without signals in Kansas could lead to a traffic citation.
Arkansas: Arkansas law does not require motorcycles to be equipped with turn signals, but it does require other key equipment like headlights, brake lights, and mirrors. If you ride without signals, you must use hand signals.

The practical takeaway is this: if you ride a custom or vintage bike without signals and live near a state line, be aware of the laws of your destination. A quick trip across the border could result in an unwanted conversation with law enforcement if you aren't compliant.

Custom Builds, Vintage Bikes, and the Grandfather Myth

The conversation around turn signals frequently involves vintage restorations and custom-built bikes. The laws here are generally straightforward.

For vintage motorcycles, specifically those manufactured before turn signals were standard (generally pre-1973), there is no requirement to retrofit the bike with modern signals. These bikes are grandfathered in, and using proper hand signals is legally sufficient.

For custom choppers and home-built bikes, the same if equipped rule applies. If you build the bike from the frame up and do not install turn signals, you are not legally required to have them in Missouri. You must, however, have all the other mandatory equipment like a headlight, brake light, and horn.

Many riders choose to upgrade their lighting with LED conversions, integrated tail lights, or flush-mount signals for a cleaner look. These are legal in Missouri, but they must meet visibility standards. While statutes may not specify a precise distance for turn signals, a good rule of thumb is that they must be plainly visible from a reasonable distance (typically 300-500 feet) to be considered compliant and effective. If an integrated light is so small or dim that it's difficult to see, it could be deemed insufficient in a civil liability case.

FAQ for Motorcycle Turn Signals in Missouri

Can I use integrated tail light turn signals in Missouri?

Yes, integrated lights are generally permissible. However, they must be bright enough and large enough to be clearly visible as both a brake light and a turn signal from a safe distance. If the signals are too close together or not distinct enough, they could be challenged as unsafe in an accident claim.

If my turn signals are broken, can I just use hand signals to avoid a ticket?

No. If your motorcycle is equipped with turn signals, they must be functional. Operating the vehicle with broken safety equipment is an improper equipment violation. While using a hand signal may prevent a failure to signal ticket, you may still be cited for the broken light itself during a traffic stop or vehicle inspection.

Do I need turn signals to pass the Missouri Motor Vehicle Inspection (MVI)?

It depends. If your bike was manufactured with turn signals, they must be present and working correctly to pass the MVI. If your bike is a vintage or custom build that never had signals, it is not required to have them to pass the inspection.

Are handle-bar end turn signals legal in St. Louis?

Yes, provided they are visible and meet state requirements for color (amber or white for the front). They also must not extend the width of your motorcycle beyond legal limits, although this is rarely an issue with standard handlebar setups.

Does a 50cc scooter require turn signals in Missouri?

Mopeds and scooters classified as motor-driven cycles generally fall under the same equipment rules as motorcycles. If they are equipped with signals from the factory, they must work. If not, hand signals are permissible.

Do Not Let Equipment Technicalities Compromise Your Recovery

Riding a motorcycle represents a unique balance of freedom and personal responsibility. When an accident happens, however, insurance companies frequently try to tip those scales by shifting blame onto the rider. They scrutinize every piece of equipment, looking for any technicality to argue that you were at fault.

You should not be penalized for an accident caused by another driver's carelessness simply because you ride a vintage or custom motorcycle. If you followed Missouri's signaling laws, whether you used your hand or a switch, you have the right to pursue full compensation for your injuries.

If you’ve been injured in an accident where your bike's equipment has become a point of contention, let us review the facts of your case. Call Powell Law Firm today at (314) 293-3777.