Turn signals are required on motorcycles built for U.S. sale on or after January 1, 1973. Federal Motor Vehicle Safety Standard 108 forced manufacturers to install front and rear signals from that date forward, and most states require those signals to remain on the bike and work. A few narrow exemptions exist for older machines and very low-speed motor-driven cycles, and hand signals fill the gap when mechanical signals aren’t required or have failed.
The 1973 Federal Cutoff
FMVSS 108, codified at 49 CFR 571.108, governs lighting equipment on every motor vehicle sold in the United States, motorcycles included. The standard requires that any motorcycle manufactured on or after January 1, 1973, leave the factory with front and rear turn signal lamps.1National Highway Traffic Safety Administration. NHTSA Interpretation nht76-2.37 Federal law makes it illegal to manufacture or sell a vehicle that doesn’t meet the safety standard in effect on its production date.2Office of the Law Revision Counsel. 49 USC 30112 – Prohibited Conduct
That’s the manufacturing rule. Once a bike is on the road, state vehicle codes take over and generally require that equipment the factory was obligated to install remains present and functional. So if your motorcycle came with turn signals, you almost certainly have to keep them working.
Motorcycles That Don’t Need Turn Signals
Three categories of bikes fall outside the federal mandate. Whether they also fall outside your state’s rules is a separate question.
Pre-1973 Motorcycles
Bikes built before January 1, 1973, were never required by the federal standard to have turn signals from the factory. Many states honor that cutoff and do not require owners of pre-1973 motorcycles to retrofit signals. Some states use a slightly different dividing line, such as 1975. If you ride a vintage machine, check your state’s vehicle code for the exact year that applies.
Low-Speed Motor-Driven Cycles
An amendment to FMVSS 108 effective October 14, 1974, exempted motor-driven cycles whose top speed over one mile is 30 mph or less.1National Highway Traffic Safety Administration. NHTSA Interpretation nht76-2.37 Many mopeds and small-displacement scooters sit in that category. States can still require signals on these vehicles, so the federal exemption doesn’t automatically clear you in every jurisdiction.
Off-Road Motorcycles
Dirt bikes ridden strictly off-road aren’t subject to highway equipment laws. If you want to make one street-legal, that changes: expect to add front and rear turn signals along with a headlamp, tail lamp, brake light, and at least one reflector. Some bikes need a stator upgrade to power everything. Specific requirements vary by state.
Why State Law Still Matters
FMVSS 108 sets the floor for what manufacturers must install. State law controls what riders must have on the road, and states can be more restrictive than the federal standard.
The variations show up in different ways. Some states mandate periodic motorcycle safety inspections that include a lighting check. Others require signals to be self-canceling. A handful don’t require turn signals on motorcycles at all and accept hand signals in their place. Because these rules change and the details matter, look up your state’s current vehicle equipment code or contact your state DMV before you assume you’re covered.
Hand Signals
Hand signals are legally recognized across the country. They become your primary communication tool when your bike is exempt from the turn signal requirement, or when your signals fail mid-ride. Some riders use them alongside working signals for extra visibility in heavy traffic or group rides.
All three standard signals use the left arm:
- Left turn: left arm extended straight out horizontally.
- Right turn: left arm out and bent upward at the elbow, roughly a 90-degree angle.
- Slowing or stopping: left arm extended downward, palm facing behind you.
Most states require you to signal at least 100 feet before a turn or lane change. Some jurisdictions require more distance at higher speeds or set a time-based rule for freeway signaling, so check your state’s driver handbook for the exact threshold.
Keeping Required Signals Working
If your motorcycle has turn signals, whether factory-installed or added later, they have to work. A non-functional signal on a bike that’s required to have one is an equipment violation just the same as having no signal at all. A quick pre-ride look-over should confirm that both front and rear signals flash at a steady rate, that lenses aren’t cracked or heavily fogged, that the switch engages and cancels cleanly, and that the wiring near the steering head and suspension isn’t frayed or pinched. States with mandatory motorcycle inspections check all of these items. Even in states without inspections, an officer can pull you over for a visibly broken signal.
Hyper-flashing, where the signal blinks unusually fast, generally points to a burned-out bulb or a flasher relay that doesn’t match the bulbs installed. FMVSS 108 references SAE specifications setting a compliant flash rate of 60 to 120 flashes per minute; a rate outside that window doesn’t meet the standard.3National Highway Traffic Safety Administration. Interpretation of Federal Motor Vehicle Safety Standard No. 108 – Motorcycle Headlamp Warning Device
Penalties for Riding Without Required Signals
Riding without required or working turn signals is an equipment violation. The exact penalty depends on where you’re stopped. Most jurisdictions issue a traffic citation with a fine typically running from about $25 to $100 or more. Some states use a “fix-it” ticket that gets dismissed once you prove the equipment has been corrected; others treat it as a straight payable fine.
The bigger exposure comes after a crash. An insurance adjuster or opposing attorney will point to the equipment violation as evidence you failed to signal your intentions, which can shift fault toward you. Keeping the signals working costs very little compared to the liability that follows a missing or dead signal in a collision.