In California, vehicles cannot have flashing lights unless there's a specific rule that allows it.

This law outlines when and how flashing lights can be used on vehicles. You're allowed to use flashing turn signals to show you're turning or moving, or if your vehicle is disabled or parked close to the road. You can also use them as a warning for hazards or accidents, for emergency vehicles, or during a funeral procession. If a car is broken down on the road, the vehicle should automatically use its turn signals as warning lights if the system is working. Trailers or semitrucks can flash their lights if they break away from their towing vehicle, and hazard lights can signal for help with special flashing patterns.

Farm vehicles, when traveling at 25 miles per hour or less and showing a slow-moving vehicle sign, can have amber turn signals that flash at the same time to act as warning lights.

This law allows motorcycles to have a headlamp that can switch between high and low brightness quickly, between 200 to 280 times per minute. However, this flashing or modulation is not allowed during night time or when it's dark.

This law explains that a person cannot be held legally responsible in a civil lawsuit just because they used or didn't use their turn signal lights according to certain specified guidelines. However, they still can be held responsible if other rules about required vehicle devices are broken.

This law allows vehicles to have alarm systems that can make any of the vehicle's lights flash. The alarm system must work according to certain rules starting in another section of the law.

This law allows certain setups for lights on the back of a vehicle. Vehicles may have one central amber light at the rear that blinks faster as the vehicle slows down. Additionally, vehicles can have two amber lights on the rear that flash together up to four times within four seconds when the car begins to decelerate, but these lights shouldn't turn on at any other time. The lights must be placed at specific heights and their brightness is limited. Brake lights can also blink up to four times when the brakes are applied.

This law requires every authorized emergency vehicle to have at least one red light at the front, which must be visible from 1,000 feet away. This light should always be on. Additionally, these vehicles can also use red lights that flash, revolve, or stay steady on the front, sides, or back as needed.

This law allows emergency vehicles to have a system that flashes their high-beam headlights alternately between the two front lights. This flashing system should only involve the high-beams, not any other lights. High-beams are defined as headlights bright enough to see people and vehicles 350 feet away. The flashing lights can only be used when the vehicle is on an emergency call, following the rules of another specific law (Section 21055).

This section outlines the use of flashing amber warning lights on tow trucks. Tow trucks must have these lights when towing disabled vehicles, except for tractor-trailer combinations. They can use these flashing lights when helping a disabled vehicle, or when towing and moving slower than usual traffic speeds. However, on freeways, they can only flash these lights if there's a significant traffic hazard.

This law states that an automobile dismantler's tow vehicle is allowed to have flashing amber warning lights.

These lights can be used at the back of the tow vehicle when it is towing a car and traveling slower than other traffic on the road.

This law allows vehicles used by highway authorities or bridge and highway districts to display flashing amber warning lights. These lights can be shown at the front, sides, or rear of the vehicle when they are parked or working on the highway for maintenance, inspection, survey, or construction tasks.

This law requires every school bus transporting children to have a flashing red light system. School buses made after September 1, 1992, must also have a stop signal arm, and those built after July 1, 1993, need an amber warning light system in addition to the red lights. School buses made before these dates can have these features but aren't required to. The California Department of Motor Vehicles must set rules for the stop signal arm, ensuring they meet federal standards. A stop signal arm is a device that extends from the bus to alert other drivers not to pass while children are getting on or off.

This law states that if a school bus is being used to transport people of any age who have developmental disabilities, certain signal systems on the bus—specifically the amber light, flashing red light, and stop signal arm—should only be used according to specific rules set out in other sections, namely Sections 22112 and 22454.

This law allows a school bus driver to use their turn signal lights to alert others while reversing. Both the front and rear turn signals on each side of the bus have to flash at the same time to ensure clear communication to motorists and pedestrians.

This California law allows school buses to have a white strobe light that can be seen from any direction. The strobe light should only be used when visibility goes below 500 feet due to bad weather conditions like fog, rain, or dust. However, it should not be used at night just because it's dark.

The specific type and installation details for these strobe lights are determined by regulations set by the department by a specified date. School buses can only have these strobe lights after those regulations are in place.

This law explains when emergency vehicles can use specific lights to manage traffic. Authorized emergency vehicles can have a flashing white light to control traffic signals. Vehicles used by peace officers and certain probation officers can also have a steady or flashing blue light for additional warning. However, probation officers must complete a special training course before using a blue light. The law clarifies it doesn't grant probation officers more power for high-speed chases or change training for such pursuits. Additionally, no other vehicles can use lights designed to control traffic signals.

This law allows authorized emergency vehicles to use various warning lights. They can use flashing amber lights on any side. Police or traffic officers' vehicles can have steady or flashing white lights above the roofline. Emergency vehicles can also have up to two flashing white lights above and below the roofline in front. These special lights are additional to any flashing headlamps allowed by another law.

This law allows disaster service workers to use flashing amber warning lights on their vehicles when responding to emergencies. Before using these lights, workers must complete a safety training course. When the amber lights are not in use, they should be covered or removed.

This law allows emergency or disaster service vehicles operated by the Red Cross to use flashing amber warning lights when they are at the scene of an emergency or disaster. Vehicles that are not being used for emergency response cannot display these lights.

This law allows certain vehicles to use flashing amber warning lights. Public utility vehicles and their authorized representatives can use these lights when working on public utility projects if they're parked on a highway or moving slower than regular traffic. This includes work like cutting or trimming trees nearby. Additionally, vehicles owned by public transit operators can use flashing amber lights when helping a disabled bus and parked on a highway.

This law allows vehicles involved in working on oil or gas pipelines to use flashing amber warning lights. They can do this when parked on the highway or when they have to drive slower than usual traffic. This is for safety reasons and must follow specific guidelines in another section, Section 25268.

If a vehicle is using equipment to lift personnel for work like building construction, maintenance, or tree trimming nearby, it can use flashing amber warning lights. This is allowed either when parked on the road or moving slowly compared to the other traffic.

This law allows vehicles that are specifically used for cleaning up hazardous substance spills, and are contracted by the Department of Transportation, to use flashing amber warning lights. These lights can be displayed on the front, sides, or back of the vehicle, but only while the vehicle is actively cleaning up the spill. When not actively engaged in cleanup work, the lights must be covered or removed.

This law allows vehicles used by a county agriculture department, or their authorized representatives, to use flashing amber warning lights. They can use these lights when they are parked on a highway or moving more slowly than other traffic due to working on weed control or pest detection.

This law allows armored cars to have red lights that can only be turned on during an armed robbery attempt. The use of red lights does not make the armored car an emergency vehicle. All other driving laws that apply to regular vehicles also apply to armored cars.

If trucks are towing houses or buildings on any highway, they are allowed to use flashing amber lights on the front, sides, or back to warn other drivers.

If a coroner or deputy coroner is at the scene of a violent highway death, they are allowed to use flashing amber warning lights on their vehicle. These lights can be shown either at the front or rear of the vehicle to alert others.

This law allows repair vehicles belonging to sanitary or county sanitation districts to use flashing amber warning lights when parked on a highway for facility repairs. However, these lights must be turned off when the vehicle is moving.

This law allows state-owned vehicles, used by state officers or employees for work on aqueducts, levees, or stream measurements, to use flashing amber lights. These lights can be used when the vehicle is parked in a way that partially blocks traffic or when driving slower than normal traffic speed.

This law allows vehicles used by mosquito or pest abatement districts to use flashing amber warning lights while they are parked or working on the highway to disperse insecticides. This is for safety, alerting other drivers to their presence on the road.

This law states that a flashing amber warning light can only be used on a vehicle if there is an unusual traffic hazard present.

In California, it is generally illegal for anyone to use a flashing or steady red warning light on their vehicle. The only exceptions are when allowed by another law (Section 21055) or if there is an extreme hazard.

If a vehicle or a pilot car is required to assist with transporting oversized or overweight items as stated in specific permits, these vehicles must have flashing amber warning lights. These lights need to be active while actually moving the load. Additionally, when the pilot car is not being used for this purpose, the lights must be either removed or covered.

This law allows vehicles involved in moving livestock across or along public roads to use flashing amber warning lights. These lights can be shown on the front, sides, or rear of the vehicle, and they are permitted when the vehicle is stopped near the livestock or moving with them along the road.

This law says that certain vehicles, like those owned by the city or by animal protection organizations, can use flashing amber lights for safety. This is allowed when they're parked on the road dealing with dead or injured animals, or if they're driving slower than traffic because they're handling loose livestock.

This law allows publicly owned vehicles that are used for enforcing animal control laws to use flashing or revolving amber warning lights. These lights can be used on the front, sides, or rear of the vehicle. The lights should be used when the vehicle is actively enforcing animal control laws and is either parked on the road or moving slower than usual traffic speeds.

This law permits rural mail carriers to use flashing amber warning lights on their vehicles when they stop on the road to deliver mail. These lights can be displayed at the front and back of the vehicle to alert others of the stopped or stopping vehicle.

This law allows school buses, owned and run by large school districts (more than 400,000 daily attendance) in California, to use a flashing amber light on the back when moving slowly to measure the distance between the school and a student's home. This helps alert other drivers that the vehicle is traveling slower than normal traffic flow.

This law allows vehicles owned by cable TV companies to use flashing amber lights when their employees are working on cable facilities. These lights can be used when the vehicles are parked on a highway or moving slower than traffic.

"Cable television company" is defined as anyone transmitting TV programs to subscribers for a fee.

If you drive a truck or truck tractor carrying certain large loads, you can install a flashing amber warning light on it. You can use this light if the vehicle, including its load, is over 75 feet long and there's a risk of causing a traffic hazard.

This law states that buses operated by public agencies or under specific permits can have crime alarm lights to signal a crime occurring on the bus. These lights are additional lamps added to the front and rear of the bus, flashing simultaneously when activated by a non-audible flasher system. They should only be used if a crime is happening or has just occurred on the bus.

This law allows certain vehicles owned by private, nonprofit organizations to have a flashing amber light system. These vehicles must be designed to carry more than eight people, including the driver, and serve people with intellectual or physical disabilities. The organizations must be certified by the Department of Rehabilitation or licensed by the State Department of Developmental Services.

When these vehicles are used to transport people with disabilities to or from training or activity centers, they can use the flashing amber lights while parked on a highway and loading or unloading passengers. The law also applies to vehicles rented, leased, or chartered by the organization.

This law allows vehicles used by police, sheriff’s offices, or other government agencies to have flashing or revolving amber lights when enforcing parking laws. These lights can be used on the front, sides, or rear of the vehicle. The lights are specifically for when these vehicles are stopped on a street or moving slower than normal traffic while doing their job.

This law allows private security vehicles on private roads to display flashing amber lights in emergencies to help save lives or protect property.

Private security cars on highways can have these lights if they are clearly marked with 'PRIVATE SECURITY' but can't use the lights on roads unless a police officer instructs them to.

If a vehicle uses these lights illegally, an officer can demand their removal.

To put these lights back on after breaking the law, you must get OK from the Highway Patrol.

This law allows garbage collection vehicles operated by or working with a local government to use flashing amber lights when they are stopped on a street collecting trash or when they are driving slowly between stops at 10 miles per hour or less.

This law allows privately owned emergency water tender vehicles to use flashing amber lights for safety when providing contract services to public agencies. The lights can be used when the vehicle is parked in a way that blocks traffic, moving slower than usual traffic, or entering/crossing a road. However, the lights should not be on when the vehicle is moving with normal traffic flow unless it is following a fire engine or other emergency vehicle. When not in use, the lights must be covered.

This law allows vehicles owned or operated by licensed contractors or construction companies to use flashing amber lights when working on or near highways. These lights can be on the front, sides, or rear of the vehicle and are intended for situations where the vehicle is stopped on a highway or moving slower than regular traffic. However, whether these lights are used or not cannot be used in court to claim someone was negligent or for assigning fault.