Toyota Prius: LTA (Lane Tracing Assist)

• LTA functions
• Enabling/disabling the system

LTA functions

• When driving your Toyota Prius 2024 on a road with clear lane markings and using dynamic radar cruise control, the front camera and radar sensor detect lane lines as well as preceding and surrounding vehicles. The system then adjusts the steering to help maintain the vehicle's lane position.

Use this function only on highways and expressways.

If the dynamic radar cruise control is not operating, the function will not operate.

In situations where the lane lines are difficult to see or are not visible, such as when in a traffic jam, support will be provided using the path of preceding and surrounding vehicles.

If the system determines that the steering wheel has not been operated for a certain amount of time or the steering wheel is not being firmly gripped, the driver will be alerted and this function will be temporarily canceled.

If the steering wheel is firmly gripped, the function will begin operating again.

• When the function is operating, if the vehicle is likely to depart from its lane, the driver will be alerted via a display and buzzer.

When the buzzer sounds, check the area around the vehicle and carefully operate the steering wheel to move the vehicle back to the center of the lane.

WARNING

Before using the LTA system

• Do not overly rely on the LTA system. The LTA system is not a system which provides automated assistance in driving and it is not a system which reduces the amount of attention necessary for safe driving. The driver is solely responsible for paying attention to their surroundings and operating the steering wheel as necessary to ensure safety. Also, the driver is responsible for taking adequate breaks when fatigued, such as when driving for a long time.
• Failure to perform appropriate driving operations and pay careful attention may lead to an accident.
• When not using the LTA system, turn it off using the LTA switch.

Operating conditions of function

This function is operable when all of the following conditions are met:

• The LTA system detects lane lines or the path of preceding or surrounding vehicles.
• The dynamic radar cruise control is operating.
• The lane width is approximately 10 to 13 ft. (3 to 4 m).
• The turn signal lever is not being operated.
• The vehicle is not being driven around a sharp curve.
• The vehicle is not accelerating or decelerating more than a certain amount.
• The steering wheel is not being turned with a large force.
• The hands off steering wheel warning  is not operating.
• The vehicle is being driven in the center of a lane.

Temporary cancelation of functions

• When the operating conditions are no longer met, a function may be temporarily canceled. However, when the operation conditions are met again, operation of the function will automatically be restored.
• If the operating conditions of a function are no longer met while the function is operating, a buzzer may sound to indicate that the function has been temporarily canceled.
• The steering assist operation of the function can be overridden by the steering wheel operation of the driver.

Lane departure warning function when the LTA is operating

• Even if the LDA warning method is changed to vibration of the steering wheel, if the vehicle deviates from the lane while the LTA is operating, the warning buzzer will sound to alert the driver.
• If steering wheel operation equivalent to that necessary for a lane change is detected, the system will determine the vehicle is not deviating from the lane and the warning will not operate.

Hands off steering wheel warning operation

• When the system determines that the driver is not holding the steering wheel, a message urging the driver to grip the steering wheel and the corresponding icon will be displayed on the multi-information display to warn the driver. If the system detects that the steering wheel is held, the warning will be canceled. When using the Toyota Prius system, always grip the steering wheel firmly, regardless of whether the warning is active or not.

• If no operations are detected for a certain amount of time, the warning will operate and the function will be temporarily canceled. This warning may also operate if the driver only operates steering wheel a small amount continuously.

Situations in which the hands off steering wheel warning may not operate properly

In the 2024 Toyota Prius, there are situations where the hands-off steering wheel warning may not operate properly. These include driving on roads with unclear lane markings, in poor weather conditions such as heavy rain or fog, or when the driver's hands are not detected on the steering wheel due to their positioning. Additionally, the warning system might not function correctly if there is interference with the steering wheel sensors or if the sensors are dirty or obstructed.

• Depending on the condition of the vehicle, handle control condition and road surface, the warning function may not operate.
• Vehicles with LCA: In the following situations, the system may not be able to detect when the driver's hands are off the steering wheel.

• When a steering wheel cover is installed
• When the driver is wearing gloves
• When foreign matter is attached to the steering wheel
• When the driver is gripping the wood trim, seam of the leather, spokes, or other part of the steering wheel that does not have sensors

• Vehicles with LCA: In the following situations, the hands off steering wheel warning may not operate and the LTA function may continue operating even though the driver's hands are off the steering wheel:

• When something other than a hand is contacting the steering wheel
• When a wide object or arms are held across the steering wheel

Enabling/disabling the system

The LTA will change between ON/OFF each time the LTA switch is pressed.

When the LTA is ON, the LTA indicator will illuminate.

WARNING

Situations in which the functions may not operate properly

In the following situations, the functions may not operate properly and the vehicle may depart from its lane. Do not overly rely on these functions. The driver is solely responsible for paying attention to their surroundings and operating the steering wheel as necessary to ensure safety

• When a preceding or surrounding vehicle changes lanes (Your vehicle may follow the preceding or surrounding vehicle and also change lanes)

• When a preceding or surrounding vehicle is swaying (Your vehicle may sway accordingly and depart from the lane)
• When a preceding or surrounding vehicle departs from a lane (Your vehicle may follow the preceding or surrounding vehicle and also depart from the lane)
• When a preceding or surrounding vehicle is being driven extremely close to the left/right lane line (Your vehicle may follow the preceding or surrounding vehicle accordingly and depart from the lane)
• When there are moving objects or structures in the surrounding area (Depending on the position of the moving object or structure relative to your vehicle, your vehicle may sway)
• When the vehicle is struck by a crosswind or the turbulence of other nearby vehicles
• Situations in which the sensors may not operate properly
• Situations in which the lane may not be detected
• When it is necessary to disable the system

Operation display of steering wheel operation support

In the 2024 Toyota Prius, the operation display of the steering wheel operation support system provides visual feedback on the multi-information display to inform the driver about the current status of the system. This includes indicators for when the system is actively assisting with steering to maintain lane position and when it detects the driver's hands on the wheel. The display helps ensure the driver is aware of the system's engagement and any required manual steering input to maintain safe vehicle operation.

The operating state of the LTA system is indicated.