Lexus CT (2021 year). Manual in english — page 13

329

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4-5. Using the driving support systems

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RSA (Road Sign Assist)



RSA recognizes specific road signs
using the front camera and provides
information to the driver via the multi-
information display.

If the system judges that the vehicle is being driven over the speed limit, perform-
ing prohibited actions, etc. in relation to the recognized road signs, it alerts the
driver using a warning display and warning buzzer

*

.

*

: This setting needs to be customized.



: If equipped

Summary of function

WARNING

■

Before using the RSA

Do not rely solely upon the RSA system. RSA is a system which supports the driver by

providing information, but it is not a replacement for a driver’s own vision and aware-

ness. Drive safely by always paying careful attention to the traffic rules.
Inappropriate or negligent driving could lead to an unexpected accident.

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4-5. Using the driving support systems

After the front camera recognizes a sign, it is displayed on the multi-information
display when the vehicle passes the sign.

●

When the driving assist system infor-
mation is selected, a maximum of 3
signs can be displayed. (



P. 104)

●

When other than the driving assist
system information is selected, a
speed limit sign or an all canceled
sign can be displayed. (



P. 104)

A no overtaking sign and a speed

limit sign with supplemental mark are

not displayed. However, if signs other

than speed limit signs are recog-

nized, they are mentioned in a stack

under the current speed limit sign.

Indication on the multi-information display

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4-5. Using the driving support systems

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The following types of road signs, including electronic signs and blinking signs,
are recognized.

A non-official (not meeting the Vienna Convention) or a recently introduced traffic

sign may not be recognized.

Types of recognized road signs

Type

Multi-information display

Speed limit begins/ends

Speed limit with sup-

plemental mark

(Displayed simulta-

neously with speed

limit)

(Display example)

Wet

Rain

Ice

On/off ramp

*

1

Supplemental mark

exists

(Contents not recog-

nized)

No overtaking begins/ends

No-entry

*

2

All canceled

(All restrictions canceled. Returns to default

road regulation.)

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4-5. Using the driving support systems

*

1

: If the turn signal indicator is not operated when changing lanes, the mark does not dis-

play.

*

2

: Vehicles with navigation system.

In the following situations, the RSA system alerts the driver using a warning dis-
play.

●

When the vehicle speed exceeds the speed warning threshold applied to the
speed limit of the sign displayed on the multi-information display, the sign
color becomes inverted.

●

If it is detected that your vehicle is overtaking when a no overtaking sign is dis-
played on the multi-information display, the sign flashes.

●

Vehicles with navigation system: When the RSA system recognizes a no-entry
sign and detects that the vehicle has entered a no-entry area based on the
map information of the navigation system, the no-entry sign flashes.

Depending on the situation, traffic environment (traffic direction, speed, unit)
may be detected incorrectly and a warning display may not operate properly.

■

Automatic turn-off of RSA sign display

One or more signs automatically turn off in the following situations.

●

A new sign is not recognized for a certain distance.

●

The road changes due to a left or right turn, etc.

Warning display

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■

Conditions in which the function may not operate or detect correctly

In the following situations, RSA does not operate normally and may not recognize signs,

display the incorrect sign, etc. However, this does not indicate a malfunction.

●

The front camera is misaligned due to a strong impact being applied to the sensor, etc.

●

Dirt, snow, stickers, etc. are on the windshield near the front camera.

●

In inclement weather such as heavy rain, fog, snow or sand storms

●

Light from an oncoming vehicle, the sun, etc. enters the front camera.

●

The sign is dirty, faded, tilted or bent, and if an electronic sign, the contrast is poor.

●

All or part of the sign is hidden by the leaves of a tree, a pole, etc.

●

The sign is only visible to the front camera for a short amount of time.

●

The driving scene (turning, lane change, etc.) is judged incorrectly.

●

Even if it is a sign not appropriate for the currently traveled lane, such a sign exists

directly after a freeway branches, or in an adjacent lane just before merging.

●

Stickers are attached to the rear of the preceding vehicle.

●

A sign resembling a system compatible sign is recognized.

●

The vehicle is driven in a country with a different direction of traffic.

●

Side road speed signs may be detected and displayed (if positioned in sight of the front

camera) while the vehicle is traveling on the main road.

●

Roundabout exit road speed signs may be detected and displayed (if positioned in sight

of the front camera) while traveling on a roundabout.

●

Vehicles without navigation system: The speed information displayed on the meter and

that displayed on the navigation system may be different due to the navigation system

using map data.

■

When driving vehicle in country with different speed unit

Since RSA recognizes signs based on the set unit of the meter, it is necessary to change

the set unit of the meter. Adjust the set unit of the meter to the speed unit of signs in the

current location. (



P. 742)

■

Turning the system on/off

■

Speed limit sign display

If the power switch was last turned off while a speed limit sign was displayed on the multi-

information display, the same sign displays again when the power switch is turned to ON

mode.

■

Customization

Setting (e.g. speeding warning threshold) can be changed.

(Customizable feature:



P. 742)

Select

on

of the

multi-information display (



P. 104)

Press on the steering wheel.

1

2

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4-5. Using the driving support systems

Dynamic radar cruise control



In vehicle-to-vehicle distance control mode, the vehicle automatically acceler-
ates and decelerates to match the speed changes of the preceding vehicle even
if the accelerator pedal is not depressed. In constant speed control mode, the
vehicle runs at a fixed speed.
Use the dynamic radar cruise control on freeways and highways.

●

Vehicle-to-vehicle distance control mode (



P. 337)

●

Constant speed control mode (



P. 342)

Indicators
Display
Set speed
Vehicle-to-vehicle distance switch
Cruise control switch



: If equipped

Summary of functions

1

2
3
4
5

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WARNING

■

Before using dynamic radar cruise control

Driving safely is the sole responsibility of the driver. Do not rely solely on the system,

and drive safely by always paying careful attention to your surroundings.
The dynamic radar cruise control provides driving assistance to reduce the driver’s

burden. However, there are limitations to the assistance provided.

Set the speed appropriately depending on the speed limit, traffic flow, road conditions,

weather conditions, etc. The driver is responsible for checking the set speed.

Even when the system is functioning normally, the condition of the preceding vehicle as

detected by the system may differ from the condition observed by the driver. There-

fore, the driver must always remain alert, assess the danger of each situation and drive

safely. Relying on this system or assuming the system ensures safety while driving can

lead to an accident, resulting in death or serious injury.

■

Cautions regarding the driving assist systems

Observe the following precautions, as there are limitations to the assistance provided

by the system.

Failure to do so may cause an accident resulting in death or serious injury.

●

Assisting the driver to measure following distance

The dynamic radar cruise control is only intended to help the driver in determining

the following distance between the driver’s own vehicle and a designated vehicle

traveling ahead. It is not a mechanism that allows careless or inattentive driving, and it

is not a system that can assist the driver in low-visibility conditions. It is still necessary

for driver to pay close attention to the vehicle’s surroundings.

●

Assisting the driver to judge proper following distance

The dynamic radar cruise control determines whether the following distance

between the driver’s own vehicle and a designated vehicle traveling ahead is within a

set range. It is not capable of making any other type of judgement. Therefore, it is

absolutely necessary for the driver to remain vigilant and to determine whether or not

there is a possibility of danger in any given situation.

●

Assisting the driver to operate the vehicle

The dynamic radar cruise control has limited capability to prevent or avoid a collision

with a vehicle traveling ahead. Therefore, if there is ever any danger, the driver must

take immediate and direct control of the vehicle and act appropriately in order to

ensure the safety of all involved.

■

To avoid inadvertent dynamic radar cruise control activation

Switch the dynamic radar cruise control off using the “ON/OFF” button when not in

use.

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4-5. Using the driving support systems

WARNING

■

Situations unsuitable for dynamic radar cruise control

Do not use dynamic radar cruise control in any of the following situations.

Doing so may result in inappropriate speed control and could cause an accident result-

ing in death or serious injury.

●

Roads where there are pedestrians, cyclists, etc.

●

In heavy traffic

●

On roads with sharp bends

●

On winding roads

●

On slippery roads, such as those covered with rain, ice or snow

●

On steep downhills, or where there are sudden changes between sharp up and down

gradients

Vehicle speed may exceed the set speed when driving down a steep hill.

●

At entrances to freeways and highways

●

When weather conditions are bad enough that they may prevent the sensors from

detecting correctly (fog, snow, sandstorm, heavy rain, etc.)

●

When there is rain, snow, etc. on the front surface of the radar sensor or front camera

●

In traffic conditions that require frequent repeated acceleration and deceleration

●

During emergency towing

●

When an approach warning buzzer is heard often

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4-5. Using the driving support systems

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This mode employs a radar sensor to detect the presence of vehicles up to
approximately 100 m (328 ft.) ahead, determines the current vehicle-to-vehicle
following distance, and operates to maintain a suitable following distance from
the vehicle ahead.

Note that vehicle-to-vehicle distance will close in when traveling on downhill slopes.

Example of constant speed cruising
When there are no vehicles ahead

The vehicle travels at the speed set by the driver. The desired vehicle-to-vehicle dis-

tance can also be set by operating the vehicle-to-vehicle distance switch.

Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appears

When a vehicle is detected running ahead of you, the system automatically deceler-

ates your vehicle. When a greater reduction in vehicle speed is necessary, the system

applies the brakes (the stop lights will come on at this time). The system will respond to

changes in the speed of the vehicle ahead in order to maintain the vehicle-to-vehicle

distance set by the driver. Approach warning warns you when the system cannot

decelerate sufficiently to prevent your vehicle from closing in on the vehicle ahead.

Example of acceleration
When there are no longer any preceding vehicles driving slower than the set
speed

The system accelerates until the set speed is reached. The system then returns to con-

stant speed cruising.

Driving in vehicle-to-vehicle distance control mode

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4-5. Using the driving support systems

Press the “ON/OFF” button to acti-
vate the cruise control.

Radar cruise control indicator will come

on and a message will be displayed on

the multi-information display.
Press the button again to deactivate the

cruise control.
If the “ON/OFF” button is pressed and

held for 1.5 seconds or more, the system

turns on in constant speed control

mode. (



P. 342)

Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
approximately 50 km/h [30 mph])
and push the lever down to set the
speed.

Cruise control “SET” indicator will come

on.
The vehicle speed at the moment the

lever is released becomes the set speed.

Setting the vehicle speed (vehicle-to-vehicle distance control mode)

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To change the set speed, operate the lever until the desired set speed is dis-
played.

Increases the speed
Decreases the speed

Fine adjustment: Momentarily move
the lever in the desired direction.
Large adjustment: Hold the lever up or
down to change the speed, and release
when the desired speed is reached.
In the vehicle-to-vehicle distance con-
trol mode, the set speed will be
increased or decreased as follows:



For Europe
Fine adjustment: By 5 km/h (3.1 mph)

*

1

or 5 mph (8 km/h)

*

2

each time the lever is

operated
Large adjustment: Increases or decreases in 5 km/h (3.1 mph)

*

1

or 5 mph (8 km/h)

*

2

increments for as long as the lever is held



Except for Europe
Fine adjustment: By 1 km/h (0.6 mph)

*

1

or 1 mph (1.6 km/h)

*

2

each time the lever is

operated
Large adjustment: Increases or decreases in 5 km/h (3.1 mph)

*

1

or 5 mph (8 km/h)

*

2

increments for as long as the lever is held

In the constant speed control mode (



P. 342), the set speed will be increased

or decreased as follows:

Fine adjustment: By 1 km/h (0.6 mph)

*

1

or 1 mph (1.6 km/h)

*

2

each time the lever is

operated
Large adjustment: The speed will continue to change while the lever is held.

*

1

: When the set speed is shown in “km/h”

*

2

: When the set speed is shown in “MPH”

Adjusting the set speed

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4-5. Using the driving support systems

Pressing the switch changes the vehi-
cle-to-vehicle distance as follows:

Long
Medium
Short

The vehicle-to-vehicle distance is set

automatically to long mode when the

power switch is turned to ON mode.
If a vehicle is running ahead of you, the preceding vehicle mark will also be displayed.

Select a distance from the table below. Note that the distances shown corre-
spond to a vehicle speed of 80 km/h (50 mph). Vehicle-to-vehicle distance
increases/decreases in accordance with vehicle speed.

Changing the vehicle-to-vehicle distance (vehicle-to-vehicle distance
control mode)

Preceding
vehicle mark

1

2
3

Vehicle-to-vehicle distance settings (vehicle-to-vehicle distance con-
trol mode)

Distance options

Vehicle-to-vehicle distance

Long

Approximately 50 m (160 ft.)

Medium

Approximately 40 m (130 ft.)

Short

Approximately 30 m (100 ft.)

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Pulling the lever toward you cancels
the speed control.

The speed control is also canceled when

the brake pedal is depressed.

Pushing the lever up resumes the
cruise control and returns vehicle
speed to the set speed.

However, cruise control does not

resume when the vehicle speed is

approximately 40 km/h (25 mph) or

less.

When your vehicle is too close to a
vehicle ahead, and sufficient automatic
deceleration via the cruise control is
not possible, the display will flash and
the buzzer will sound to alert the driver.
An example of this would be if another
driver cuts in front of you while you are
following a vehicle. Depress the brake
pedal to ensure an appropriate vehicle-
to-vehicle distance.

■

Warnings may not occur when

In the following instances, warnings may not occur even when the vehicle-to-
vehicle distance is small.

●

When the speed of the preceding vehicle matches or exceeds your vehicle
speed

●

When the preceding vehicle is traveling at an extremely slow speed

●

Immediately after the cruise control speed was set

●

When depressing the accelerator pedal

Canceling and resuming the speed control

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2

Approach warning (vehicle-to-vehicle distance control mode)

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4-5. Using the driving support systems

When constant speed control mode is selected, your vehicle will maintain a set
speed without controlling the vehicle-to-vehicle distance. Select this mode only
when vehicle-to-vehicle distance control mode does not function correctly due
to a dirty radar sensor, etc.

With the cruise control off, press and
hold the “ON/OFF” button for 1.5
seconds or more.

Immediately after the “ON/OFF” but-

ton is pressed, the radar cruise control

indicator will come on. Afterwards, it

switches to the cruise control indicator.
Switching to constant speed control

mode is only possible when operating

the lever with the cruise control off.

Accelerate or decelerate, with
accelerator pedal operation, to the
desired vehicle speed (at or above
approximately 40 km/h [25 mph])
and push the lever down to set the
speed.

Cruise control “SET” indicator will come

on.
The vehicle speed at the moment the

lever is released becomes the set speed.
Adjusting the speed setting:



P. 339

Canceling and resuming the speed setting:



P. 341

Selecting constant speed control mode

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■

Dynamic radar cruise control can be set when

●

The shift position is in D.

●

Vehicle speed is at or above approximately 50 km/h (30 mph).

■

Accelerating after setting the vehicle speed

The vehicle can accelerate by operating the accelerator pedal. After accelerating, the

set speed resumes. However, during vehicle-to-vehicle distance control mode, the vehi-

cle speed may decrease below the set speed in order to maintain the distance to the pre-

ceding vehicle.

■

Automatic cancelation of vehicle-to-vehicle distance control mode

Vehicle-to-vehicle distance control mode is automatically canceled in the following situ-

ations:

●

Actual vehicle speed falls at or below approximately 40 km/h (25 mph).

●

VSC is activated.

●

TRC is activated for a period of time.

●

When the TRC system is turned off.

●

The sensor cannot detect correctly because it is covered in some way.

●

Pre-collision braking is activated.

If vehicle-to-vehicle distance control mode is automatically canceled for any other rea-

son, there may be a malfunction in the system. Contact any authorized Lexus retailer or

Lexus authorized repairer, or any reliable repairer.

■

Automatic cancelation of constant speed control mode

Constant speed control mode is automatically canceled in the following situations:

●

Actual vehicle speed is more than approximately 16 km/h (10 mph) below the set vehi-

cle speed.

●

Actual vehicle speed falls below approximately 40 km/h (25 mph).

●

VSC is activated.

●

TRC is activated for a period of time.

●

When the TRC system is turned off.

●

Pre-collision braking is activated.

If constant speed control mode is automatically canceled for any other reason, there may

be a malfunction in the system. Contact any authorized Lexus retailer or Lexus autho-

rized repairer, or any reliable repairer.

■

Brake system operation sound

If the brakes are applied automatically while the vehicle is in vehicle-to-vehicle distance

control mode, a brake system operation sound may be heard. This does not indicate a

malfunction.

■

Warning messages and buzzers for dynamic radar cruise control

Warning messages and buzzers are used to indicate a system malfunction or to inform

the driver of the need for caution while driving. If a warning message is shown on the

multi-information display, read the message and follow the instructions. (



P. 671)

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4-5. Using the driving support systems

■

When the sensor may not be correctly detecting the vehicle ahead

In the case of the following and depending on the conditions, operate the brake pedal

when deceleration of the system is insufficient or operate the accelerator pedal when

acceleration is required.

As the sensor may not be able to correctly detect these types of vehicles, the approach

warning (



P. 341) may not be activated.

●

Vehicles that cut in suddenly

●

Vehicles traveling at low speeds

●

Vehicles that are not moving in the same lane

●

Vehicles with small rear ends (trailers with no load on board, etc.)

●

Motorcycles traveling in the same lane

●

When water or snow thrown up by the surrounding vehicles hinders the detecting of

the sensor

●

When your vehicle is pointing upwards

(caused by a heavy load in the luggage com-

partment, etc.)

●

Preceding vehicle has an extremely high

ground clearance