Toyota Prius (2023 year). Manual in english - page 20

326

4-5. Using the driving support systems

●

Other road signs

*

: For vehicles with navigation system

●

Speed limit with supplemental mark

*

1

*

1

: Displayed simultaneously with speed limit.

*

2

: Contents not recognized.

*

3

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

does not display.

No-entry

*

Stop

End of prohibition

Wet

Exit ramp on right

*

3

Rain

Exit ramp on left

*

3

Ice

Time

Supplemental mark
exists

*

2

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In the following situations, the RSA system will notify the driver.

●

When the vehicle speed exceeds the speed notification threshold of
the speed limit sign displayed, the sign display will be emphasized
and a buzzer will sound.

●

When the RSA system recognizes a no-entry sign and detects that
the vehicle has entered a no-entry area based on the map informa-
tion of the navigation system, the no-entry sign flashes and a
buzzer will sound.(For vehicles with navigation system)

●

If it is detected that your vehicle is overtaking when a no overtaking
sign is displayed on the multi-information display, the displayed sign
will flash and a buzzer will sound.

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

■

Setting procedure



P. 153

■

Automatic turn-off of RSA sign display

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

●

No sign has been recognized for a certain distance.

●

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

■

Conditions in which the function may not operate or detect correctly

In the following situations, RSA does not operate normally and may not rec-
ognize 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.

●

The contrast of electronic sign is low.

●

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.

●

If a sign not appropriate for the currently traveled lane, but the sign exists
directly after a freeway branches, or in an adjacent lane just before merging.

Notification function

328

4-5. Using the driving support systems

●

Stickers are attached to the rear of the preceding vehicle.

●

A sign resembling a system compatible sign is recognized.

●

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 posi-
tioned in sight of the front camera) while traveling on a roundabout.

●

The front of the vehicle is raised or lowered due to the carried load

●

The surrounding brightness is not sufficient or changes suddenly.

●

When a sign intended for trucks, etc. is recognized.

●

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

●

The navigation system map data is outdated.

●

The navigation system is not operating.

●

The speed information displayed on the meter and on the navigation system
may be different due to the navigation system using map data.

■

Speed limit sign display

If the power switch was last turned off while a speed limit sign was displayed
on the main display or multi-information display, the same sign displays again
when the power switch is turned to ON mode.

■

If “RSA Malfunction Visit Your Dealer” is shown

The system may be malfunctioning. Have the vehicle inspected by any autho-
rized Toyota retailer or Toyota authorized repairer, or any reliable repairer.

■

Customization

Some functions can be customized. (Customizable features: 



P. 670)

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Dynamic radar cruise control



with full-speed 

range



In vehicle-to-vehicle distance control mode, the vehicle automatically
accelerates, decelerates and stops 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 with full-speed range on free-
ways and highways.

●

Vehicle-to-vehicle distance control mode (



P. 333)

●

Constant speed control mode (



P. 340)

Vehicle-to-vehicle distance
switch
Indicators
Multi-information display
Set speed
Cruise control switch



: If equipped

Summary of functions

System Components

1

2
3
4
5

330

4-5. Using the driving support systems

WARNING

■

Before using dynamic radar cruise control with full-speed range

●

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 sur-
roundings.

●

The dynamic radar cruise control with full-speed range provides driving
assistance to reduce the driver’s burden. However, there are limitations to
the assistance provided.
Read the following conditions carefully. Do not overly rely on this system
and always drive carefully.
• When the sensor may not be correctly detecting the vehicle ahead: 



P. 344

• Conditions under which the vehicle-to-vehicle distance control mode

may not function correctly: 



P. 345

●

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 preced-
ing vehicle as detected by the system may differ from the condition
observed by the driver. Therefore, the driver must always remain alert,
assess the danger of each situation and drive safely. Relying solely on this
system or assuming the system ensures safety while driving can lead to
an accident, resulting in death or serious injury.

●

Switch the dynamic radar cruise control with full-speed range setting to off
using the “ON-OFF” button when not in use.

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WARNING

■

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 with full-speed range 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 mecha-
nism 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 with full-speed range 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 neces-
sary 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 with full-speed range does not include
functions which will prevent or avoid collisions with vehicles ahead of your
vehicle. Therefore, if there is ever any possibility of danger, the driver must
take immediate and direct control of the vehicle and act appropriately in
order to ensure the safety of all involved.

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4-5. Using the driving support systems

WARNING

■

Situations unsuitable for dynamic radar cruise control with full-speed
range

Do not use dynamic radar cruise control with full-speed range in any of the
following situations.
Doing so may result in inappropriate speed control and could cause an acci-
dent resulting 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 sen-
sors from detecting correctly (fog, snow, sandstorm, heavy rain, etc.)

●

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

●

In traffic conditions that require frequent repeated acceleration and decel-
eration

●

When your vehicle is towing a trailer

*

 or during emergency towing

*

: Vehicles that can tow a trailer: 



P. 233

●

When an approach warning buzzer is heard often

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This mode employs a radar 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 fol-
lowing distance from the vehicle ahead. The desired vehicle-to-vehi-
cle distance can also be set by operating the vehicle-to-vehicle
distance switch.

When driving on downhill slopes, the vehicle-to-vehicle distance may
become shorter.

Driving in vehicle-to-vehicle distance control mode

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4-5. Using the driving support systems

Example of constant speed cruising
When there are no vehicles ahead

The vehicle travels at the speed set by the driver.

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
decelerates 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 suffi-
ciently to prevent your vehicle from closing in on the vehicle ahead.
When the vehicle ahead of you stops, your vehicle will also stop (vehicle is
stopped by system control). After the vehicle ahead starts off, pushing the
cruise control lever up or depressing the accelerator pedal (start-off opera-
tion) will resume follow-up cruising. If the start-off operation is not per-
formed, system control continues to keep your vehicle stopped.
When the turn signal lever is operated and your vehicle moves to an over-
taking lane while driving at 80 km/h (50 mph) or more, the vehicle will
accelerate to help to overtake a passing vehicle.
The system’s identification of what is an overtaking lane may be deter-
mined solely based on the location of the steering wheel in the vehicle (left
side driver position versus right side driver position.) If the vehicle is driven
to a region where the overtaking lane is on a different side from where the
vehicle is normally driven, the vehicle may accelerate when the turn signal
lever is operated in the opposite direction to the overtaking lane (e.g., if the
driver normally operates the vehicle in a region where the overtaking lane
is to the right but then drives to a region where the overtaking lane is to the
left, the vehicle may accelerate when the right turn signal is activated).

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 constant speed cruising.

1

2

3

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Press the “ON-OFF” button to
activate the cruise control.

Dynamic radar cruise control indi-
cator will come on and a message
will be displayed on the multi-infor-
mation display.
Press the button again to deacti-
vate 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. 340)

Accelerate or decelerate, with
accelerator pedal operation, to
the desired vehicle speed (at or
above approximately 30 km/h
[20 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)

1

2

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4-5. Using the driving support systems

●

Adjusting the set speed by the lever
To change the set speed, operate the lever until the desired set
speed is displayed.

Increases the speed

(Except when the vehicle has
been stopped by system control
in vehicle-to-vehicle distance
control mode)

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 control mode, 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: 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. 340), 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”

●

Increasing the set speed by the accelerator pedal

Accelerate with accelerator pedal operation to the desired vehi-
cle speed.
Push the lever down.

Adjusting the set speed

1

2

1

2

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Pressing the switch changes the
vehicle-to-vehicle distance as fol-
lows:

Long
Medium
Short

Select a distance from the table below. Note that the distances shown
correspond to a vehicle speed of 80 km/h (50 mph). Vehicle-to-vehicle
distance increases/decreases in accordance with vehicle speed.
When the vehicle is stopped by system control, the vehicle stops at a
certain vehicle-to-vehicle distance depending on the situation.

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

Preceding 
vehicle mark

1
2
3

Vehicle-to-vehicle distance settings (vehicle-to-vehicle distance
control 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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4-5. Using the driving support systems

After the vehicle ahead of you
starts off, push the lever up.
Your vehicle will also resume fol-
low-up cruising if the accelerator
pedal is depressed after the vehi-
cle ahead of you starts off.

Pulling the lever toward you
cancels the speed control.

The speed control is also canceled
when the brake pedal is
depressed.
(When the vehicle has been
stopped by system control,
depressing the brake pedal does
not cancel the setting.)

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

Resuming follow-up cruising when the vehicle has been stopped
by system control (vehicle-to-vehicle distance control mode)

Canceling and resuming the speed control

1

2

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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

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 main-
tain 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, etc.

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

Immediately after the “ON-OFF”
button is pressed, the dynamic
radar cruise control indicator will
come on. Afterwards, it switches to
the cruise control indicator.
Switching to constant speed con-
trol 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 30 km/h
[20 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. 336

Canceling and resuming the speed setting: 



P. 338

Selecting constant speed control mode

1

2

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When this function is enabled and the system is operating in vehicle-
to-vehicle distance control mode (



P. 333), when a speed limit sign is

detected, the recognized speed limit will be displayed with an up/
down arrow. The set speed can be increased/reduced to the recog-
nized speed limit by pushing the lever up or down.

●

When the current set speed is
lower than the recognized
speed limit

Push the lever up.

●

When the current set speed is
higher than the recognized
speed limit

Push the lever down.

Dynamic Radar Cruise Control with Road Sign Assist can be enabled/

disabled in 

 on the multi-information display. (



P. 127)

When the Dynamic Radar Cruise Control with Road Sign Assist is
operating, while driving down a hill, the vehicle speed may exceed the
set speed.
In this case, the displayed set vehicle speed will be highlighted and a
buzzer will sound to alert the driver.

Dynamic Radar Cruise Control with Road Sign Assist (vehicles
with RSA [Road Sign Assist])

Enabling/Disabling the Dynamic Radar Cruise Control with Road
Sign Assist (vehicles with RSA [Road Sign Assist])