The Latest Trends in Child Presence Detection (CPD) Systems | NEXTY Electronics, a Trading Company for Electronic Components and Semiconductors

Child Presence Detection (CPD) systems, which prevent accidents involving children being left behind in vehicles, have rapidly become standard equipment in recent years, primarily through direct detection (*1) technology, due to stricter Euro NCAP evaluations in Europe and legal regulations in various countries. This article aims to provide readers with an interest in CPD with an overview of the overall picture in this field. First, it outlines the background to child presence detection systems as a social issue, legal and regulatory trends in various countries around the world, and the latest technological trends, including millimeter-wave radar, as well as the activities of major manufacturers, before delving into the forefront of the CPD market.

*1: A detection method that directly captures biological signals (see the technology used to abandon infants)

Child abandonment as a social problem

Leaving young children in cars is a serious social issue that goes beyond simple negligence. Behind this is the harsh environment inside a car, which can have a fatal effect on the human body, and the reality that human error cannot be completely prevented.

Hyperthermia, a potentially fatal condition
Even if the outside temperature is around 30°C, the temperature inside a car after the engine is turned off can reach dangerous levels of over 50°C in just 15 to 30 minutes. Compared to adults, infants have underdeveloped thermoregulation mechanisms and their body temperature rises three to five times faster, causing potentially fatal hyperthermia in an extremely short period of time. This is the biggest cause of accidents in which children are left behind.
Sporadic accidents in Europe and the dual role of "technology and systems"
In Europe, cases of young children being left behind in cars have been reported sporadically, and the risk is spreading not only along the Mediterranean coast but also due to the increasing number of heat waves. Recognizing that there are limitations to operational use of shuttle vehicles, countries are promoting the introduction of warning devices and detection technology in addition to raising awareness, and the discussion is shifting toward "complementing human error with technology."
Serious current situation and emerging risks in North America
In the United States, an average of 39 young children die each year after being left behind in a car. According to statistics from the National Safety Council (NSC), more than half of these deaths are due to psychological factors such as "forgetting that a child is still with them when getting out of the car" (forgetfulness syndrome). In response to this serious situation, developing technology to eliminate fatal accidents has become a top priority for automakers in fulfilling their corporate social responsibility (CSR).
Strengthening regulations and social demands in Japan
In Japan, there have been repeated serious accidents in which children have been left behind on shuttle buses to kindergartens and nursery schools. In response to this, the government, led by the Agency for Children and Families, has embarked on legally enforceable measures, such as requiring shuttle buses to install devices to prevent children from being left behind. Consumer safety awareness is currently at an all-time high, and there is a strong demand for the implementation of "technology that compensates for human error" in private cars as well.

Legal and regulatory trends around the world

1. European (EU) regulations and latest trends

Europe's Child Presence Detection (CPD) systems currently have the most advanced evaluation standards and regulatory framework in the world. As of 2026, substantial standardization through the New Car Assessment Program (Euro NCAP) and gradual mandatory implementation through legal regulations are progressing in parallel.

1-1. Major regulatory bodies

Institution Name	Key trends in roles and CPD
European Commission (EC)	[Control center for legal obligations] The European General Safety Regulation (GSR2) will gradually require all new vehicles to be fitted with CPDs, with partial implementation starting in July 2024 and wider adoption planned for 2026.
Euro NCAP	[Accelerator for popularization] CPD evaluations began in 2023, ahead of legal regulations. From 2025, the evaluation will also include detection of intrusion into unlocked cars, encouraging manufacturers to install more advanced technology (such as direct detection) as soon as possible in order to maintain a "5-star" rating.
UNECE (WP.29)	[Unification of technical standards] We aim to harmonize vehicle regulations not only in Europe but also in Japan and other countries internationally. We are currently working on formulating UN regulations (international standards) to prevent heatstroke caused by children left in cars, and once completed, these will serve as the direct technical basis for national regulations such as those of the European Commission.

1-2. Current regulatory situation and latest trends in 2026

The following situation is evident in Europe in 2026:

Euro NCAP 2026 protocol in full operation:
- From 2026, CPD assessment requirements will become even stricter.
- Mandatory "Direct Detection": A condition for high evaluation is that the "movement," "breathing," and "heartbeat" of infants and young children must be directly detected using radar or cameras, rather than indirect methods that rely on door opening and closing history.
- Added challenging scenario: The ability to detect objects even when they are covered with a blanket or hidden between seats is required.
Legal obligations according to GSR2 (General Safety Regulations):
- In Europe, "driver drowsiness and distraction warnings" will be mandatory for all new vehicles from July 2024, and CPD is also being gradually introduced within the GSR framework.
- As of 2026, it has become the industry standard to equip vehicles with high-performance CPDs in order to achieve perfect scores in Euro NCAP, which is ahead of legal regulations.

1-3. Technical requirements and operation (2026 standards)

As of 2026, Child Presence Detection (CPD) has become a de facto mandatory feature in Euro NCAP. It has evolved from a "recommended feature" to a de facto essential feature in order to maintain a high rating (5 stars).

Summary: Position in 2026

Europe leads the world in technology thanks to the Euro NCAP evaluation standards, which emphasize "direct detection." As of 2026, major new cars sold in Europe (especially those aiming for a five-star rating) will be equipped with advanced life detection systems using millimeter-wave radar as standard equipment.

2. US regulations and latest trends

Regulation of child presence detection (CPD) systems in the United States (US) is currently at a major turning point. Under the Infrastructure Investment and Jobs Act (IIJA) of 2021, federal/Congressional mandates are underway, but as of 2026, there is a parallel situation of "delays in regulatory development" and "industry voluntary responses."

2-1. Major regulatory bodies

Institution Name	Key trends in roles and CPD
Federal Government/Congress	[Source of legal force] As part of the Infrastructure Investment and Jobs Act of 2021 (IIJA), the U.S. passed the "Hot Cars Act," which mandates NHTSA to "require warning systems to be installed in all new vehicles."
DOT(2) / NHTSA(3)	[Standards formulation executor] Under a mandate from Congress, the FMVSS is responsible for rulemaking to incorporate CPD requirements into the Federal Motor Vehicle Safety Standards (FMVSS). Although the original deadline (November 2023) has been delayed, the process for publishing the final rules is still ongoing as of 2026.
Consumer groups, Private evaluation	[Market Guardian] Leading organizations such as Kids and Car Safety and Consumer Reports have begun to independently evaluate and recommend CPD, providing an incentive for manufacturers to voluntarily install sensors (such as millimeter-wave radar) even before legislation is complete.

*2: DOT: (Department of Transportation) U.S. Department of Transportation
*3: NHTSA: (Abbreviation for National Highway Traffic Safety Administration) U.S. Department of Transportation Highway Traffic Safety Administration

2-2. Current regulatory situation and latest trends in 2026

The latest situation as of 2026 is as follows:

Delays in Federal Mandates:
NHTSA had originally planned to issue the final rules by November 2023, but as of 2026, the formulation of the final technical standards has been delayed. NHTSA aims to establish broad safety standards (FMVSS) rather than "mandating specific products."
Voluntary industry initiatives (2025 targets):
The Alliance for Automotive Innovation, comprised of major automakers, has voluntarily agreed to make rear seat reminder (warning system) standard equipment in nearly all passenger vehicles sold in the United States by 2025.
Linkage with other countries' regulations and evaluations:
Europe's Euro NCAP will tighten its CPD evaluation requirements from 2026 (such as detecting babies under blankets), which is driving up technical standards in the US market through manufacturers offering global models.

2-3. technology trends

The following technologies are expected to become mainstream in the market in 2026.

Moving to liveness detection:
Systems that simply notify when a door is opened or closed are increasingly being adopted, including those that use millimeter-wave radar (mmWave) and ultra-wideband (UWB) to detect breathing and other subtle movements.
Sensor Fusion:
High-precision systems that combine cameras and radar and can detect even infants covered with blankets while respecting privacy are becoming more common.

Summary: Position in 2026

In the United States, the market is currently being driven by "industry voluntary installation" and "consumer safety awareness" ahead of "legal mandate for full liveness detection." The focus is on whether NHTSA will officially adopt the more advanced "Occupant Detection" as part of the Federal Motor Vehicle Safety Standards (FMVSS).

3. Japanese regulations and latest trends

Japan's regulations regarding Child Presence Detection (CPD) systems are progressing in two stages: making them legally mandatory for shuttle buses and introducing technical standards for regular passenger cars.
As of 2026, installation on buses has been completed, and the system is now in the phase of being harmonized with international standards in order to be adopted in passenger cars.

3-1. Major regulatory bodies

Institution Name	Key trends in roles and CPD
Agency for Children and Families	[Flagsetter for shuttle bus measures] This department oversees the mandatory installation of safety devices on shuttle buses for daycare centers, kindergartens, etc., which came into effect in April 2023. It serves as the control center aiming to achieve 100% installation in a short period of time through the operation of subsidy systems, etc.
Ministry of Land, Infrastructure, Transport and Tourism	[Creating a measure of technology] In line with the Child and Family Agency's mandate, we have formulated the "Administrative Rules for Devices to Support the Prevention of Children from Being Left Behind on Shuttle Buses" (Guidelines). We are also participating in international discussions at the UNECE (United Nations) and considering the future introduction of mandatory safety standards for general passenger vehicles.
JNCAP	[Promoting the evolution of passenger cars] This is a safety evaluation conducted by NASVA (Japan National Agency for Automotive Safety and Victims' Aid). In line with European trends, evaluation of "child abandonment detection" began in fiscal year 2024. In order for manufacturers to receive high ratings from JNCAP, it is becoming common for them to install "direct detection" systems using millimeter-wave radar, etc.

3-2. Current regulatory situation and latest trends in 2026

① Shuttle buses: Completion of mandatory implementation and maintenance (2023 onwards)

Mandatory installation:
Starting in April 2023, it will be mandatory for shuttle buses to kindergartens, daycare centers, special needs schools, etc. to be equipped with safety devices.
Status 2026:
After a one-year transitional period, installation of the devices in almost all applicable vehicles nationwide has been completed as of 2026. Currently, emphasis is being placed on operational aspects such as regular inspections and maintenance to ensure the devices continue to function properly and compliance with the manual.

② General passenger cars: Compliance with international standards and introduction of evaluation

Mandatory installation:
Although it is not currently a legal requirement for general passenger cars, the Ministry of Land, Infrastructure, Transport and Tourism is continuing to consider expanding the "Guidelines for Child Abandonment Prevention Devices" to general passenger cars in line with international regulatory trends (UN regulations and European NCAP).
JNCAP evaluation:
As of 2026, CPD is gradually being incorporated into the safety performance evaluation items for new cars, and automakers are accelerating their efforts to make it standard equipment in order to receive high ratings (5 stars).

3-3. Latest technology trends (2026)

The spread of "auto-detection":
In the early days, the "check-when-disembarking" system (where you press a button at the rear of the bus) was the norm, but as of 2026, the "automatic detection" system, which uses sensors to directly detect children left inside the vehicle, is becoming more common in both regular cars and buses.
Advanced Liveness Detection:
Millimeter-wave radar that captures chest movement and heartbeat due to breathing, and AI-based camera detection are now in practical use, making it possible to detect infants even when they are wrapped in a blanket or in a blind spot.

Summary: Position in 2026

In Japan, the stage has shifted from "enforcing buses" to "spreading to passenger cars" to prevent serious accidents. By 2026, high-performance sensors based on international standards will be installed as standard in new Japanese cars, and technological "monitoring" will become established.

Techniques used in child abandonment

Transition and cutting edge of child presence detection (CPD) technology

As of 2026, child presence detection (CPD) technology in passenger cars has dramatically evolved from the conventional "indirect detection" method, which relies on door opening and closing history and physical weight, to "direct detection" that directly captures biological reactions.

The representative technologies are summarized below.

Comparison of detection technologies to prevent children from being left behind in vehicles (as of 2025)

classification	Detection method	structure	Main features and benefits	Issues and weaknesses
indirect detection	Door opening and closing record	It remembers whether the rear door is opened or closed before driving and notifies you when you exit the vehicle.	It is low cost and can be easily installed on many vehicle models.	It is not possible to determine whether there are any children left.
indirect detection	Weight sensor	The judgment is made by combining seat pressure and door opening and closing history.	Can be shared with seat belt warning.	It is difficult to distinguish from luggage. It is weak when installing a child seat.
directly detection	ULTRASONIC SENSORS	Measures distance and moving objects using reflected ultrasound.	Low cost due to its small size and relatively cheap price.	It is prone to malfunction due to wind and vibration from the air conditioner, and is vulnerable to blind spots.
directly detection	In-car camera + AI	AI analyzes camera footage and determines the condition of the occupants.	You can visually check the situation inside the car.	It cannot be detected if it is hidden in a "blind spot" such as under a blanket or seat.
directly detection	UWB (Ultra Wideband)	Scans biological reactions using ultrashort pulse signals.	Centimeter-level location detection possible. Digital key integration possible.	In the process of becoming popular.
directly detection	millimeter wave radar	High-frequency radio waves detect "chest movement due to breathing."	Currently mainstream. Blankets and other items have high transparency, allowing for privacy.	Complex signal processing techniques are required.

Recent trends in integrated control

There is also a trend in the market towards "sensor fusion" that complements the weaknesses of single-sensor solutions like those mentioned above. Specifically, this approach combines multiple detection methods, such as using millimeter-wave radar to detect biological reactions in blind spots or in obstructed environments, and using cameras to visually grasp the situation inside the vehicle. This type of integrated control reduces the false positives and missed detections that are unavoidable with single methods, and the direction is clear for building highly accurate and reliable safety systems.

Representative case trends (primary information base)

Child Presence Detection (CPD)-related functions are being increasingly implemented in mass-produced vehicles as part of advanced safety equipment (Occupant Monitoring/rear seat confirmation assistance).
In this section, we will organize representative examples that have been released to the market or can be found in official information by method (direct detection/indirect reminder).

1. Typical examples of direct sensing (millimeter wave radar, etc.)

Unlike reminders based on door opening and closing history, this approach uses an in-vehicle radar that captures minute body movements (such as breathing) inside the vehicle to "directly" detect the presence of occupants.

Toyota — Sienna (North America, 2025 model year)

Toyota has announced that the 2025 Sienna for the U.S. market will feature the Advanced Rear Seat Reminder as standard on all grades. This technology uses a 60GHz millimeter-wave radar mounted above the headliner to detect movement in the second and third rows and provides a step-by-step warning (hazard warning/chime → horn → app notification, etc.). [pressroom.toyota.com]

Volvo — EX90

Volvo officially explains that the EX90 is equipped with an interior radar system using multiple radars that covers the entire interior (including the luggage compartment), designed to detect sub-millimeter movements (such as a child's breathing while sleeping). It also suggests that the system could detect attempts to lock the vehicle and, if necessary, provide locking prevention, display a warning, or maintain air conditioning. [volvocars.com]

Tesla — Cabin Radar (Feature Platform)

In its vehicle manual, Tesla explains that the Cabin Radar near the front interior lamps is used to detect occupancy inside the vehicle and supports functions such as passenger detection and the Occupant Classification System (OCS). (Note: The general availability, target vehicle models, and launch date of this CPD function will vary by region, model year, and software.)

2. Typical examples of indirect (Door LOGIC Reminder) and step-by-step (Door LOGIC + Sensor) systems

There are two main types of this system.

(A) Door LOGIC type (indirect): A method that prompts for confirmation when the rear door is opened or closed (does not detect the occupant itself)
(B) Door LOGIC + sensor (step type): The door LOGIC initially warns the driver, and depending on the situation, the in-car sensor detects movement and increases the warning level.

Nissan — Rear Door Alert (RDA): Pathfinder/Rogue, etc.

In an official release, Nissan explained that it will be deploying the "Rear Door Alert (RDA)" system to assist with rear seat security, and that it will alert drivers by displaying messages and sounding a horn based on the rear door opening and closing history.
The Pathfinder's instruction manual also clearly states that the RDA system does not directly detect people or objects in the rear seats, but rather alerts the driver when the door is opened or closed. [usa.nissannews.com][nipathfinder.com]

Honda — Rear Seat Reminder: Odyssey, etc.

Honda's documentation states that the Rear Seat Reminder system is designed to alert the driver with a visual and audible alert when the rear door is opened or closed and the vehicle is off, but that it does not directly detect rear seat occupants. [owners.honda.com][hondainfocenter.com]

Ford — Rear Occupant Alert System (available as a setting)

Ford provides instructions on how to set up the Rear Occupant Alert System (Alert/Horn, etc.) on its support page, and it can be confirmed that this will be provided as a vehicle setting.

Hyundai/Kia — ROA (Rear Occupant Alert)

Hyundai's owner's manual clearly states that the Rear Occupant Alert is a notification based on the rear door opening and closing history, and does not directly detect rear seat occupants (door LOGIC type).
On the other hand, while the owner's manual for Kia describes it as a door LOGIC type, Kia's official release explains that the Telluride's ROA uses ULTRASONIC SENSORS (implementation may vary depending on the vehicle model/year), and that there is a stepped configuration.

Summary

The future created by "multi-layered protection" of technology and people

As outlined in this article, child abandonment detection systems are rapidly evolving into the implementation phase, with sensor technology and AI at their core, against the backdrop of increasingly sophisticated legal regulations and safety assessments in each country.
This issue was once often treated as a result of individual lack of care, but is now being redefined as a societal risk that should be prevented through technology.High-precision biological detection using millimeter-wave radar and instant notification via cloud integration are important elements supporting safety designs that assume human error.

However, technology alone cannot eliminate all risks. The more advanced a system becomes, the more essential it becomes to maximize its effectiveness through "multi-layered defense" in which people, society, and technology each play their respective roles.

The role of technology: Automate in-car live body detection and warnings to prevent oversight
Society's role: Standardizing and popularizing technology adoption through legal regulations and evaluation systems
Individual role: Do not rely too much on the system and always be aware of the need to confirm safety.

As autonomous driving and connected cars become more widespread in the future, these detection systems will likely become more naturally incorporated into vehicles as basic functions.
In order to make "accidents involving people being left behind in cars" a thing of the past, continuous technological innovation and social implementation, as well as the accumulation of awareness among the people who support it, will be more important than ever.

In anticipation of these changes, NEXTY Electronics will contribute to the realization of a safe and secure mobility society by providing comprehensive support for various sensing devices, including millimeter-wave radar, system design support that meets automotive quality standards, evaluation and verification, and the launch of mass production. We do not just "install" technology, but also ensure that it "functions" reliably and is firmly established as a system that can be "continuously used" in the field -- as a partner to achieve this, we will work with our customers to promote multilayered safety.

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Latest Trends in Child Proneness Detection (CPD) Systems

Child abandonment as a social problem

Legal and regulatory trends around the world

1. European (EU) regulations and latest trends

1-1. Major regulatory bodies

1-2. Current regulatory situation and latest trends in 2026

1-3. Technical requirements and operation (2026 standards)

Summary: Position in 2026

2. US regulations and latest trends

2-1. Major regulatory bodies

2-2. Current regulatory situation and latest trends in 2026

2-3. technology trends

Summary: Position in 2026

3. Japanese regulations and latest trends

3-1. Major regulatory bodies

3-2. Current regulatory situation and latest trends in 2026

3-3. Latest technology trends (2026)

Summary: Position in 2026

Techniques used in child abandonment

Transition and cutting edge of child presence detection (CPD) technology

Recent trends in integrated control

Representative case trends (primary information base)

1. Typical examples of direct sensing (millimeter wave radar, etc.)

Toyota — Sienna (North America, 2025 model year)

Volvo — EX90

Tesla — Cabin Radar (Feature Platform)

2. Typical examples of indirect (Door LOGIC Reminder) and step-by-step (Door LOGIC + Sensor) systems

Nissan — Rear Door Alert (RDA): Pathfinder/Rogue, etc.

Honda — Rear Seat Reminder: Odyssey, etc.

Ford — Rear Occupant Alert System (available as a setting)

Hyundai/Kia — ROA (Rear Occupant Alert)

Summary

The future created by "multi-layered protection" of technology and people

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