Initiative details
One of the most common misuses of child car seats for infants and toddlers is slack in the harness. Studies show that nearly one in two children travels with a harness that is too loose, reducing the protective effect of the car seat in a collision. In parallel, many parents also face situations where children unbuckle themselves during a journey.
Even when a child is placed in an approved and correctly installed car seat, slack in the harness can allow forward or sideways movement during an impact, increasing the risk of injury.
This challenge remains widespread and persistent because achieving the harness tension relies entirely on the judgement of parents and caregivers. Determining the harness tension is difficult, particularly in everyday situations involving time pressure, short journeys, or physical limitations. As a result, many children unintentionally travel with insufficiently tightened harnesses despite caregivers’ best intentions and a high level of safety awareness.
Educational campaigns and improved instructions have increased knowledge around correct child restraint use. However, the continued high prevalence of slack in harnesses shows that knowledge alone is not enough to solve the problem. A similar gap exists when children unbuckle themselves during travel, an additional real world challenge for caregivers.
Together, these factors highlight a critical gap between safety recommendations and actual usage. Addressing harness slack, while also supporting caregivers in managing unbuckling events, represents a significant opportunity to improve real world child safety on European roads.
Even when a child is placed in an approved and correctly installed car seat, slack in the harness can allow forward or sideways movement during an impact, increasing the risk of injury.
This challenge remains widespread and persistent because achieving the harness tension relies entirely on the judgement of parents and caregivers. Determining the harness tension is difficult, particularly in everyday situations involving time pressure, short journeys, or physical limitations. As a result, many children unintentionally travel with insufficiently tightened harnesses despite caregivers’ best intentions and a high level of safety awareness.
Educational campaigns and improved instructions have increased knowledge around correct child restraint use. However, the continued high prevalence of slack in harnesses shows that knowledge alone is not enough to solve the problem. A similar gap exists when children unbuckle themselves during travel, an additional real world challenge for caregivers.
Together, these factors highlight a critical gap between safety recommendations and actual usage. Addressing harness slack, while also supporting caregivers in managing unbuckling events, represents a significant opportunity to improve real world child safety on European roads.
Initiative date
Who was/is your target audience?
Children 0-16
Parents
Topic
Knowledge building and sharing
Organisation details
Holmbergs Safety System
Enterprise
Sweden
Halmstad
Contact name
Ottilia Lindell
Telephone number
+46702896352
ottilia.lindell@holmbergs.se
Project activities
If you work together with external partners, list the most important partners and briefly describe their role.
eBuckle by Holmbergs™ has been innovated and developed by Holmbergs, with active involvement from leading global child car seat manufacturers. Their involvement was essential in evaluating harness tension behaviour across different child car seats, particularly for seat models that span wide height ranges, for example seats designed for use from 61 cm to 125 cm. These seats cover multiple usage stages as a child grows, making it especially challenging to ensure that the guiding and reminder function of eBuckle by Holmbergs™ remains consistent and meaningful throughout the entire life of the seat.
Please describe the project activities you carried/are carrying out and the time period over which these were implemented.
The eBuckle by Holmbergs™ initiative focuses on reducing slack in child car seat harnesses and alerting if the child unbuckles by providing active safety support to parents and caregivers during everyday use. eBuckle by Holmbergs™ is designed to guide and remind caregivers to tighten the harness, helping reduce the risk of unintentional slack when securing a child.
The core project activity has been the development of a smart buckle solution that communicates with caregivers through light and sound signals, prompting attention during the harness tightening process. This support is intended to function as a reminder and guidance. The objective is to support consistent tightening behaviour.
The initiative began at the end of 2024 with initial development and prototyping. Throughout 2025, eBuckle by Holmbergs™ was evaluated in a number of different child car seat designs to assess functionality, usability, and suitability for daily family use. In 2026, the project advanced to integration of eBuckle by Holmbergs™ into child car seats, enabling the safety support function to be available as part of the restraint system itself.
The core project activity has been the development of a smart buckle solution that communicates with caregivers through light and sound signals, prompting attention during the harness tightening process. This support is intended to function as a reminder and guidance. The objective is to support consistent tightening behaviour.
The initiative began at the end of 2024 with initial development and prototyping. Throughout 2025, eBuckle by Holmbergs™ was evaluated in a number of different child car seat designs to assess functionality, usability, and suitability for daily family use. In 2026, the project advanced to integration of eBuckle by Holmbergs™ into child car seats, enabling the safety support function to be available as part of the restraint system itself.
In terms of implementation, what worked well and what challenges did you need to overcome?
A key challenge during implementation was addressing the wide variation in the harness tension force across child car seats. Each seat design differs in terms of height limitations, inlays, padding and friction which influences the harness tension. As a result, a single harness tension reference cannot be applied universally. Each child car seat requires individual testing and evaluation to ensure that eBuckle by Holmbergs™ provides a good guidance to tighten the harness. This required close technical collaboration and an iterative validation process.
Another significant challenge was the integration of electronics into a buckle component. The buckle is a highly safety critical component, subject to strict mechanical, durability, and reliability requirements. Ensuring that electronic components could function consistently over the product’s lifetime required extensive engineering development and testing. The electronic features are fully separated from the mechanical system, so the buckle remains fully safe and functional regardless of battery status.
What worked particularly well was the user focus throughout the development. The light and sound cues were developed to be intuitive and supportive rather than distracting or alarming. Continuous evaluation in different child car seat models helped refine the solution and confirm that eBuckle by Holmbergs™ functions as a practical safety support in everyday use. Integrating the technology directly into child car seats also proved effective in ensuring consistent use, supporting caregivers without adding complexity.
Another significant challenge was the integration of electronics into a buckle component. The buckle is a highly safety critical component, subject to strict mechanical, durability, and reliability requirements. Ensuring that electronic components could function consistently over the product’s lifetime required extensive engineering development and testing. The electronic features are fully separated from the mechanical system, so the buckle remains fully safe and functional regardless of battery status.
What worked particularly well was the user focus throughout the development. The light and sound cues were developed to be intuitive and supportive rather than distracting or alarming. Continuous evaluation in different child car seat models helped refine the solution and confirm that eBuckle by Holmbergs™ functions as a practical safety support in everyday use. Integrating the technology directly into child car seats also proved effective in ensuring consistent use, supporting caregivers without adding complexity.
Evaluation
Please summarise how you have evaluated the initiative’s impact (e.g. social media reach, survey, feedback forms, statistics).
The impact of eBuckle by Holmbergs™ has been evaluated primarily through structured testing, real world use, and feedback collection in collaboration with child car seat manufacturers. When eBuckle by Holmbergs™ is integrated into a child car seat model, the solution is evaluated using children across the full approved height range of that specific seat. This includes testing with the smallest and largest children intended to use the seat, as well as children at the defined inlay height limits, to ensure that the guiding and reminder function supports harness tightening throughout the entire life span of the seat.
User testing has been carried out with parents and caregivers in everyday scenarios, allowing observation of the tightening function, how the light and sound guidance is perceived and acted upon during normal use. Feedback from these test users has been collected to assess if the tightening support encourages attention to harness tightening.
eBuckle by Holmbergs™ has also been evaluated and demonstrated together with child car seat ambassadors who are established safety advocates. These ambassadors are administrators of large child car seat communities on social media (Facebook groups). Content shared through these channels has helped raise awareness about harness slack and the importance of harness tightening among a broad audience of caregivers.
These qualitative evaluation methods provide a comprehensive picture of how eBuckle by Holmbergs™ functions in real world conditions and how it contributes to supporting safer harness tightening behaviour.
User testing has been carried out with parents and caregivers in everyday scenarios, allowing observation of the tightening function, how the light and sound guidance is perceived and acted upon during normal use. Feedback from these test users has been collected to assess if the tightening support encourages attention to harness tightening.
eBuckle by Holmbergs™ has also been evaluated and demonstrated together with child car seat ambassadors who are established safety advocates. These ambassadors are administrators of large child car seat communities on social media (Facebook groups). Content shared through these channels has helped raise awareness about harness slack and the importance of harness tightening among a broad audience of caregivers.
These qualitative evaluation methods provide a comprehensive picture of how eBuckle by Holmbergs™ functions in real world conditions and how it contributes to supporting safer harness tightening behaviour.
What has been the effect of the activities?
The effect of eBuckle by Holmbergs™ has primarily been observed through behavioural changes and increased awareness among parents and caregivers, as captured through structured user testing and user feedback. Across evaluations, caregivers report that the light and sound guidance draws attention to harness tightening and encourages them to remove slack more consistently in everyday use.
User feedback indicates that the guidance helps caregivers better understand how tight the harness needs to be, increasing confidence when securing their child in the car seat. Several users noted that the eBuckle by Holmbergs™ made them aware that they previously tended to leave more slack than intended, even when they believed the harness was sufficiently tightened.
Feedback from families also shows that the visual signal can be used as a communication aid with older children, helping them understand the importance of sitting properly during harness tightening.
Overall, the activity has resulted in increased attention to harness tension, greater confidence among caregivers, and improved consistency in harness tightening behaviour. User feedback strongly suggests that eBuckle by Holmbergs™ supports safer everyday use of child car seats by helping translate safety awareness into practical action.
User feedback indicates that the guidance helps caregivers better understand how tight the harness needs to be, increasing confidence when securing their child in the car seat. Several users noted that the eBuckle by Holmbergs™ made them aware that they previously tended to leave more slack than intended, even when they believed the harness was sufficiently tightened.
Feedback from families also shows that the visual signal can be used as a communication aid with older children, helping them understand the importance of sitting properly during harness tightening.
Overall, the activity has resulted in increased attention to harness tension, greater confidence among caregivers, and improved consistency in harness tightening behaviour. User feedback strongly suggests that eBuckle by Holmbergs™ supports safer everyday use of child car seats by helping translate safety awareness into practical action.
Please briefly explain why your initiative is a good example of improving road safety.
eBuckle by Holmbergs™ is a strong example of improving road safety because it addresses a well documented but still widespread risk for infants and toddler: slack in child car seat harnesses. The initiative supports caregivers at the moment of use, when safety critical decisions are made.
Similar support systems are available in vehicles today for adult occupants where the car alert occupants when seat belts are not fastened and some vehicles automatically tighten the seats belts. eBuckle by Holmbergs™ applies the same safety principle to child car seats where the tightening relies entirely on the caregiver.
By guiding and reminding parents to tighten the harness through simple light and sound cues, eBuckle by Holmbergs™ helps reduce unintentional under restraint in everyday situations. This approach acknowledges real world conditions such as time pressure, routine stress, and varying caregiver experience, making safer behaviour easier to achieve consistently.
The initiative complements existing child car seat regulations, education efforts, and safety instructions by translating knowledge into action. Integrated directly into child car seats, it adds safety support without increasing complexity.
Other organisations can learn from this approach, as it demonstrates how safety can be enhanced by adding technology guidance directly into products that are already widely used.
While integrating electronics into child car seat buckles requires technical expertise and testing, the underlying principle is highly transferable. Similar reminder and guidance based safety features could be implemented by manufacturers and safety organisations across different markets. Over time, this type of solution has the potential to become a standard feature that systematically reduces a common misuse and improves child road safety at scale.
Similar support systems are available in vehicles today for adult occupants where the car alert occupants when seat belts are not fastened and some vehicles automatically tighten the seats belts. eBuckle by Holmbergs™ applies the same safety principle to child car seats where the tightening relies entirely on the caregiver.
By guiding and reminding parents to tighten the harness through simple light and sound cues, eBuckle by Holmbergs™ helps reduce unintentional under restraint in everyday situations. This approach acknowledges real world conditions such as time pressure, routine stress, and varying caregiver experience, making safer behaviour easier to achieve consistently.
The initiative complements existing child car seat regulations, education efforts, and safety instructions by translating knowledge into action. Integrated directly into child car seats, it adds safety support without increasing complexity.
Other organisations can learn from this approach, as it demonstrates how safety can be enhanced by adding technology guidance directly into products that are already widely used.
While integrating electronics into child car seat buckles requires technical expertise and testing, the underlying principle is highly transferable. Similar reminder and guidance based safety features could be implemented by manufacturers and safety organisations across different markets. Over time, this type of solution has the potential to become a standard feature that systematically reduces a common misuse and improves child road safety at scale.
How have you shared information about your project and its results?
Information about the eBuckle by Holmbergs™ initiative and its results has been shared through a combination of industry collaboration, user testing activities, and targeted communication channels in social media.
Throughout development and implementation, findings and evaluation results have been shared directly with child car seat manufacturers. In parallel, the initiative has been raised through child car seat ambassadors. These ambassadors are administrators of large parent communities on social media and have shared experiences and reflections.
This peer‑to‑peer communication has helped raise awareness about the issue of slack in harnesses and highlighted practical everyday safety considerations. As a result, the initiative and its approach are becoming known beyond a local context, contributing to wider discussions on child car seat use and road safety across different markets.
Throughout development and implementation, findings and evaluation results have been shared directly with child car seat manufacturers. In parallel, the initiative has been raised through child car seat ambassadors. These ambassadors are administrators of large parent communities on social media and have shared experiences and reflections.
This peer‑to‑peer communication has helped raise awareness about the issue of slack in harnesses and highlighted practical everyday safety considerations. As a result, the initiative and its approach are becoming known beyond a local context, contributing to wider discussions on child car seat use and road safety across different markets.
Supporting materials
