The Plus Test
The Plus Test is a voluntary test of a child car seat with focus on neck protection of the child and overall robust protection in a frontal impact. Rearward facing child car seat provides the best protection for the child, which is why the Plus Test is only performed on rearward facing car seats.
The Plus Test is executed as a sled crash test representing a high severity frontal impact, in which the neck load is measured and evaluated, in addition to overall child occupant protection. If the child car seat passes the test, a Plus Test label is awarded, and the seat is listed at Plus Tested models providing evidence of a robust and safe rearward facing child car seat.
The current revision (2023) follows on the updates of the test bench and crash test dummies introduced in R129.
The Plus Test was launched in 2007 following the Swedish tradition of addressing protection of the neck for small children in type-approval of child car seats, evaluated in the former Swedish “T-test”. After joining the European Union, the “T-test” was withdrawn and replaced by the UN ECE type-approval. The child car seat type-approval by UN ECE Regulation no. 44 (R44), followed by Regulation no. 129 (R129), do not include evaluation of neck loads. Neck protection is the main protective concern for small children, up to at least 4 years of age.
The Plus Test was initiated and developed by SIS/TK242 (Standardutveckling - Barnsäkerhet i bil SIS/TK 242 - Svenska institutet för standarder, SIS External link. ) and is executed by VTI.
Advantages of rearward facing child car seats
Real-world experiences provide evidence of superior child occupant protection in rearward facing child car seats. A rearward facing seat effectively limits the loads through the neck in a frontal impact, which is the most severe and common crash type. It also provides an overall robust protection in real-world crashes, through its distributed and supportive design and its relative insensitivity for variations in attachments and adjustments. For many years, rearward facing child car seat for toddlers were only available on the Nordic markets.
Recently, a positive global increase of rearward facing child car seat use for toddlers is seen. However, these child car seat mostly also allow use in a forward facing mode, so called convertible seats.
Based on the real-world evidence of rearward facing protection for children up to at least 4 years of age, the Plus Test aims to help consumers choose the most robust and safe child car seat for this age group.
The crash test
The Plus Test is a voluntary frontal impact test of a child car seat with focus on neck protection of the child and overall robust protection. If passed, a label will be awarded helping consumers to understand that the child car seat has passed this demanding test.
The Plus Test was launched in 2007 following the Swedish tradition of addressing neck protection for children in type-approval of child car seats. This was previously evaluated in the former Swedish “T-test”. After joining the European Union, the “T-test” was replaced by the UN ECE type-approval, which does not evaluate neck loads.
UN ECE R44 and R129 are mandatory type-approval of child car seats, while the Plus Test is a voluntary complement. The Plus Test evaluates neck protection in a high severity frontal impact test.
The UN ECE R129 and R44 include several tests and other assessments. The Plus Test includes one type of test only, which is a frontal impact. Except for the crash test severity, most of the test setup for the Plus Test is similar to the frontal impact test in UN ECE R129. While UN ECE R129 includes testing in multiple seat adjustments and crash test dummy sizes, the Plus Test includes one test only.
Not all types of child car seats are eligible to apply for the Plus Test. The Plus Test is dedicated for toddler seats for rearward facing use, only. The child car seat must have been approved according to R129 range up to 125 cm or R44 groups I or II.
Substantive real-world experience provides evidence of superior protection in rearward facing child car seat for toddlers. The Plus Test aims to help consumers choose the most robust and safe child car seat for this age group.
The Q3 and Q6 crash test dummies are used, representing a 3- and a 6-year-old child, respectively. The Q-series dummies are the latest and most advanced child crash test dummies.
Any built-in or add-on activation functions of the child car seat, such as for activating an airbag, shall be disabled prior to test. This is irrespectively if recommended by manufacturer or not.
The Plus Test addresses overall robust protection in real-world crashes. Real-world crashes may include multiple impacts, whereby built-in or add-on features requiring activation may have reduced effect, in addition to the limited assessment possibilities ensuring activation in a large range of situations. This applies to all activation functions, except those that are mechanical functions built into the child car seat which cannot be disabled due to their design. Examples of such mechanical functions given they provide robust performance are load limiting devices with predicted and reproducible behavior and defined as such in the manufacturer’s technical description.
The crash severity of the Plus Test is one of the toughest on the market for child car seat assessment. The crash test pulse represents a frontal impact of roughly 56 km/h, while the corresponding speed in the type-approval test is approximately 50 km/h. In addition, the crash pulse magnitude is higher, representing a shorter stopping distance, i.e., a harsher deceleration during the impact, resulting in much higher crash energy induced to the child car seat.
The current revision (2023) follows the principles of the prior versions. Updates to test bench and crash test dummies are done in line with the introduction of R129. In addition to evaluating neck loads, aspects on robustness are now specified more clearly as part of the assessment. The purpose of the test is to promote rearward facing protection for children up to at least 4 years based on the real-world evidence. With a strengthened emphasis on pure rearward facing seats, the Plus Test aims to help consumers choose the most robust and safe rearward facing child car seat for this age group.
The same safety principles apply. The main purpose is to evaluate the neck protection and robust real-world protection in high severity frontal impacts, which is important for children’s safety.
All tests for the Plus Test are executed at VTI’s crash test facility in Linköping, Sweden.
In addition to the neck load, robustness is included in the Plus Test as part of the evaluation. In the 2023 revision, the specification of robustness is improved. The robustness criteria include retention of the crash test dummy and the child car seat in addition to restricting separations or breakage.
All Plus Tested child car seats have undergone and passed the type-approval tests, providing an overall fundament of the child car seat robustness and performance.
With a relatively large head and weak neck, the vulnerability of the head and neck requires good support, which is reflected in neck load measurements. The crash test dummy is equipped with a neck sensor and the measured forces need to remain under a certain predetermined limit. Neck load is not evaluated in R44 nor R129. The Plus Test contributes with this information, which is essential for the child’s protection.
The crash test dummy can measure several measures, however the neck is the main focus for protection of small children.
Plus Tested child car seats
Yes! A child car seat awarded the Plus Test has passed one of the toughest child car seat tests in the world. A relatively small number of child car seats have been awarded the Plus Test label since the start in 2007.
The Plus Test is a voluntary test and reports only those awarded. There are several potential reasons for not being awarded a Plus Test label, such as not being eligible to apply, not applying for the test, or due to failing the test for different reasons. Up to date relatively few child car seats have been awarded. They all include the protective capacity needed for neck protection in frontal impacts.
The purpose of the Plus Test is to evaluate whether the head is provided robust support by the child car seat, to help reduce relative movements between the head and torso in a frontal impact. We don’t see an added benefit of ranking the degree of this support.
No, the different categories reflect the range of children for which the child car seat is type-approved for.
No. No additional tests are required due to the revision. The previously awarded Plus Test label is still valid. However, repeated testing according to Conformity of Production (COP) still applies.
Real-world experiences provide evidence of superior child occupant protection in rearward facing child car seats. A rearward facing seat effectively limits the load through the neck in a frontal impact, which is the most severe and common crash type. It also provides an overall robust protection in real-world crashes, through its supportive design and its relative insensitivity for variations in attachments and adjustments.
A rearward facing child car seat distributes the loads over the back of the child supporting the head and body evenly thanks to the child car seat structure. In a forward facing child car seat the child’s body is restrained by the harness while the head is mainly restrained by the neck. In case of slack in the harness or the seat attachments, neck loads will increase for the child in the forward facing seat, while not have any major influence on the child’s neck in the rearward facing seat.
The Swedish recommendation for children is to remain rearward facing until at least age four, but preferably longer. Reason for this recommendation are the safety benefits of travelling rearward facing, especially for the smallest children. Development of rearward facing child car seats have steadily progressed providing compact seats with high backrest. A number of child car seats allow for a high weight limit and comfortable rearward facing use to 7+ years.
A rearward facing child car seat provides superior protection in real-world crashes thanks to their supportive and robust design. The supportive effect of the child car seat structure helps to keep the neck loads very low. This is beneficial in frontal impacts, in addition to side impacts and complex crashes including multiple impacts and rollovers. In all forward facing seats, irrespectively if using an internal harness, shield or the vehicle’s seatbelt, the restraint for the head is the child’s neck in frontal impacts. In addition, the child’s head is more exposed in side impacts and complex events, as compared to when rearward facing. A rearward facing child car seat is also more forgiving for potential misuse and slack in attachments and adjustments.
Sweden has a unique position in child safety. Child safety in cars started in Sweden and it started with rearward facing child car seats. Introduced 1967, rearward facing child car seats have been used as the primary seat for small children (up to 7-year-olds initially). In 1978 booster seats were introduced (also a Swedish invention), and there has never been a need for other types of child car seats, such as forward facing harnessed seats. During all these years, all stakeholders in Sweden have worked together, aligned and actively communicated the benefits of rearward facing child car seats. Real-world data supports the superior safety for children in cars in Sweden.
The information is in Swedish: