Understanding How NHTSA Rates Child Car Seats & Restraints for Ease of Use
At the direction of Congress, National Highway Traffic Safety Administration was charged with establishing a child car safety seat and restraint ease of use (EOU) rating system. As of section 14(g) of the Transportation Recall Enhancement, Accountability, and Documentation (TREAD) Act requires, the rating system was to be designed so to, “provide practicable, readily understandable, and timely information to consumers for use in making informed decisions in the purchase of child restraints.”
Child restraint systems are important for young children because they can reduce the likelihood of a serious injury or death in an automobile accident. Compared to a fully grown adult, children have softer bones, weaker supporting muscles in the neck, and heads that are larger in proportion to their body. A child safety seat is designed to protect a child from these developmental deficiencies by:
- Preventing the child from being ejected or thrown from the vehicle.
- Holding the child in his or her seat in the car, truck or SUV.
- Distributing the force of the impact over a broader area
- Absorbing some of the impact’s force.
However, child restraint systems are only effective when they are installed and utilized properly. NHTSA believed that there was ample consumer confusion regarding the proper use and installation of these safety devices to warrant a program to assess their ease of use. Before we delve further into NHTSA’s CRS ease of use program, it is important to note that all child restraints must also comply with Federal Motor Vehicle Safety Standard (FMVSS) No. 213. While this article will focus on NHTSA’s ease of use rating system, we will revisit FMVSS 213 in the near future.
Child Restraint Systems Ease of Use
The main goal of the EOU program is to provide better and more useful information to consumers seeking to purchase a child restraint system. The program can provide consumers with information about the types of securing technology that exists. The program also raises consumer awareness regarding the importance of proper CRS installation, the steps to properly install a CRS, and the consequences of improper installation. Finally, the program is intended to encourage manufacturers to improve the design and usability of their CRS.
Under NHTSA’s ease of use assessment program, child car restraint systems are rated in rear-facing, forward-facing, and booster seat configurations. The seats are rated based on the ease of use of their instructions, labeling, the physical restraints used, and the installation procedure. An overall ease of use rating is assessed for each category under each configuration. Further, ratings in the number of additional subcategories are also determined in the rating process. Each of the forms referenced in the following sections is available in 73 FR 6261 which is linked to below.
NHTSA’s Approach to Child Restraint Labeling Ease of Use
An EOU rating form has been developed for each area that is assessed in the inquiry. The rating form for Infant Only Restraints, Convertible RF Mode, or 3-in-1 RF Mode, evaluate the quality and clarity of the restraint’s labeling in 6 domains. Ratings of A, B or C is assigned to each subcategory with an A rating signifying good ease of use, a B rating indicating some problems with ease of use, and a C rating generally indicating incomplete information or serious problems with the instruction. For instance, one area of assessment inquires as to whether the labeling shows how to prepare and use the restraint’s lower attachments. The criteria to assess this category includes whether there are clear illustrations that obviate the need for additional explanatory text, the locations of the label or labels, whether the label appears on both sides of the CRS, the label’s contrast, and whether the label is obscured.
Assessing CRS Instruction Ease of Use
The rating form for Infant Only Restraints, Convertible RF Mode, or 3-in-1 RF Mode, evaluates the instruction’s ease of use in 8 areas. One area of concern regarding the sufficiency of the instructions involves whether there is a “Clear indication of a child’s size range. Is there additional information on the CRS about how the child should fit?” The descriptions of the possible ratings are:
- A Rating – “Separate, clear, complete height and weight information directly next to the illustration. Additional size information included alongside a picture.”
- B Rating – “Separate, clear, complete height and weight information directly next to the illustration. Additional size information included as short, simple text.”
- C Rating – “Incomplete text as indicated, text independent or illustration, or no illustration, and/or no mention of additional sizing information.”
Other areas of inquiry regarding the restraint’s ease of use include whether the instruction manual is easy to locate after opening the box, the storage system to access the manual, whether all methods of installation are fully and clearly explained, whether there is a warning against placing a rear-facing seat in front of an airbag, whether the written instructions conflict with product labeling, and several other areas on inquiry.
NHTSA’s Rating of Child Securement Procedures
The ease of the process to actually secure a child in the CRS is also assessed using the same A, B, C rating system. Areas of NHTSA concern regarding the ease of securing a rear-facing child restraint system include:
- Whether all functional parts are already attached and ready to use.
- Whether the harness clip must be threaded to be secured properly.
- The access to & the use of the harness system.
- The number and adjustability of the harness slots.
- The ease of adjusting the harness to accommodate the child’s growth and development
- The ease of converting the seat from rear-facing use to other configurations.
There are a number of other areas assessed by NHTSA regarding the EOU of securing a child in a car restraint system.
NHTSA’s Approach to Vehicle Installation Features
NHTSA assessment for ease of proper installation in a vehicle is also an area of focus. The areas of NHTSA concern include the ease of routing the vehicle belt or LATCH straps, the ease of attaching or removing the seat, whether the anchors require twisting or other manipulations to remove from the base, whether the carrier has an indication of the proper handle placement.
Calculating a Restraint System’s Overall Rating
Aside from the ratings by subcategory that we have previously discussed, each area is also given an overall ease of use rating. Restraint systems are rated from 1 to 5 stars with 1 star signifying the lowest level of ease of use and 5 starts signifying the highest level of ease of use.
The overall rating is assessed by calculating a weighted average of each of the four areas of inquiry. Each subcategory or feature is assigned a point value based on its quality and ease of use. Furthermore, each area is also rated at an integer value from 1 to 3 based upon the risk of injury if misused. For instance, based on the risk of misuse in the securement procedures category, one point is assigned to the “visibility and alignment of harness slots”, two points for “Ease of adjusting/removing shield”, and three points for “Is the seat assembled & ready to use”. A weighted average is computed by multiplying the feature score by its weight. The weighted average computed then corresponds to a star rating. The star ratings are:
- A 1-star rating is assigned to a weighted average of less than 1.70.
- A 2-star rating is assigned to a weighted average greater than 1.70 and less than 2.00.
- A 3-star rating is assigned to a weighted average greater than or equal to 2.00 and less than 2.30.
- A 4-star rating is assigned to a weighted average greater than or equal to 2.30 and less than 2.60.
- A 5-star rating is assigned to a weighted average greater than or equal to 2.60.
The ease of use star ratings is accessible through NHTSA’s website. They are an important tool in assessing the ease of use and the safety of child seat restraints so that a parent or caregiver can make an informed safety decision and, in the event of an accident or collision, reduce the risk of a catastrophic injury or death to his or her child.