However, many child restraint manufacturers advertise that they have tested their products in side impact using internal test procedures. US child restraint products currently do not have to be tested under side impact loading conditions. Near-side impacts are most injurious, and the occupant motions involve the child restraint moving toward the door as the door is intruding from the striking vehicle. In near-side events, use of the seat belt is less of a factor in the crash injury outcomes. When the occupant is positioned on the side of the vehicle closest to the striking vehicle it is called a вЂњnear-sideвЂќ impact event and injuries are often caused by direct loading between the striking object and the occupant. If the occupant is on the opposite side of the vehicle from the striking object it is called the вЂњfar-sideвЂќ impact condition and a seat belt can play an important role in the outcome by limiting the possibility of occupant contact. Vehicle-to-vehicle side impact events are often described based on the occupantвЂ™s position relative to the striking vehicle. The lower anchorages must either be visible or labeled, but there are no labeling requirements for tethers. Other requirements for lower anchorages include specifications for the size and spacing of the anchor bars that comprise the lower anchorages, and requirements for how a child restraint fixture must fit in the vehicle when attached to the lower anchorages.

The regulation defines zones for locating the lower and tether anchorages, as well as quasi-static (or slow loading) testing procedures for evaluating the strength of the lower and top tether anchorages. Most vehicles have the minimum required LATCH hardware where top tether anchorages are provided in three seating positions and lower anchorages are provided in two seating positions. Requirements for LATCH hardware in vehicles are specified in FMVSS 225 ( CFR FMVSS 225). Tests are also performed to determine whether the child would stay within the restraint when it is inverted. Other 213 requirements focus on webbing strength, width, and abrasion resistance, flammability of the components, buckle release characteristics, and padding requirements.

Unfortunately, better scores on the head injury criteria can usually be achieved by allowing more head excursion, although keeping the head from moving further forward corresponds to preventing the most common real-world head injury mechanism of the childвЂ™s head striking something in the vehicle ( Bohman et al. In addition, there are limits on head and chest acceleration-based measures. For forward-facing restraints and booster seats, the dummyвЂ™s head must not move forward past a point 720 mm (28.4 inches) from a seat reference point when tested with a tether or 813 mm (32 inches) when tested without a tether in either condition, the knees must not pass a point 915 mm (36 inches) away. For rear-facing restraints, a restraint will pass if the surface supporting the crash dummyвЂ™s back does not rotate forward beyond an angle of 70В°, the head and chest of the dummy stay in the restraint, and the acceleration characteristics for the dummyвЂ™s head and chest do not exceed prescribed thresholds. For a car bed, the primary criterion is that the harness must keep the newborn size dummy in the restraint. When evaluating the dynamic safety performance of a child restraint, requirements vary with the type of restraint.

At first glance, a 30-mi/hr (48 km/hr) test may not seem very severe, but 30 mi/hr (48 km/hr) refers to the change in velocity, not the velocity at the time of the crash, and the crash conditions used are more severe than 96% of actual frontal crashes in the United States.

Sled tests are used because they are more repeatable and less expensive. Child restraints are not crash tested in real vehicles, but tested using a sled that simulates the acceleration seen in a crash with a 30 mi/hr (48 km/hr) change in velocity. In addition, though vehicle seats, LATCH anchorage locations, and seatbelt geometry vary widely in vehicles, child restraints are tested on a generic, soft, flat, bench seat using either a single set of belt anchorages or LATCH anchorages. Given the high level of occupant protection provided by current child restraints in all types of crashes, people are often surprised to find that the testing requirements as defined in the applicable federal rule, FMVSS 213, primarily focus on their performance in frontal crashes at one severity level (CFR, FMVSS 213).

Fmvss 213 child restraint systems