In an effort to make child seats easier to install correctly, they're being outfitted with new attachments, either rigid or flexible, that connect directly to special anchors in new cars. This makes installation simpler than before, but Institute evaluations of some child seats with the new attachments show the designs being offered aren't easy to use in all cars with new anchors.
The anchors already are appearing in many new cars, but only a few available child seats have the corresponding attachments. Cosco and Fisher-Price have such models for sale now, and Britax will offer one by April.
How these three restraints compare
The Institute tried installing the two available models, Cosco Triad and Fisher-Price Safe Embrace II, in 13 cars with anchors to see how well the new attachments work. Each model is a convertible restraint that can be used in either rear-facing (infant) or forward-facing (toddler) mode. Each has flexible strap connectors. For comparison, the Institute also tried installing Volkswagen's Bobsy G1 Isofix, a toddler seat manufactured by Britax but not available in the United States.
Rigid attachments on this child seat from Britax allowed a secure fit every time.
Flexible strap attachments on these child seats made by Fisher-Price (left) and Cosco didn't always allow for secure installation.
The rigid connectors built into the underside of the Bobsy G1 facilitated perfect installation in every vehicle. The flexible attachments on the Cosco and Fisher-Price models generally worked well, but under some circumstances in certain cars they didn't install correctly. They also weren't as easy to use as the rigid connectors on the Bobsy G1.
The Cosco Triad couldn't be securely installed as a forward-facing restraint in a few vehicles. In one of the rear seats in the Mitsubishi Montero and in both rear seats of the BMW X5 and Mercedes C class (2001 models), the Triad's attachment straps couldn't be tightened enough to keep the seat from moving more than an inch when pushed or pulled. That's unacceptable according to National Highway Traffic Safety Administration guidelines.
The Fisher-Price Safe Embrace II couldn't be securely installed in the rear-facing mode in more than half of the 13 vehicles, including the 1999 Volkswagen New Beetle and 2001 models of the BMW X5, Dodge Caravan, Dodge Stratus, Honda Civic, Hyundai Elantra, Lexus LS 430, and Mercedes C class. The problem is that the buckles on the attachment straps bind up on the restraint frame, preventing the straps from being fully tightened.
"What we learned is that child seat manufacturers, at least in the United States, aren't yet offering anchor attachments that accommodate all the seating and anchor differences among cars," explains Susan Ferguson, Institute senior vice president for research.
The dimensions and placement of anchors in vehicles are standardized, but the regulations permit slight differences. For example, the 2001 Mercedes C class has retractable anchors that fold out from the seat. Other characteristics that affect the fit of child restraints, such as seat geometry and cushion stiffness, also vary among cars.
What new federal rules require
Starting September 1, 2002, regulations will require all new passenger vehicles to come with 6 mm metal bars in the folds of rear seats to anchor child restraints (see "Car seat anxiety," Jan. 16, 1999). In vehicles without rear seats and with airbag on/off switches, the anchors will be in the front passenger seat.
By the same date, all new child restraints will be required to have latch attachments that connect to the anchors. Child seat makers can design the attachments in either of two ways — as rigid metal connectors or as flexible strap connectors, much like adult safety belts with hooks or buckles at the end.
Tether anchors, the other component of the new anchorage systems, have been required in new passenger cars since 1999 and in light trucks since 2000. Located either on the parcel shelf or on the floor behind the seat, a tether anchor provides a way to secure the upper part of a child restraint. Forward-facing restraints now generally come with top tethers to meet the requirements of dynamic tests, although a tether isn't specifically required.
Taking the easiest route
Car seat makers may be choosing to go with flexible attachments because, unlike rigid systems, "the flexible straps can be added to the child seats already being marketed. Little or no fundamental design changes are required," Ferguson says.
For example, the new Cosco and Fisher-Price seats are virtually identical to previous models except for the addition of flexible anchor straps. Sometime this year, Century Brand plans to offer an add-on kit so existing models can be retrofitted with flexible attachments. Graco also will add flexible attachments to some of its models.
The rigid attachment system on the Volkswagen Bobsy G1 is fundamentally different from conventional models. The metal hardware adds weight and cost, but installation is simple. When the restraint is pushed back into the seat, the brackets latch onto the anchors and easily adjust for a snug fit.
"It remains to be seen what the child seat makers will offer later, but right now the flexible anchor attachments haven't been perfected," Ferguson adds. "They still have a long way to go before parents have a foolproof means of correctly installing child seats in all cars."