The Insurance Institute for Highway Safety has found that booster seats are doing a poor job of improving the fit of lap and shoulder belts for children.
Booster seats are meant to do one thing — elevate children so that safety belts designed for adults are in the right position to restrain kids during a crash. Thirteen of the 41 belt-positioning booster seats the Institute evaluated with the University of Michigan Transportation Research did so poorly that the Institute doesn’t recommend them at all. Ten models are best bets, and five were good bets.
“We evaluated the safety belt fit boosters provide, not crash protection,” said Institute president Adrian Lund. “This is because unlike child restraints, boosters don’t restrain children in crashes. They simply position children so lap and shoulder belts are in the right place to restrain them.” Good boosters route belts across a child’s bony parts, not soft parts like the abdomen, which is more vulnerable to injury.
“We’d expect the 10 best bets to improve belt fit for children in almost any car, minivan, or SUV,” Lund said. “Likewise, it’s clear that kids in the 13 boosters we don’t recommend aren’t getting the full benefit of improved lap belt fit. These boosters may increase restraint use by making children more comfortable, but they don’t position belts for optimal protection.”
Researchers at the University of Michigan Transportation Research Institute assessed two types of boosters — backless and highback — under conditions representing a range of 2001-06 model vehicles. Some highbacks convert to backless, and some boosters, called combination seats, can be used as child restraints. Highback and backless modes were evaluated separately because each mode affects how belts fit. More importance was assigned to lap belt fit. All of the best-bet boosters locate this belt on children’s upper thighs. The main problem for the boosters that aren’t recommended is they leave the lap belt partially or fully on the abdomen. Fit is important because a correctly positioned lap belt loads pelvic bones during a crash, not the abdomen. A good booster also positions the shoulder belt at midshoulder, keeping the webbing away from the neck so it won’t chafe and reducing the likelihood that kids will endanger themselves by putting the belt behind their back or under an arm.
“Our data show it’s possible to design a booster with good lap and shoulder belt fit,” said Matt Reed, the study’s lead author and research associate professor at the University of Michigan Transportation Research Institute. “Boosters that can’t do that should be redesigned.”
Boosters the Institute doesn’t recommend are the highback Compass B505, Compass B510, Cosco/Dorel Traveler, and Evenflo Big Kid Confidence; backless Safety Angel Ride Ryte; combination Cosco/Dorel Alpha Omega, Cosco/Dorel (Eddie Bauer) Summit, Cosco Highback Booster, Dorel/Safety 1st (Eddie Bauer) Prospect, Evenflo Chase Comfort Touch, Evenflo Generations, Graco CarGo Zephyr, and Safety 1st/Dorel Intera. At least 2 of these models have been discontinued, hopefully replaced by better designs. Booster makers sometimes reuse names and even model numbers for new seats, so manufacture dates and model numbers are important, the Institute said.
Best bets and good bets
The 10 best-bet boosters are the most likely to position not only lap belts but also shoulder portions correctly on many children in many vehicles. Best bets include 3 backless seats: Combi Kobuk, Fisher-Price Safe Voyage, and Graco TurboBooster. These may require plastic clips to correctly position shoulder belts. Six highbacks are best bets: Britax Monarch, Britax Parkway, Fisher-Price Safe Voyage, LaRoche Bros. Teddy Bear, Recaro Young Style, and Volvo booster cushion. Another best bet is the combination seat Safeguard Go when it’s used as a backless booster. Combination seats convert to boosters by removing their built-in harnesses. At least 5 of the best-bet boosters have been discontinued but still are sold.
The five good bets provide acceptable belt fit in almost as many vehicle belt configurations. They are highbacks Combi Kobuk, Graco TurboBooster, and Safety Angel Ride Ryte, and combinations Recaro Young Sport and Safety 1st/Dorel Apex 65, when used as highbacks.
“Boosters that provide better belt fit aren’t necessarily the priciest,” noted Anne McCartt, Institute senior vice president for research. “Parents don’t have to spend a lot of money for a best bet or good bet booster.” The highback Graco Turbo-Booster, for example, converts to a backless booster and retails for about $50. The backless-only version sells for about $20.
Child safety seat laws in 43 states and the District of Columbia include booster seat provisions, but until now there has been little information on how to pick one that provides proper belt fit. The government’s dynamic tests of boosters don’t measure belt fit. Congress in 2002 told the National Highway Traffic Safety Administration to evaluate a belt fit test, but the agency decided to forgo testing. Instead, it only rates boosters by how easy they are to use. Manufacturers crash test boosters, but these simulated tests don’t tell parents how boosters will fit kids in their vehicles.
For more information, visit http://www.iihs.org/sr/pdfs/sr4308.pdf.