Car Seats

March 5th, 2013 by Potato

We bought the Graco Snugride 35 carseat initially because all the safety research suggests that keeping kids rear-facing longer is safer. Rated up to 35 lbs, we figured that this car seat — though large and heavy — would keep Blueberry rear-facing until she was pretty much two years old. Though it’s large for an infant carrier, I was able to fit it in the Prius and still manage to get my seat to a decent position for driving (it’s about an inch further forward than I had it when I positioned my seat without any such constraints — not the most comfortable position but a workable compromise). Blueberry is very tall for her age (obviously a mix-up at the hospital), and though she still has over 10 lbs to go before hitting the weight limit she’s getting close to the maximum height for her infant seat. Time to move up.

So now we’re off shopping for convertible car seats, the next step up that can be either rear- or forward-facing. With these larger seats, it’s almost impossible to find ones that can fit behind a front seat well enough for me to drive or for Wayfare to comfortably sit. I’ve been checking various forums for tips and reviews and pictures of how they fit, and it seems like the two on our shortlist are the Britax Marathon/Boulevard or the Diono Radian. I’ll spare you my pro/con lists, coin-flipping, and hand-wringing on this decision (though feedback on those seats is welcome in the comments).

What really got me in our search was the oft-stated fact that carseats are improperly installed some huge portion of the time. I heard numbers ranging from 80% to 95% depending on the source, and it got me thinking: where does this bit of conventional wisdom come from? I’ll grant that installing the old-fashioned way with a seatbelt is difficult both in terms of skill and strength required, but I really had no issues with the LATCH install. After all, that’s what LATCH is supposed to help with. Plus, the epidemiology data all says that kids in car seats are safer, so either the install error-rate is over-stated, far more people are managing to get/pay for a professional installation, or seats are safe even if installed incorrectly. I started to wonder just how true this conventional wisdom was, or if perhaps this factiod had been invented by the stores offering a $25 installation service and picked up by the media, so I went off in search of a source.

There are some NHTSA reports that seem to be the origin of these figures. This one, for instance, gives a high error rate for installation, topping 95% for first-time installers, who in this study (or a similar one I just read) were recruited from a university’s volunteer pool (i.e.: first-year psych students giving their very minimum effort for $10 and a course credit).

The most common error is loose installation: a carseat, when properly installed, is supposed to be able to move less than an inch. Now, a carseat that can be wiggled an inch and a half is not meaningfully more dangerous than one that can only be wiggled an inch; likewise, the carrying handle for a removable carseat has a specified position for use in the car for each brand (and it is often different for each model) — though many first-time installers got it wrong, it’s also not usually critical. If they apply a severity score, then “only” about 30% of seats were incorrectly installed in a really bad way. The good news: the error rate drops in half once parents/caregivers who have carseat experience are tested, rather than novices. The bad news: that’s still a nearly 50% error rate. To pick out one more interesting factoid, there was a higher error rate for those who drove cars with leather seats.

I’m surprised that even digging into the data, the “legitimate” error rate still appears to be shockingly double-digits high. That really says that something needs to be done to make carseats easier to install safely. Some kind of standardization is most likely the answer: either continue with LATCH but standardize the connectors, or create a universal base that the manufacturer’s individual seats can clip into. Angle adjusters with a wide range of motion are also likely going to be needed — far too many official installation instructions include the use of towels or pool noodles (sold separately) to prop up one part of the base, which is frankly ridiculous. Many require a great deal of strength to tighten properly, or that the adult put their full weight on the seat to jam it down into position — a ratcheting belt-tightener would be a great feature on many of these seats.

As an aside (and not necessarily a product recommendation) this car seat is a neat one from a human factors point of view, with sensors and a display to help ensure correct installation. The video there is only about a minute long if you want to go have a watch.

4 Responses to “Car Seats”

  1. Jenn Says:

    We have the britax marathon and have been quite happy with it. We will likely get the radian for the new kid when she needs to move up (would love to see your pro/con lists!).
    I couldn’t agree more on the need for standardizing and simplifying installation. It would be great for peace of mind should any one other than me need to install a carseat and drive with my kids.

  2. Potato Says:

    Hi Jenn, in brief, the pro/con list is:


    Continuously, easily adjustable strap height. True, there would only be 3-4 occasions where we would have to take the car seat out and re-thread the straps as she grows, but it’s such a pain in the butt that even avoiding it a few times is a perk worth listing.
    An easier-to-use LATCH connector. Should make the Britax easier to install/reinstall than the Radian, which would be nice if we move the carseat into the grandparents’ cars from time to time.
    Easier to clean fabric.
    Visually more side protection (though the crash test ratings appear to end up the same).

    The major advantage is that it turns into a booster, along with a higher weight limit (100 lbs), so we don’t have to buy another.
    Narrower, so it’s more likely we can fit two more people in the back if needed. Also supposed to be narrow enough to go in the middle and fit between the two front seats (though no LATCH there).
    Folds up smaller for packing on an airplane.
    But, requires this weird little block of foam to sit under it to adjust the angle for rear-facing, which seems chintzy and less safe.

  3. Potato Says:

    An an update:

    We bought both the Britax Marathon and the Diono Radian 100, with the intention of returning one to the store. This way we could do a head-to-head comparison in the car.

    They both had similar LATCH connectors. The Britax was slightly easier because its loops stayed in place, rather than needed to be re-threaded/stored.

    For fit, the Britax was a clear winner: even with a textbook the same size as their “angle adjuster,” the Radian would not fit behind my driver’s seat in any way that would let me drive, and would make Wayfare (at 5’2″) hit her knees on the dash. The limiting point was that the top of the Radian hit the headrest of the seat in front, so putting it in the middle position (where only a seatbelt attachment would work) meant my driver’s seat would fit where it is with the current Graco Snugride 35 or with the Britax, and Wayfare would get about 2″ more legroom (to the same seat positioning).

    The Radian was easier for getting Blueberry in and out: it’s lower, and the more open sides make for a lot more baby maneuvering room. I bonked her head at least once in the testing, and I’m bound to do it more with the Britax in practice. Also since it’s a larger seat, she has more legroom with the Radian.

    In the end, despite the many advantages of the Radian, we decided on the Britax Marathon for the fit. It simply seems like it’s going to be too much of a pain in the butt for Wayfare to give up her ability to recline and nap in the car (or recline and reach over to baby) for the next year or two that Blueberry will spend rear-facing in the carseat.

  4. jenn Says:

    Thanks for the updates, very useful! We liked that the radian is more narrow and may have to go that route for the truck, but I’m sure you’ll be happy with the britax.