Sixteen
three states · three rules · one trip
Washington and Oregon are among the strictest in the country. Idaho is one of the most lenient. When you're crossing state lines, the strictest law applies.
This chapter is short and focused. The PNW spans three states with three different car seat laws, and if you're driving a multi-state route, you need to follow the strictest one. That's almost always Washington or Oregon.
I'm not going to lecture you about safety. You came to a travel guide for a vacation, not a child passenger safety class. But I will give you the actual rules in plain English, plus the practical stuff about flying with car seats and using rideshares.
the three state laws
When you cross state lines, the law of the state you're currently in applies. Your home state's rules don't follow you.
If your trip crosses state lines, the law of whichever state you're currently driving in applies. The safest bet on a multi-state trip is to follow Washington's rules everywhere, since those are the strictest in the region.
Real example: A 7-year-old, 4'2" Idaho kid riding in a regular seat belt is legal in Idaho. The same kid in Oregon needs to be in a booster. Cross the state line, swap setups, or just keep the kid in a booster for the whole trip.
by age & stage
Best-practice safety recommendations, not minimum legal requirements. Most state laws fall behind the latest safety guidance.
| Stage | What it is | When |
|---|---|---|
| Infant (rear-facing) | Infant carrier (typically up to 30-35 lbs) or convertible seat in rear-facing mode. Critical for the head/neck/spine of babies. | Birth to age 2 minimum. Many seats allow rear-facing to 40-50 lbs. |
| Toddler (forward-facing) | Convertible or harnessed seat with 5-point harness. Stay in the harness as long as possible. | Age 2-5 typically. Until child outgrows manufacturer limit (usually 50-65 lbs). |
| Booster (high-back) | Belt-positioning booster with back support. Uses the vehicle's regular seat belt. | Age 4-8 typically. Until the seat belt fits properly without the booster. |
| Booster (backless) | Backless booster (sometimes called a "no-back booster"). Cheaper, easier to travel with. | Age 6+ typically. Only when the vehicle has a headrest behind the child's head. |
| Seat belt only | Regular vehicle seat belt. Must fit properly across hips and shoulder. | When child passes the 5-step seat belt fit test, usually age 8-12. |
The honest measure of whether your kid is done with a booster. Both states use a version of this test for booster exit.
1. Does the child's back rest flat against the vehicle seat?
2. Do the child's knees bend comfortably over the edge of the seat?
3. Does the shoulder belt lay flat across the chest and collarbone (not the neck)?
4. Does the lap belt lay low across the upper thighs (not the stomach)?
5. Can the child stay seated like this for the whole trip without slouching?
If you can't answer YES to all five, the kid still needs a booster, regardless of age.
rental cars & car seats
Pros: You know the seat is clean, properly installed, and your kid is comfortable in it. Free at most airlines as checked luggage or carried on a plane seat. The safest and usually cheapest option.
Cons: Bulky, awkward to carry through the airport. Risk of damage from baggage handlers.
Tip: Use a padded car seat travel bag ($30-$60). Tag the bag with your contact info. Check the seat at the gate or as checked luggage, not in the overhead bin.
Pros: Nothing extra to carry. Just shows up with the car.
Cons: $13-$17/day per seat, capped around $90-$130 per rental. Can add up fast for a multi-week trip. Quality varies wildly. Some rental car seats are visibly old, dirty, or missing parts.
Tip: If you go this route, inspect the seat thoroughly at pickup. Check the expiration date (printed on the side or back). Most car seats expire 6-10 years after manufacture. An expired seat is a useless seat in a crash.
For kids 4+ years old who only need a booster (not a full harness seat), this can be the smart move. A backless booster at Walmart or Target runs $15-$25. Buy it on day 1, donate it on day 14.
Doesn't work for younger kids who need a full harness seat. And buying a brand-new harness seat just for a trip is a waste of money.
Companies like BabyQuip rent quality car seats locally. Roughly $7-$10/day, delivered to your hotel or rental, picked up at the end. Cleaner and newer than rental car company seats. Available in Seattle, Portland, and most major PNW cities.
For trips with kids under 5: fly with our own seats. The peace of mind is worth the airport hassle, and the seats are free as checked baggage at every major airline.
For trips with kids 5-8 who only need boosters: buy a $25 backless booster at the destination. No airport hassle, no rental car upcharge, and we donate the booster at the end of the trip or pass it to family in the area.
For older kids: just bring the seat belt fit test in your head and verify the belt fits properly in the rental car.
uber, lyft, taxis
This is the question I get asked most about. The honest answer: Oregon, Washington, and Idaho all require child restraints in Ubers and Lyfts the same as any private vehicle.
Uber and Lyft do not provide car seats in the PNW (unlike in some cities where Uber Car Seat is available). You're responsible for bringing your own.
A backless booster for kids 4+ is the easiest travel-with car seat. Folds flat in a tote bag, weighs 2-3 lbs. Toss it in your day bag, take it in the Uber, no setup.
A travel-specific harness vest like the RideSafer (legal in WA and OR). Folds up small, easier to travel with than a hard-shell seat. Approved as a car seat alternative in both states. Pricey ($170-$240) but worth it for families who do a lot of rideshare.
For infants or kids under 2: You need a real car seat. Bring the infant carrier with you for the whole trip, or skip rideshare entirely with the youngest kids. Public transit is often easier with babies anyway.
For airport-to-hotel rides with kids under 4: book a rental car at the airport instead. Or take the light rail (Portland's MAX, Seattle's Link). Bringing a car seat to an Uber from baggage claim is a special kind of stressful.
For day trips around town with kids in boosters: backless booster in a tote bag works. Easy in, easy out.
other safety stuff
All three PNW states are primary enforcement for adult seat belts, meaning an officer can pull you over for nothing else if a passenger isn't wearing one. Don't be the family that gets a ticket on vacation for $124 because Dad's seat belt was off in the back seat. Buckle up, every seat, every time.
All three states have hands-free laws. No handheld phone use while driving. Bluetooth, Apple CarPlay, Android Auto are fine. The fines are real: Oregon $265 (Class B, up to $1,000 max, waivable with a distraction-avoidance course), Washington $136, Idaho $75 first offense. Texting while driving is enhanced penalty everywhere.
0.08% BAC limit in all three states. Drunk driving in a national park (or anywhere on federal land) is a federal offense with separate penalties. Time is the only thing that lowers your BAC, nothing at the bar speeds it up. If there's any question, call a rideshare or wait it out.
I know this isn't car seat content, but I'm putting it here because it's the safety question second-time-PNW-visitors ask me most. Black bears are present throughout the PNW. Olympic, Cascades, Rainier, Crater Lake, all of Idaho. Grizzlies live only in the North Cascades and the Idaho panhandle.
Three rules: (1) Store food in a hard-sided cooler in the car, never in tents. (2) Don't leave food, sunscreen, or scented items in your tent or in plain sight in the car at trailheads. (3) If you see a bear, make yourself big, make noise, back away slowly. Do not run.
Most bear encounters in the PNW happen at picnic spots and campgrounds, not on trails. The bears are habituated to human food. Don't be the person who teaches the next bear that humans = food.
Pacific Coast tides have killed people. Specifically the sneaker waves on Oregon Coast that come up the beach far higher than normal. The "watch for falling driftwood" signs at Oregon beaches are real.
Rules: Never turn your back to the ocean on the Oregon Coast. Check tide tables before walking past a tide pool. The 2 hours before and 2 hours after low tide are safe. The 2 hours before high tide can be deadly on certain beaches (Cape Kiwanda, Hug Point, the headlands).
The PNW is wetter and colder than visitors expect, even in summer. A wet kid at Hurricane Ridge in July can hypothermic in 30 minutes. Always have a dry change of clothes in the car. Always pack a warm layer, even when the forecast says 75 and sunny.