One of your car’s most important safety items is also its most simple: a belt across your hips and chest. In a serious crash, you can double your chances of survival just by wearing your seatbelt.

But there’s quite a history to that belt, and a surprising amount of controversy as well.

The earliest belts were intended for horse-drawn wagons, although it’s not clear how many actually made it to market. One of the first was patented on February 26, 1895, when Philip Schwarzmiller of Rochester, New York came up with his “Child’s Guard for Vehicle Seats.” His intention was that the child could safely sit without being held by a parent.

Some sources mention an even older “safety belt” design from 1885, but it was snapped onto something like a ladder, similar to the safety harnesses that construction workers use today.

Early airplane pilots were the first to use seatbelts. Race driver Barney Oldfield saw merit in them, and in 1922, asked parachute manufacturer Leslie Leroy Irvin to make him a harness for his car. Irvin used the idea to jump-start a new seatbelt company that’s still around today.

By the 1930s, seatbelts were offered by several aftermarket companies, and some doctors’ associations urged automakers to offer them as original equipment. That didn’t happen until 1950 though, when two Nash models became the first American-built cars available with built in belts. Six years later, Ford and Chrysler also offered lap belts in some cars. Still, the vast majority of vehicles from all automakers left the assembly lines without them.

Volvo had diagonal seatbelts, but the buckles were placed in such a way that the belts themselves could cause injury. When a relative of Volvo’s president died in a crash while wearing one, a better design had to be created.

That task went to Nils Bohlin. He’d joined Volvo as a safety engineer in 1958, after working on ejection seats for an aircraft manufacturer. He knew that a lap belt, while better than nothing, was inferior to a combination of one belt over the hips, and another over the shoulder and chest. But it had to be easy to use, which meant it had to close with only one buckle.

He came up with the design for the three-point, one-buckle system that’s still used today. But there was an unusual twist when the company applied for its patent—an open patent. The belt design was considered so important for occupant safety, Volvo made it available for any automaker to use.

The belts became standard equipment on the 1959 Volvo 120 and PV544 models sold in Sweden, and were introduced on cars sold globally, including in North America, in 1963. But even Swedish drivers complained that they found the belts awkward and didn’t want to wear them.

Some seatbelts want to get up-close and personal with you. Some will lock in place if you lean forward too quickly. Others use a little electric motor that momentarily snugs the seatbelt and then cuts you a bit of slack. It can be really annoying, but there’s a reason for it – it’s measuring you in case its pretensioner has to go off.

A pretensioner uses an electro-mechanical or pyrotechnical device to tighten the belt in a crash, where you can face two potential dangers if your seatbelt is too loose. You can be thrown forward far enough in a crash that the deploying airbag can harm you, or you might slip under the belt, known as “submarining,” which can cause severe injuries. Mercedes-Benz was the first to use them in its 1981 S-Class.

Belts that tug now know how tight they have to be if you smack into something. And if you do, the pretensioner reels in the slack almost instantly, pulling you back into the seat and – you hope – out of harm’s way. Just as with an airbag, pyrotechnic pretensioners are single-use only, and must be replaced if the vehicle’s fixed after a crash.

Seatbelts also have load limiters that do the opposite: if necessary, they’ll give way slightly, so you’re less likely to be harmed by the belt itself. While neither pretensioners nor load limiters have ever been required by law, they’re now in the front seats of virtually all vehicles.

The U.S. government passed laws in 1963 setting standards for seatbelt strength and testing, and by 1964, about half of the states required new cars to have lap belts on the outboard front seats. However, no law stated that anyone actually had to use them.

The first jurisdiction to actually enforce the use of seatbelts was Victoria, Australia in 1970, which required occupants in both the front and rear seats to wear them. A few more countries had passed seatbelt laws by 1972.

Oddly enough, Sweden didn’t pass its seatbelt law until 1975, and only front-seat passengers over the age of 15 had to wear them.

The first Canadian province to require their use was Ontario, on January 1, 1976. Quebec followed in August of that year. Passing its law in 1991, the Yukon was the last to sign on.

All of Canada’s seatbelt laws are primary, meaning you can be pulled over solely for not wearing one. But in the U.S., only 33 states and the District of Columbia have primary laws for front-seat occupants. In 16 states, it’s a secondary law, and you can only be given a seatbelt ticket after you’ve been pulled over for another traffic offence. New Hampshire—the “Live Free or Die” state, according to the slogan on its license plates—still does not require adults to wear seatbelts.

Passenger safety has further improved with the adoption of the airbag, although that took quite a while, too. Since so many drivers refused to buckle up, many regulators initially pushed for airbag legislation in place of stronger seatbelt laws, figuring the bags would save people who weren’t wearing their belts. But it wasn’t long before everyone discovered that airbags are dangerous or even deadly without seatbelts, which keep people in the ideal position for the airbag to be effective.

And while Bohlin’s original design is still the basis of seatbelts today, there have been innovations. Some cars have pretensioners, which tighten the belt on impact for better protection. Ford even has inflatable belts containing small airbags, which spread the crash force across the body to prevent chest injury, especially in children and elderly adults. And there’s no doubt that other improvements to that basic design will eventually be here.