Car Tech

The Surprising Origins of Common Safety Features

From their earliest days as motorized buggies with tillers for steering them, cars have evolved into complex machines. While most of their innovations were developed over years of tweaking with what was already there, there are a few items on your car today that can be traced back to a single episode – and here are some of them.

TPMS – Ford and Firestone fight it out

The tire-pressure monitoring system, or TPMS, uses sensors to warn if a tire drops below the recommended amount of air that should be inside. It’s mandatory on all new cars sold in the United States as a requirement of the TREAD Act (Transportation Recall Enhancement, Accountability and Documentation) passed in November 2000, itself a direct result of a scandal involving Ford and Firestone.

Earlier that year, the National Highway Transportation Safety Administration (NHTSA) began looking into a string of fatal rollover crashes of Ford Explorers with factory-equipped Firestone tires. The two companies pointed fingers at each other, but it was ultimately determined that Ford had specified lighter-weight tires for fuel economy and a lower recommended pressure for ride quality, which Firestone provided and which proved disastrous when drivers didn’t check their pressure regularly and they got even softer.

Almost 20 million tires were recalled, the automaker and tire company ended their 95-year relationship, and cars started getting tire-pressure warning lights. The recall costs were enough of a strain on Firestone’s finances that it agreed to a takeover by Bridgestone. TPMS is still not mandatory in Canada, although it’s standard or available on most models sold here today.

Airbags… and Torpedoes

In 1952, retired engineer John Hetrick was driving in Pennsylvania when he narrowly avoided a crash. There were no seatbelts in his 1948 Chrysler, and he instinctively put his hand on his young daughter to keep her from flying forward into the dash. That started him thinking of a device to provide similar – and far more effective – protection.

During his time in the Navy, he’d seen fabric torpedo covers fly off with air compression. Building on that, he came up with an inflatable fabric bag that would keep front-seat occupants from hitting the dash or windshield.

Hetrick patented his idea in 1953, but he wasn’t the only one. That same year, German inventor Walter Linderer also got a patent for a similar device. But neither could come up with a way to effectively deploy them – Linderer suggested drivers hit a switch if they thought they were going to crash – and the bags stayed in limbo until 1968, when American engineer Allen Breed invented a reliable crash sensor. GM briefly offered optional airbags in the 1970s, while Porsche made two front bags standard in the 1987 944 Turbo, the first car sold in the US so equipped.

Interestingly, while airbags have been mandatory on all new cars sold in the US since model-year 1999, that’s not been the case in Canada. Instead, Ottawa sets a front-seat occupant safety standard. Automakers could use anything that meets it, but since airbags do and they’re already engineered into vehicles for the larger American market, that’s what we get.

Check Engine Light – It’s all about the tailpipe

Ignored on dashboards across the nation, the dreaded “check engine” light arrived as a result of the US government mandating OBD-II, or second-generation on-board diagnostics system, for all new cars and light trucks on January 1, 1996, in keeping with pollution standards.

Anti-smog regulations started in California and were picked up by the federal government, which set nationwide standards for vehicle emissions. But it isn’t enough to just sell the car with lower levels of pollution coming out the back – the vehicle has to maintain that status throughout its life. If something goes wonky and emissions exceed the allowable threshold, the OBD-II system illuminates the check engine light, telling the driver that a trip to the shop is required.

The Self-Starter – From a broken jaw

Early cars had to be cranked to start them, which could be difficult and even dangerous. Several companies were working on a self-starter, and someone would have come up with one eventually, but the first effective one was the result of a tragic cranking accident.

Byron Carter, who had started an auto company called the Cartercar, was driving in 1910 when he saw a woman in a stalled Cadillac. Ever the gentleman, he stopped and cranked her car to restart it. The crank handle unexpectedly spun, as they often did, and hit Carter in the face. He later died of his injuries.

Carter was a good friend of Henry Leland, the founder of Cadillac, who was devastated by the news. He contacted Charles Kettering, an engineer at Delco, and demanded he find a solution. Prior to his automotive career, Kettering had worked at National Cash Register, where he had invented a small electric motor to take the place of hand-cranking a register to ring up a sale and open the till. He adapted the design for an ignition system, and the 1912 Cadillac was the first on the market able to start its own engine.

Price Stickers – Thanks to a senator

When it’s on the dealer’s lot, every new vehicle has to display a window sticker showing such information as its base price, engine and transmission, its options and their prices, warranty, and its destination charge, along with its rated fuel economy and vehicle information number (VIN). It’s popularly known as a Monroney sticker, and that’s thanks to a senator from Oklahoma, Almer Stillwell “Mike” Monroney.

For all that people may say about the “Fabulous Fifties”, it wasn’t really a great decade for consumers. Car dealers didn’t have to provide detailed pricing to customers, and it was common for them to pad the sticker on everything they could, right to the financing and freight charges. This gouging infuriated Monroney, and in 1958, he sponsored the Automobile Information Disclosure Act.

The bill passed, requiring manufacturers to deliver every vehicle with a sticker showing the manufacturer’s suggested retail cost of the vehicle and its options. The fuel economy ratings were added for model-year 1975, while graphs showing the vehicle’s efficiency and emissions ratings in comparison to the segment overall were added for 2013.

MacPherson Struts – Rear goes front

The spring-and-damper MacPherson strut, a common front-end component on cars today, actually started out in the rear – and in the 1940s. They’re named for Earle MacPherson, a GM engineer who designed them for the Cadet, a small car Chevrolet was developing. It would be rear-wheel drive, and MacPherson’s design would go on the rear suspension.

But the Cadet couldn’t come in under the anticipated small-car price that Chevrolet expected to stick on it. The company discontinued the program in 1947, and the Cadet never saw the light of day. That angered MacPherson, who cleaned out his desk and, of all things, moved to England to work for Ford. He also took his suspension plans with him, altering them just enough that it didn’t violate the original patent. The MacPherson strut made its debut on the front suspension of the 1951 Ford Consul.