There's no doubt that modern cars are safer than ever before. Advances in engineering and the addition of active safety features have made cars not just perform better in crash tests, but also help drivers avoid an accident in the first place. Hence we see terms such as 'five-star safety rating' or 'top safety pick'. But how do these ratings come about?

Crashing cars for science: Safety ratings explained

Vehicle safety organizations

Before we get to how the cars are rated, let's first take a brief look at the agencies who give out these scores in the first place.

There are five major crash test agencies that are commonly referred to when giving safety ratings. Some of these include the Euro New Car Assesment Program (Euro NCAP), Australasia New Car Assesment Program (ANCAP), Japan New Car Assesment Program (JNCAP), which all fall under the Global New Car Assesment Program. Over in the U.S, there's the National Highway Traffic Safety Administration (NHTSA) and Insurance Institute for Highway Safety (IIHS).

The various New Car Assesment programs, along with NHTSA, rate cars with a star grading system with no stars being the lowest and five being the highest. The IIHS meanwhile rates their cars from Poor, Marginal, Acceptable and Good.

Crashing cars for science: Safety ratings explained

Impact testing

The first half of the scores come from the initial crash testing. Normally, it comprises of a full-front, front-offset and side impact test. A full-front crash test sees a car crashing into a wall head on while an offset crash test sends the car into a barrier off-center (hence offset). The latter is more difficult to pass as the forces are only on one side of the car. Side impact tests may vary from one agency to another with some using a pole to crash into while others simulate another car slamming into the side of the vehicle.

Crashing cars for science: Safety ratings explained

How they're rated

From the ruins of the wreckage, the researches do an initial inspection. Did the roof buckle? Did the doors swing open in the impact? Did the pedals and the dashboard move back into the dummy? If so, then it's likely that the car's structure did not hold up. The researchers call it cabin intrusion which is a bad thing because if parts of the interior move closer to the dummy, there's more risk of hitting sharp edges.

Besides the initial inspection, the cars, along with the crash test dummies, are loaded with sensors to measure forces in order for researchers to quantify the results of the test. With data from the car and the dummies, researchers analyze the measurements taken from the sensors. The lower the forces, the less risk of injury and vice versa. Once the data is compiled, that is how the agencies rate how safe each car is, at least when it comes to occupant protection in a crash.

Crashing cars for science: Safety ratings explained

Of course, there is a simpler way of checking how the dummies fared during the test. All these agencies paint different parts of it in various colors, particularly in the face and leg area. That way, they see where the parts of the dummy hit the car's interior as the paint brushes off.

However, the story doesn't end there. In the past, these agencies rated soley on crash test performance but now, there are other factors they have considered too. These days, they also rate pedestrian safety, along with active safety systems such as stability control and automatic emergency braking. These are now factored in the overall safety rating of the car.

Accident avoidance

While a car can get full marks in crash protection, car safety agencies will only give top scores to cars equipped with driver aids and active safety systems. Features like stability control and traction control help boost a car's rating, and the addition of automatic emergency braking is a definite advantage. Some organizations will even go as far as knocking down points if the car isn't equipped with traction control.

Just because the cars have these driving aids, it doesn't mean that it will automatically be rated high. These devices are vigorously tested to see if the systems are, indeed, up to par. For stability control systems, these are tested by suddenly jerking the wheel and getting back on course. It simulates an emergency maneuver and if the car does the test successfully, then it's one step closer to becoming a highly-rated vehicle.

If a car is equipped with automatic emergency braking (AEB), they test it as well. For this test, they simulate a scenario wherein the car in fron suddenly stops or slows down. The procedure is done by running the car at both 50 and 60 km/h and it must slow down or stop right before it hits the soft dummy vehicle (which is pulled by a real car). If the system can react in time and avoid the hit, then it gets higher marks.

As if the previous test above wasn't tough enough, they also test AEBs for pedestrians. Dummies are employed yet again as it crosses in front of the car at varying rates of speed. If it's not hit, then a higher rating is given.

Crashing cars for science: Safety ratings explained

Overall safety in mind

Yes, the modern safety test is a lot tougher than it was a decade ago. Today, these safety organizations have overall safety in mind and you could say it's for the best. Not only do modern cars have to perform well in an event of a crash, they must be able to help avoid them from happening in the first place.

As these organizations publish their findings and ratings, they can also help consumers choose safer cars for their next purchase. With their initiatives, the drive for lesser deaths and injuries due to vehicular accidents is introducing new innovations and engineering solutions in the cars of today. As these agencies continue doing their testing, you can be assured that the car of the future will be safer than ever.

Of course, your safety starts with one simple step: Buckle up.