Automobile safety: A never-ending full-scale marathon

A popular car brand and a traffic accident have refocused the attention of all sectors of society on car safety.

On October 13th, a collision accident occurred in Chengdu. After a Xiaomi SU7 Ultra collided while in motion, it caught fire and burned, and the driver died. According to the notification from the Chengdu Public Security Bureau, the driver of the accident vehicle was suspected of drunk driving.

Some netizens posted on - site videos. After the accident, many enthusiastic citizens tried to rescue the driver. They repeatedly tried to pull the door handle but couldn't open the door from the outside. Finally, the rescue team opened the door with professional demolition tools.

This scene has once again made the door lock system and door handle design of new - energy vehicles the focus of public discussion.

In 2014, Tesla launched the mass - produced Model S. This groundbreaking new - energy vehicle adopted a non - mechanical door handle design. As Tesla gained wide recognition in the high - end market, many domestic new - energy vehicle brands began to imitate this design and successively launched new cars with non - mechanical door handles.

Initially, public discussions about the "new - style" door handle design of new - energy vehicles focused on experience and convenience: fully hidden door handles may freeze in winter and become unusable; various electronic door handles may confuse first - time users.

Later, after multiple tragic accidents in which the doors couldn't be opened in new - energy vehicle brands, people's doubts about vehicle safety were magnified, pushing the design of car door locks and handles into the spotlight of public opinion.

A car is a product highly related to life safety. If it can be put on the shelf for consumers to choose, it means that the product has passed the necessary safety tests.

The industry should neither ignore the safety issues of door locks and handles exposed in specific accidents nor overcorrect and hinder the technological progress of the industry. Car safety is a huge and complex project. Only by viewing problems rationally and objectively can we promote the common development of the entire industry in terms of experience and safety.

The safety logic of door locks: redundancy can only reduce the probability

The most fundamental mission of a car door lock is to ensure that the door can be reliably locked during driving, guarantee the safety of passengers and property inside the car, and prevent the door from accidentally opening due to vehicle bumps or misoperations during driving, which could throw the occupants out of the car.

With the development of technology, to prevent accidents caused by negligence, modern cars generally introduce automatic locking and unlocking procedures. For example, when the vehicle starts moving and the speed reaches 10 - 20 kilometers per hour, the vehicle automatically locks; in the event of a collision, the vehicle should actively unlock to facilitate rescue.

However, collision accidents are extremely complex.

A basic principle of car safety is to fix the position of the occupants during a collision, reduce displacement, and thus reduce injuries. The designs of seat belts and airbags are all based on this concept.

Therefore, at the moment of a car collision, the door lock usually locks immediately to prevent the occupants from being thrown out of the car during high - speed impact. Only after the vehicle stops moving will the unlocking command be executed to facilitate subsequent rescue.

This is a complex emergency procedure that requires precise release of functions at the right time. Its triggering logic is not simply a matter of judging "collided" or "not collided".

In response, the industry already has a mature and stable solution, which is to bind the decision - making signal to whether the airbag is deployed.

The airbag system is the highest - priority safety system in the whole vehicle. It has high - precision collision sensors, signal transmission wiring harnesses, and one - time ignition controllers. It is a high - cost and rigorously - programmed protection system.

After being bound to it, the emergency working logic of the car door lock is as follows: if the collision intensity does not reach the threshold for deploying the airbag, it usually means that the relative collision speed is low, and the occupants in the car are more likely to be conscious, so the system does not need to start the emergency unlocking.

Conversely, when the airbag is deployed, it indicates a severe collision, and the occupants may lose consciousness. In this case, the vehicle needs to execute the unlocking command to create conditions for rescue.

However, no car company can guarantee the absolute and unconditional effective operation of the car door lock emergency procedure. The entire industry is continuously working on solving the power supply problem of key systems after a collision.

A common practice is to design dual - power redundancy to ensure that the backup link can still be used after the main link fails. But the pursuit of safety is endless.

Currently, some brands have even arranged a third - level redundancy for door locks and handles, setting up an independent power supply and placing it under the second - row seats where the collision risk is relatively low. This increases the probability of maintaining the integrity of the independent power supply in a collision accident.

However, it must be admitted that no matter how many levels of redundancy there are, the basis of a car door lock is still the cycle of "power supply - wiring harness - controller".

Collision accidents are unpredictable. The speed, collision object, and scene of each accident have infinite combinations. This means that no system can guarantee effectiveness in 100% of scenarios.

The core value of safety redundancy lies in probability management. It cannot eliminate risks but can only try its best to reduce them.

Non - mechanical door handles: technology and regulations are in a period of co - existence and adaptation

Another focus of current public controversy is the "non - mechanical door handle".

In the era of traditional fuel - powered cars, door handles were usually mechanical mechanisms that were "what you see is what you get". Through ropes or levers, the door - opening action was direct and relied on the physical structure. This type of door handle is very commonly used in the automotive industry, from economy cars worth tens of thousands of yuan to luxury super - cars worth millions of yuan.

The meaning of "non - mechanical door handle" is that the process of opening the door must go through an electronic system. There are mainly two forms:

One is the electronic handle, usually fully hidden, which needs to be electrically ejected before it can be operated; the other is the electronic operation end, such as the common button - type door opening inside the car. In this case, the button triggers a micro - motor instead of a physical cable.

In 2014, Tesla began to use this design in models such as the Model S and Model X. After 2019, the Model Y and Model 3 were continuously popular. The "non - mechanical" door handle began to be well - known to consumers and imitated by other brands in the market. In addition, dozens of models from multiple brands are using a similar "non - mechanical" door handle design.

Based on comprehensive data from all parties, nearly one million such new cars entered the market in 2024 alone. From the perspective of the entire market, there are currently more than two million users using "non - mechanical" door handles. It is no exaggeration to say that the "non - mechanical" door handle has almost become a mature technology and configuration.

However, consumers' concerns are understandable.

Because the premise for realizing all electronic functions is a stable power supply. A collision may damage the power supply or wiring harness, posing a potential risk that the door cannot be opened.

From a technical principle perspective, this risk does exist.

However, market demand is driving the popularization of "non - mechanical door handles". Nowadays, from cars worth as little as 30,000 yuan to those worth millions of yuan, nearly one million cars sold in the automotive market each year adopt non - mechanical door handle designs.

In fact, the current national standards have clear requirements for the opening of car doors after a collision.

In the current national standards for vehicle access, there are three requirements related to car doors in collisions, namely GB11551 - 2014, GB20071 - 2006, and GB2072 - 2024. These three standards require that "after the test, at least one door should be able to be opened" for frontal, side, and rear - end collisions.

This means that vehicles on the market for sale meet the corresponding access specifications. However, access specifications are not static, and car door handles are also undergoing safety upgrades.

In September 2025, the Ministry of Industry and Information Technology released a draft for soliciting opinions on the mandatory national standard "Safety Technical Requirements for Car Door Handles". The core of this standard is to clearly require that both the interior and exterior door handles of cars must be equipped with a mechanical release function, aiming to reduce the risk that the electronic door handle fails and hinders rescue or escape in emergencies such as collisions and power outages.

This is the world's first national - level technical standard for "non - mechanical" door handles. Before this, regulatory requirements for car door handles mainly focused on physical durability.

We have to admit that technological development often explores first, and the establishment of regulations is a necessary step that follows in the process of technology gradually maturing and popularizing to ensure safety and guide orderly development.

The emergence of regulations is not to restrict innovation but to define the safety boundaries for technological applications, prevent potential risks, and thus promote its development in a more reliable and responsible direction. There is always a period of co - existence and adaptation between technological development and the establishment of regulations, which is an inevitable stage for the industry to mature.

6.89 times the national standard energy, vehicles also have physical limits

The meaning of access regulations is that within the speed required by the standard, the vehicle must meet the condition that the door can be opened before the new car can be put on the market.

The speed requirements of national standards and mainstream collision tests are usually around 50 to 64 km/h. However, in several recent serious accidents that have attracted public attention, the collision speeds have far exceeded this threshold.

For example, in the Chengdu accident of the Xiaomi SU7 Ultra, several car owners around the accident vehicle posted video clips from their dash - cams. Based on the time and road distance, it was estimated that the speed of the accident vehicle at the moment of collision exceeded 160 km/h. The collision energy was 6.89 times that of the current national standard.

The Beijing Public Security Traffic Management Bureau once released a safety knowledge: if a car traveling at a speed of more than 160 kilometers per hour has a tire - burst accident, regardless of whether the occupants are wearing seat belts, the mortality rate is 100%.

The core idea of car safety design is to absorb collision energy through the deformation of the crumple zones at the front and rear of the car and ensure the firmness and integrity of the "survival space" of the passenger compartment. Finally, the remaining energy is borne by restraint systems such as seat belts and airbags to protect the occupants.

However, this system has a clear load - bearing limit.

A collision at 160 km/h is as severe as falling from a height of more than ten floors. At this time, the design of the crumple zones of the vehicle is difficult to effectively absorb all the energy. The passenger compartment may be severely deformed, and the occupants face multiple risks including but not limited to fatal internal injuries, head injuries, and multiple fractures.

Returning to the topic that the public is concerned about, why can't the door be opened in a high - speed collision?

The car door is a complex and precise structure. For the door to open and close freely, the door lock, hinge, and handle need to cooperate precisely. Failure of any link may lead to structural failure.

In an extremely high - speed collision, the first part of the door structure to be damaged is the door frame structure. At this time, what hinders the rescue from opening the door is no longer the door lock program but the severe deformation of the vehicle body structure.

Although there are occasional reports of occupants surviving in high - speed accidents, these are usually rare cases due to a combination of multiple factors, including the collision angle, the perfect function of seat belts and airbags, the buffering properties of the collision object, and a great deal of luck. They should not be interpreted as any model being able to absolutely "withstand" such high - speed collisions.

Of course, safety is not a static proposition.

Just as the initial reason for the emergence of car doors was to prevent passengers from being thrown out, car safety will continue to develop with technology and the times. The speed requirements for national - standard collision tests are also gradually increasing. For example, the speed requirement for the 40% frontal offset collision has been increased from 56 km/h to 64 km/h.

However, the essence of safety redundancy is only to reduce risks and increase the probability of rescue. It cannot prevent accidents from happening.

The steering wheel, accelerator, and brake are still in the hands of the driver. All discussions about car safety will ultimately return to one origin: safe driving.