When making a purchase decision, people may often buy a particular vehicle for the myriad safety ‘features’ that are available in that car. However, does the addition of extra airbags or more electronic alerts actually make your car safer? Let’s explore to find out more about passenger vehicle safety.
What is safety in an automobile?
Automotive safety begins at a more elemental level; rather than improvement through “more safety features”, it can instead be broadly classified into two parts, namely active safety and passive safety.
Active safety refers to all those safety maneuvers and mechanisms that are aimed at avoiding an accident in the first place. Passive safety, on the other hand, enlists the provisions built into the vehicle that come into action when an accident actually happens.
Thus, a safe car can be defined as one that behaves predictably and is reliable to drive, while also protecting the occupants in the case of an adverse event. The number of safety features can vary widely between cars, based on positioning in the market and price.
Active safety
Active safety consists of features that are aimed to make a vehicle predictable in its movements and driver-friendly so that mishaps can be avoided altogether. A good active safety system is developed at a more fundamental level.
1. Design
Design does not solely pertain to the shape and aesthetics that impart visual appeal, but also to various engineering considerations. Vehicular design has two distinct roles to play in both active and passive safety systems.
i. Chassis
In the past, cars were manufactured on a ‘body-on-frame’ platform, which offered great load-bearing capabilities, but did little in terms of drive stability and protection. The development of the modern monocoque chassis has resulted in far more stable and safer architecture.
ii. Center of gravity
A lower center of gravity results in a more stable ride, especially around corners and at high speeds, in comparison to a car with a higher center of gravity. The chances of a vehicle rolling over are significantly reduced by lowering the center of gravity. In high seating cars, provisions like anti-roll bars are put in the chassis to reduce chassis flex, which contributes to body roll.
iii. Wheelbase
A smaller wheelbase reduces the turning radius of the car (for reference, a small hatchback can turn much faster than a limousine). This, in turn, makes it easier to perform evasive maneuvers.
iv. Weight distribution
A heavy vehicle exerts more force on the ground, thus generating more friction. This results in a better grip and prevents the vehicle from losing traction. Apart from the total weight, weight distribution within the vehicle plays an important role in its handling.
The aforementioned parameters are not binding for vehicle design, as vehicles differ vastly in their shape, size, features and applications. Higher load-bearing vehicles might have a body-on-frame chassis and a higher center of gravity.
Similarly, luxury cars often have long wheelbases. While it is desirable to have a heavy vehicle to maintain traction, heavy vehicles can be difficult to maneuver and fuel-intensive to run. Thus, these parameters must be adjusted to achieve a trade-off of optimal safety and practicality of application.
