Roll bars installed in vehicles are safety structures designed to protect occupants in the event of a rollover. They are typically made of steel and installed in the vehicle's passenger compartment, reinforcing its structure and providing additional safety protection in hazardous situations.

As an additional safety feature, the primary function of roll bars is to prevent the vehicle's roof from deforming in the event of a rollover. By providing a rigid and strong structure, roll bars help distribute the force of impact and minimize passenger compartment crushing.

However, roll bars are not installed in all cars. They are especially important in sports models, SUVs, and other vehicles that are prone to rollover due to their design or driving characteristics.

In addition to rollover protection, roll bars have other benefits. In some cases, they are used to improve chassis rigidity and vehicle stability, which can result in improved ride and handling. They are also commonly used in racing vehicles, where they are mandatory in many categories to ensure driver safety in extreme racing situations.

A vehicle rollover system also improves chassis rigidity, which translates into improved stability and vehicle response. It also provides greater structural strength, as it absorbs impact energy in the event of a collision. Due to their increased impact resistance, protection, and greater cornering precision, rollover bars offer improved performance to competitors.