In vehicles with automatic transmissions, the parking brake was originally intended for emergency stopping (for instance, if the foot brake completely failed due to a loss of hydraulic pressure or other malfunction). As safety regulations became more stringent in the 1980s, and modern brake systems became more reliable (using dual-circuit hydraulics and low-brake-fluid sensors), the likelihood of brake failure reduced; in most cases this failure might be indicated through a brake warning light appearing on the dashboard. In the event of brake failure, the parking brake lever should be slowly engaged to prevent locking up the wheels and reduce speed.