'Cǎi shāchē' literally means 'to step on the brakes' — combining 踩 (cǎi, 'to step on/tread'), 刹 (shā, 'to stop abruptly'), and 车 (chē, 'vehicle'). It’s a common, colloquial verb phrase used primarily for stopping motor vehicles like cars, motorcycles, or bicycles by pressing the brake pedal or lever. Unlike formal terms like '制动' (zhìdòng), this expression is vivid and action-oriented, reflecting physical movement and immediate response.

The phrase emphasizes urgency or intentionality — it's not just 'braking' in general, but actively applying brakes, often to avoid danger or slow down quickly. It appears frequently in driving instructions, traffic safety contexts, and everyday conversation about road situations. While originally tied to pedal-operated brakes, it’s now extended metaphorically (e.g., '踩刹车' for slowing down a project), though literal vehicle use remains dominant.