Why does the car roll when in neutral with the handbrake on?

[Myra]

If the handbrake is not fully engaged while the car is in neutral, the vehicle may roll on steep slopes. Here are the relevant details: Neutral: Neutral typically refers to the state where the gear lever of a motor vehicle is not engaged in any forward or reverse gear, completely separating the transmission from the drive wheels. In manual transmissions, neutral is the middle position, while in automatic transmissions, it is marked as "N". Handbrake: Handbrakes are divided into electronic handbrakes and mechanical handbrakes. The electronic handbrake has only one switch that controls the handbrake motor on the rear wheels, using the motor's rotational force to engage and release the handbrake without requiring manual effort. The electronic handbrake is simpler to use; it only determines whether to engage the handbrake but not the tightness. Once engaged, it provides maximum braking force.