Spike barriers, also known as tyre killers or spike strips, are designed to stop vehicles by puncturing their tires. They are typically used at security checkpoints or restricted areas to prevent unauthorized vehicle access. When a vehicle attempts to pass over the barrier, the spikes embedded in the road surface penetrate the tires, causing them to deflate and eventually stop the vehicle. Some spike barriers are manually activated, while others are automated and can be controlled remotely or through access control systems. Some systems also include the ability to lower the spikes in case of emergencies, such as fire or threats.