Police Powers (Vehicle Interception) Act 2000

A police officer may, with an authority granted under section 6, establish a roadblock or use a vehicle immobilising device on a public street, a road-related area or other area if the police officer reasonably believes that – establishing the roadblock or using the vehicle immobilising device would significantly improve the prospects of apprehending or locating a person in or on any vehicle who the officer reasonably believes – has committed an offence punishable upon indictment; or is or may be endangering the property, life or safety of another person; or it is necessary to establish the roadblock or use the vehicle immobilising device for the protection of life or property; or an offence has been, is being or is likely to be committed and that, for the purposes of performing his or her functions under this or any other Act, it is necessary to detain a vehicle, a driver or a passenger in or on a vehicle.

A roadblock may consist of any appropriate form of barrier or obstruction preventing or limiting the passage of vehicles.