(a) A police officer may not direct any driver, owner, or passenger of a motor vehicle, other than a police vehicle, to participate in a roadblock.
(b) If any police officer of this State or any political subdivision of this State, while otherwise acting within the scope of his authority in enforcing any law, directs the driver, owner, or passenger of a motor vehicle other than a police vehicle to participate in a roadblock to assist him in enforcing that law or in apprehending any person suspected of violating or known to have violated that law, this State or the political subdivision, as the case may be, is liable for the damages or injuries proximately caused by participation in the roadblock.
(c) This State or a political subdivision of this State may use the defense of contributory negligence and assert the doctrine of last clear chance in an action brought or defense raised under subsection (b) of this section.