Police said the woman, who was travelling in a black Landcruiser, was intercepted at 11am.
The interception came less than an hour after she allegedly fired a shot from a silver gel-blaster into a white vehicle on the M1 at Stapylton.
“All three occupants of the vehicle – two men and one woman – were spoken to by police,” police said.
“The men were later released, and the woman is currently assisting police with investigations.”
A search of the Landcruiser allegedly located a silver gel-blaster in the centre console.
The second vehicle has not been located. Police said there’s no evidence to suggest anyone was injured.
A gel blaster is a life-like toy gun that’s designed to fire a gel pellet.
Anyone with information, or dashcam vision, is urged to come forward.