"About four cop cars parked horizontally across the road, blocking all traffic to the motorway.
"The cops immediately got out of their cars and starting yelling on loud hailers and there was a lot of yelling back.
"This went on for some time. We didn't know what was going on, but we were all trapped in the middle of it in our cars."
Hawkesby said queuing motorists eventually got out of their cars to ask Police what was going on.
"They said they were making some arrests but you need to get back in your cars."
Police said they located a person - but no firearm was found and "no issues".
A short time later the road was opened to one lane of traffic. The road has now fully reopened.