Another Dunedin motorist has captured footage of shocking driving on city's streets, this time featuring a flying bag of rubbish and a foul-mouthed tirade.

Dashcam footage from a following vehicle begins as the motorist pulls up behind a Toyota Corolla sedan, stopped in traffic in Crawford St near Briscoes, about 5.30pm on February 22.

When the sedan remains stationary, despite traffic moving forward, the filming driver honks their horn four times.

The sedan begins to move forward, before its front-seat passenger suddenly hurls a plastic bag full of rubbish out of the left-hand window, which hits a passing hatchback in the neighbouring lane.

Cans and plastic bottles litter the road as the filming car continues to follow the sedan.

A motorist flings a bag of rubbish from a car in Crawford St in this video image captured by another driver last month. Image: supplied

At the intersection of Crawford and Jervois Sts, both vehicles pull up at a red light.

The sedan shifts into the right-hand turning lane as the other driver pulls alongside and begins remonstrating with the litter-bug motorist.

The following driver is met with abuse, and an angry and vulgar reply.

"What? What the f...?! What's your problem?"

When the lights change, the sedan swerves in front of straight-ahead traffic, crosses two lanes and speeds off towards Police St.

The driver who captured the video reported the incident to police the same day using its Community Roadwatch form.

That driver supplied the video to the Otago Daily Times after another motorist was captured last week repeatedly crossing the centre line in Warrender St.

They asked to remain anonymous, citing concerns about the safety of their family members.

The offending driver did "not sound stable at all", the following driver said.

A police spokeswoman said that they were attempting to locate the offending driver.

Dunedin police (03) 471-4800, Crimestoppers 0800 555-111.

george.block@odt.co.nz