Police said the Calwell man, Bradley Robert Stevenson, deliberately crashed his car into two other vehicles when they stopped at traffic lights, heavily damaging and immobilising all three and damaging a fourth.

Mr Stevenson had earlier allegedly approached the woman, his former colleague, at an Isabella Plains workplace in possession of a large knife.

Police said when the woman and another colleague left in separate cars, the 26-year-old followed them and intentionally caused the collision.

Police attended the scene and allegedly seized two large knives from Mr Stevenson's vehicle, and arrested him.

Mr Stevenson fronted the ACT Magistrates Court on Thursday charged with stalking, possessing an offensive weapon and using an offensive weapon dangerous to a person.

Special Magistrate Margaret Hunter ordered that Mr Stevenson be taken to hospital for a mental health assessment.

Police said they anticipated laying further charges regarding the collision once their investigations had concluded.

Anyone who witnessed, or who may have dash-cam footage of the collision is urged to contact Crime Stoppers on 1800 333 000, or via the Crime Stoppers ACT website and quote reference 6616812. Information can be provided anonymously.