https://www.canlii.org/en/on/onca/doc/1952/1952canlii60/1952canlii60.html said:
The use of the term "due care", which means the care owing in the circumstances, makes it clear that, while the legal standard of care remains the same in the sense that it is always what the ordinary prudent men would do in the circumstances, the factual standard is constantly shifting, depending on road, visibility, weather conditions, traffic conditions that exist or may reasonably be expected, and any other conditions that an ordinary prudent driver would take into consideration.