There's more from the DOI:

"The Department is aware of comments and criticism about the need to repaint kerbs around the courses. Whilst it is the case that the Department is currently responsible for doing this work, it is carried out in accordance with a Schedule provided by the race organisers. This Schedule indicates the areas where edge lines and kerb painting assists competitors in safely negotiating the course. In the past kerbs have been painted in accordance with tradition rather than to address specific safety needs. In the interests of minimising risk, the locations of painted kerbs and road edge markings have been fully reviewed by the ACU and painting is now only carried out in the locations specifically identified in their schedule."

Nonsense! Painting of kerbs in accordance with tradition is a Northern Ireland art-form.

This is more about saving paint and saving face, although the finger is now pointing directly at the ACU.