How many cats eyes are typically found on centre lines?

The correct answer indicates that cats' eyes, also known as reflective road studs, are typically installed at regular intervals along road centre lines, specifically in every other gap. This spacing is designed to enhance visibility for drivers, especially during nighttime or inclement weather conditions. By placing the reflective studs in every other gap, it provides a balance between visibility and cost-effectiveness, as well as preventing visual clutter that could distract drivers.

This practice follows common traffic management principles, where the goal is to enhance road safety without overwhelming visual signals. This spacing ensures that drivers can easily discern the lane markings and stay centered in their lanes. The other options do not reflect standard practices, as spacing every gap would lead to an excess of reflective markers, while one in every three gaps would not provide sufficient guidance. Similarly, linking the number of cats' eyes to hazard lines is not a standard measurement used in road markings.