Road edges should be delineated with guideposts to assist drivers to safely negotiate the roads and position their vehicles correctly during night time driving. Guideposts are important for indicating the alignment of the road ahead, especially at horizontal and vertical curves.

The type of mining road delineation depends, amongst other factors, on the type of roads and vehicles as well as on the speed limit.

Delineators should be consistently installed as per the standard that applies on public roads – red delineators on the left and white delineators on the right side (in the Australian context). The reflectors should be made of highly reflective materials.

As a guide, on mining roads, guideposts should be placed at:

• 50 m intervals on straight sections and 30 m on curves and corners
• 1.5 to 2.0 m height
• 0.5 to 1.0 m from road verge.

On supporting roads (i.e. roads used by vehicles other than the mining haulage fleet), guideposts should be installed as per the guidance of the Australian Standard AS1742. A minimum of two pairs of guideposts should be visible at all times when travelling at the permitted speed. They should be installed approximately 1.0-1.5 m from trafficable lanes to reduce the accumulation of dirt.

Metal star pickets are sometimes used for mounting guide posts. However, it should be recognised that star pickets can become a hazard if struck by a vehicle and left behind on the edge of roads. Alternative installation methods, such as wooden pickets or driving posts into the ground are better. Guideposts are usually installed on windrows but they should not be installed too high as they will not reflect the vehicle lights appropriately.

Different types of guideposts are used on Australian mines. One of the common types are round poly pipes with red, white or red and white reflective tape markings. The problem with this installation is that they either do not provide clear indication of the side of the road where they are installed (in the case where both colours are installed on a single post) or can be turned around and display the wrong colour. Preference should be given to rectangular posts or regular highway style of guideposts as they cannot be turned around.

Mining road delineation should be visible in reduced visibility conditions. In order to ensure the effectiveness of installed guideposts, there should be a program of scheduled and as-required inspection and maintenance. Damaged, dirty or missing guideposts should be repaired, washed or replaced.