Knowledge from road construction and maintanence engineers and contractors

Basic Components of Road Marking Macine

Pavement marking equipment comes in many shapes and sizes. All equipment manufacturers have their own configuration of basic components for a given application. A long-line paint truck manufactured by one company may look considerably different from the paint truck of a different manufacturer.

Although a specific machine is built to apply a specific type of material, all pavement marking equipment, except preformed tape applicators, will generally fall into one of the following categories: long-distance road marking machine and hand-push road marking machine.

Long-distance road marking machine, as the name implies, are designed to produce long distance pavement markings. They are self-propelled and are equipped to carry relatively larger quantities of road marking paint material. Most are set up with more than one applicator or spray gun. Hand-push road marking machines, which are much smaller than self-propelled road marking machine, are generally designed for operators to walk behind. They can only carry a limited quantity of paint material.

Long-distance road marking machines vary somewhat from the specific systems they incorporate based on the type of pavement marking material they are designed to apply (paint, epoxy, thermoplastic paint, etc.). However, the following components can be found on all Long-distance road marking machines:
1. Air compressor (airless applicators included)
2. Material holding tank (with mechanical agitators)
3. Reflective bead tank (pressurized)
4. Cleaning system (cannot be in-line system)
5. Material heating system (if necessary)
6. Material applicators (spray guns, etc.)
7 Reflective bead guns
8. Control system (spray gun control, skip timer, etc.)
9. Counter system (for measuring distance and/or paint material)
10. Guidance aid (some means for the operator to line up with the road or with existing markings)

Pre-stripe Inspection

The following is the recommended procedure for the engineer prior to beginning work on the project:

a. The engineer or designee will become familiar with the equipment by walking around it with the operator. They should discuss how the machine is set up and how it operates. During this discussion, the engineer or designee should be assured that everything is in working order. The preceding checklist may be used as a guide for this procedure.
b. The contractor shall apply a sample marking for inspection. While this is taking place, the engineer or designee will ensure that the contractor is taking quality control test samples for thickness and width of material, and reflective bead application rate(according to government agency specifications). The results of the quality control tests shall be reviewed and discussed with the contractor.
c. Before proceeding with the work, the engineer or designee will inspect the marking and test panels for quality, clean edges, even bead distribution, proper bead depth, required width, and general appearance.

If any problems or inconsistencies are discovered, do not proceed the maring work!

Quality Control

Clear communication and cooperation yields positive inspector/contractor interaction and helps ensure quality. This is essential regardless of the type of work. Discuss any problems with the contractor's certified quality control technician and stay informed of the adjustments the contractor makes to correct them. The following guidelines will ensure proper quality:

Once the work is in progress, the engineer and contractor's quality control technician shall periodically stop, get out of the truck, and inspect the line.
Continuous close attention to the appearance of the line is the best way to ensure quality work.
Generally, inspection of the actual marking is the best tool for determining equipment problems.
Proper width does not ensure even edges.
Proper material thickness does not ensure adhesion.
Proper bead application rate does not ensure either retention or proper embedment.
To ensure quality, the pavement markings must be inspected closely.

Typically, the contractor's certified quality control technician is required to make the quality control checks according to the government agency's specifications. The purpose behind any quality control plan is to ensure quality. Whenever there are any doubts about the quality of the work, they MUST be investigated.

Deficiencies may or may not be due to equipment problems. When everything is working properly, pavement markings can be compared to an orchestra; all the components must work together. Material properties, weather conditions and operator skill can all affect the quality of the final marking. Diagnosing the cause or combination of causes for a given problem can be very difficult. Engineers and inspectors who are knowledgeable about pavement marking equipment are better able to identify equipment problems.

As always, it is the responsibility of the contractor to solve the problem. However, this should never be misconstrued to lead the engineer away from helping to identify problems. In other words, although the engineer cannot tell the contractor how to fix a problem, knowledgeable engineers can and should be considered a valuable tool for the contractor, always keeping in mind that quality is the main goal.