620.11 MoDOT Pavement Marking Materials
| Divided Highways | Undivided Highways | Intersection Markings | ||
|---|---|---|---|---|
| Contractor Installations | Major Roads | High Build Paint with Type L Beads | High Build Paint with Type L Beads | Durable Intersection Marking Material |
| Minor Roads | Not applicable | Waterborne Paint with Type P Beads | ||
| MoDOT Installations | Major Roads – shall be striped annually unless retroreflectivity exceeds requirements for new pavement markings1 | Waterborne Paint with Type L beads (60° F and rising) | Waterborne Paint with Type PM beads (60° F and rising) | Durable
Intersection Marking Material, preformed thermoplastic or waterborne paint with Type PM beads |
| Regionally Significant Roads – shall be striped annually unless retroreflectivity exceeds requirements for new pavement markings1 | Not applicable | Waterborne Paint with Type PM beads (50° F and rising) or Cold weather paint with Type PM beads (35° F to 50° F) | ||
| Minor Roads≥400 AADT – maximum of 50% striped annually | ||||
| Minor Roads<400 AADT – maximum of 33.3% striped annually | ||||
| Surface Treatments | ||||
| 1 See Pavement Marking Acceptance Table | ||||
620.11.1 Permanent Pavement Markings
The selection of permanent pavement markings shall be based on the Pavement Marking Guidelines table.
Support. Contract work consists of furnishing and installing durable intersection markings, cold weather paint, high build waterborne paint, waterborne pavement marking, or epoxy.
Standard. On the final lift of resurfacing projects and on all new pavements, all pavement marking will be provided by contract. On surface treatment projects, all pavement marking will be provided by MoDOT.
Standard. All permanent marking materials shall be installed in accordance with the manufacturer's recommendations. Durable pavement markings, such as epoxy, used for lane lines shall be installed in a groove.
Guidance. For road segments with different pavement types less than 1,000 ft. long, such as a concrete bridge deck surrounded by asphalt, the pavement marking type for the surrounding pavement should be continued through the segment and contrast marking would not be required on the bridge deck.
Support. The materials that MoDOT uses for pavement marking are:
- A. Waterborne Paint. This material is the standard paint used by contractors and MoDOT forces. MoDOT forces use waterborne for all long line applications, while contracts should specify it on minor routes. Waterborne paint may be applied at a wet thickness of 15 mils to 24 mils. It may also be used for intersection markings when the life of the pavement is not expected to outlast a more durable product (see Preformed Pavement Marking Tape). See EPG 620.11 Guidelines for Using Water-Borne Traffic Paint.
- B. High Build Waterborne Paint. High Build paint can be applied in a thicker layer than normal waterborne paint and it is used by contractors when specified. High build paint may be applied at a wet thickness of up to 35 mils. High Build is one of two options for material to be used in contractor installations on divided highways. See EPG 620.11 Guidelines for Using Water-Borne Traffic Paint.
- C. Cold weather paint. This material is used in special situations when specified. Cold weather paint is a water-based material that can be used at lower temperatures. Cold weather paint is normally applied at a wet thickness of 15 mils. See EPG 620.11 Guidelines for Using Water-Borne Traffic Paint.
- D. Durable Intersection Marking Materials. Due to the excessive wear experienced in and around intersections, durable marking materials (preformed thermoplastic, cold applied tapes, extruded / sprayed thermoplastic or plural component liquid) should be used to mark intersection markings (stop bars, yield bars, arrows, words, symbols, hash bars, shields, etc.) . These materials will remain in place longer and reduce maintenance requirements.
- E. Temporary Removable Pavement Marking Tape. Temporary removable tape is used to delineate traffic lanes during construction. Preformed removable tape does not require special equipment to install or remove, however material costs are high, so it may only be cost effective in small quantities. The primary advantage is that the removal of this tape is inexpensive and will not scar the pavement. The primary disadvantages of tape are the higher material cost and weather constraints for installation. When establishing contract times and milestones, the potential timing of paving activities and weather constraints should be considered when selecting temporary pavement marking. A pay item for removal of the marking tape will be included if removal is required. Marking tape shall be applied as per manufacturer’s recommendation.
- F. Temporary Pavement Marking Tape. Temporary pavement marking tape is used in locations where the marking will be in place no more than two weeks. It is cost effective only in small quantities. Short-term pavement marking is not normally removed. If removal is required, removable tape is the preferred material. Short term marking should not be used for temporary lane transitions or bypasses. Marking tape shall be applied as per manufacturer’s recommendation.
- G. Temporary Raised Pavement Markers. Temporary raised pavement markers are used on contract leveling course and resurfacing projects on two or three lane roadways with no passing zone center striping to provide a temporary centerline until permanent marking is replaced. Temporary raised pavement markers are used in combination with the NO CENTER LINE sign. Temporary markers should also be used to provide a temporary lane line on 2-lane roadways with climbing lanes. Temporary markers may also be used to supplement other pavement marking in areas where emphasis is needed, such as on bypasses and lane transitions.
Markers dividing two lanes of traffic in the same direction have one reflective face that is white in color. The edgeline markers with two lanes of traffic in the same direction are yellow for the left edgeline and white for the right edgeline. Markers dividing two lanes of traffic in opposite directions have two opposing reflective faces that are yellow in color. The edge line markers with two lanes in opposite directions are white.
See Standard Plan 620.10 for details on using temporary raised pavement markers.
Temporary raised pavement markers are used primarily on pavement surface treatment projects. Surface treatment is defined as any pavement surfacing as defined in Sec 413 of the Standard Specifications. Type 1 markers are used for temporary edgeline marking and as part of the "cluster" marking of temporary lane lines.
Temporary raised pavement markers do require removal after the permanent marking is in place. They do not require a pay item for removal.
Standard. Snow plowable raised pavement markers (SRPMs) are neither being installed new nor reinstalled on any more projects. If the district chooses to leave the SRPM’s in place, both the reflectors and the shoes shall be maintained. The districts must assure SRPMs that remain in the pavement are regularly inspected. Where cold milling is being done, the removal of the SRPMs is included in the cost of cold milling. On surface treatment and resurfacing projects SRPMs shall be removed before application of the surface treatment or resurfacing. SRPMs shall not be left in place and covered by surface treatment or resurfacing.
Support. The night visibility of pavement markings is a direct result of the presence and quantity of the spherical glass or ceramic "beads" that are embedded in the pavement marking material. There are several types of beads used by MoDOT.
- A. Type P Beads. These are an intermediate blend of glass bead used by MoDOT forces and contractors when marking minor roadways. The "P" stands for performance.
- B. Type L Beads. These are a “large” glass bead. These beads are used by MoDOT striping forces and contractors on major routes to provide a level of wet night time performance.
Support. See Standard Specifications for Highway Construction, Section 1048, for material specifications of pavement markings.
Guidance. MoDOT forces typically apply beads to the wet paint at the rate shown in EPG 620.1.11 Traffic Marking Paint Application Rates. On contractor applied pavement markings, the glass beads are applied at a rate determined by the contractor to meet the minimum retroreflectivity requirements of the contract.
The bead guns on the stripers should be calibrated frequently to assure the proper application rate of beads is being applied to the painted line. The frequency of these calibrations is dependent on the bead guns and their ability to maintain a constant flow of beads. The calibration should be accomplished using an appropriate bead calibration kit. These kits contain a table to calculate the appropriate flow of beads for a given speed of the striper. This calibration should be performed a minimum of once every week of operation.
Spot checks should be performed using two methods. The first method is accomplished with the aid of an aluminum sign panel placed ahead of the striper on which the paint, without beads, is to be applied and a mil thickness gauge used to read the wet paint mil thickness. The bead application rate should also be checked at this time by measuring the volume of beads being dispensed over a given time period. These methods should be used to calibrate the striper at the beginning of each day.
The second method involves checking the amount of material used, both paint and beads, versus the miles marked. This method should be used throughout the remainder of the day to verify the proper material application rates are being maintained.
620.11.1.1 Wet Reflective Marking
Wet reflective markings are no longer used by MoDOT.
620.11.1.2 Contrast Marking
Guidance. Contrast marking should be used to enhance the visibility of white markings on concrete pavements. On either new concrete surfaces or diamond grinding projects, lane lines should include contrast markings. Contrast markings consist of standard white markings with an additional width of black marking on each side. Contrast markings should be maintained until the pavement ages or greys so that normal markings are adequate.
620.11.2 Traffic Marking Paint Application Rates
Standard. Typical application rates are:
| Material | Application Rate |
|---|---|
| Cold Weather Paint | 15 mils min. |
| High Build Waterborne Paint | Up to 18 mils (Minor Roads) |
| High Build Waterborne Paint | 22 mils min. (Major Roads) |
| Epoxy | 25 mils |
| Type PM Beads | 10 lbs/100 sq. ft. |
| Type L Beads | 15 lbs/100 sq. ft. |
| Applied wet mil thickness | Gallons used per mile of 4 in. line | Gallons used per mile of 6 in. line |
|---|---|---|
| 15 | 16.5 | 24.8 |
| 18 | 19.7 | 29.6 |
| 20 | 21.9 | 32.9 |
| 22 | 24.2 | 36.3 |
| 25 | 27.4 | 41.1 |
| 30 | 32.9 | 49.4 |
Guidance. Water borne paint should not be heated above 100 degrees Fahrenheit (refer to Guidelines for Using Waterborne Traffic Paint for the application of water borne paint).
During marginal weather conditions at the end of the striping season, in November and December, cold weather paint should be used.