INSPECTION & ACCEPTANCE
REFLECTIVE SHEETING
Reflective sheeting for signs, barricades, reboundable drums and other traffic control devices shall meet the requirements of Section 4186.03. Reflective sheeting is classified according to the performance characteristics given in ASTM D-4956 and this IM. The following is a guide for identifying the various types of sheeting. Actual classification is based on performance characteristics and not on sheeting construction. See Specifications for specific types required for various applications.
Approved Products are listed in the Materials Approved Products Listing Enterprise (MAPLE).
ASTM Type I - A medium intensity retroreflective sheeting referred to as "engineering grade" and typically enclosed lens glass bead sheeting.
ASTM Type II - A medium high intensity retroreflective sheeting sometimes referred to as "super engineering grade" and typically enclosed lens glass bead sheeting.
ASTM Type III - A high intensity retroreflective sheeting, that is typically encapsulated glass bead retroreflective material.
ASTM Type IV - A high intensity retroreflective sheeting. This sheeting is typically an unmetalized microprismatic retroreflective element material.
ASTM Type V - A super high intensity retroreflective sheeting. This sheeting is typically a metalized microprismatic retroreflective element material. Typically used for Delineator applications.
ASTM Type VI - An elastomeric high intensity retroreflective sheeting without adhesive. This sheeting is typically a vinyl microprismatic retroreflective material. Typically used on temporary roll up signs, channelizers, Drums, post bands, traffic cone collars & some warning signs.
ASTM Type VII – Discontinued designation. Replaced with Type VIII.
ASTM Type VIII - A prismatic very high intensity retroreflective sheeting. The sheeting is typically a unmetallized cube corner microprismatic retroreflective element material.
ASTM Type IX – Unmetalized cube corner microprismatic retroreflective element material.
ASTM Type X – Discontinued Designation. Replaced with Type VIII.
ASTM Type XI – A microprismatic, high intensity retroreflective sheeting. This sheeting is typically an unmetallized cube corner microprismatic retroreflective element material. Typically used on permanent signs, rigid work zone signs and delineators.
Type XI shall meet the initial material requirements as found in ASTM D4956.
Daytime Luminance Factor (Y%) for all sheeting Types shall meet ASTM D4956 Table 2 requirements. The following initial material requirements will apply for Orange and White:
Orange: Fluorescent orange sheeting shall have a minimum total luminance factor (Y) of 20% and non-fluorescent orange sheeting shall have a minimum (Y) of 10%. The sheeting shall meet the chromaticity color coordinates shown in the following Table.
White: White sheeting shall have a minimum total luminance factor (Y) of 27%. The sheeting shall meet the chromaticity color coordinates shown in the following Table.
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Color Specification Limits (Daytime) |
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Color Point |
Fluorescent Orange |
White |
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X |
Y |
X |
Y |
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1 |
0.583 |
0.416 |
0.303 |
0.300 |
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2 |
0.535 |
0.400 |
0.368 |
0.366 |
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3 |
0.595 |
0.351 |
0.340 |
0.393 |
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4 |
0.645 |
0.355 |
0.274 |
0.329 |
Daytime color specification limits shall meet ASTM D4956 Table 11 requirements.
Nighttime color specification limits shall meet ASTM D4956 Table 13 requirements.
All Reflective sheeting Types shall have an initial Coefficient of Retroreflection according to ASTM D 4956 for their respective Type designation.
Type XI sheeting shall have an initial Coefficient of retroreflection according to ASTM D 4956 and the following Table:
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Coefficient of Retroreflection |
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Observation Angle (Degree) |
Entrance Angle (Degree) |
Fluorescent Orange (Candela/lux/m2) |
White (Candela/lux/m2) |
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0.2 |
-4.0 |
175 |
580 |
|
0.2 |
+30.0 |
66 |
220 |
|
0.5 |
-4.0 |
125 |
420 |
|
0.5 |
+30.0 |
45 |
150 |
Acceptance of reflective sheeting for use on Department of Transportation projects or for contract purchases will be on the basis of manufacturer and brand name approval and the results of tests on monitor samples.
Approved manufacturers and brand names are listed in Appendix A.
Manufacturer and brand name approval will be based on test results from AASHTO Product Evaluation & Audit Solutions.
The weathered sheeting shall meet the requirements Iowa’s Standard Specification Article 4186.03 and Table 12 of ASTM D 4956.
Samples shall be submitted to the AASHTO Product Evaluation & Audit Solutions test deck in Minnesota. In the event the Minnesota deck is discontinued, the samples shall be submitted to the AASHTO Product Evaluation & Audit Solutions deck, which has weather conditions most similar to Iowa’s. Sheeting materials for use on rigid construction work zone signs shall be weathered for one year and roll up signs for six months. Sheeting materials for permanent signs shall be weathered for three years. The sheeting shall be evaluated with the manufacturer’s recommended ink, overlay films, and (if necessary) clear coat. AASHTO Product Evaluation & Audit Solutions Initial and one year data shall be supplied for construction work zone signs and other construction zone devices that utilize work zone sheeting for review. AASHTO Product Evaluation & Audit Solutions one, two and three year data shall be supplied for permanent signs for review.
In the event that a manufacturer alters a material that is either approved or in the approval process, and the same product designation is maintained, the manufacturer shall notify the Manufactured Materials Engineer for the Iowa DOT. A determination will be made on a case-by-case basis to continue with the approval or approval process. Substantial changes will require the sheeting to start a new approval process.
An approval will remain in effect unless withdrawn because of deficient test results on monitor samples.
Monitor samples will be secured at the discretion of the department according to IM 486.