The Iowa DOT is adopting 6-inch wide lines as the standard for interstates and primary highways, aligning with the national movement. This wider marking enhances safety, improving visibility and reducing run-off-the-road crashes. It also facilitates detection by vehicle automation and lane-assist systems, preparing for future technology.
Next Steps
We have been testing 6-inch wide lines on various projects and have received positive feedback. Within the next few years, we will begin installing 6-inch lines on all construction projects and existing lines will be repainted at 6 inches. To prepare for this change, specifications, standards, tabulations, and software packages are being updated to make 6-inch lines the default.
The 4-inch wide line styles will not be removed. We recognize that the 4-inch wide lines still have a use and we will continue to install and refresh pavement markings at 4 inches until funding is established for the transition. These changes do not alter design or construction workflows; they establish the groundwork to ensure our documentation is ready for a future switch to 6-inch lines.
When Changes Go Into Effect
Please see the information and links below for changes that will go into effect with projects let in April 2024 and after.
Specification Changes
The specification changes have been approved so that 6-inch width is the method of measurement (2527.04 B). This change will be posted online before April 2024.
Standards
Tabulations
The Tab program has been updated to include these changes. Login to the Project Design Tabulations Application
Pavement Marking Changes Flyer
New Bid Item Code
| New Item Code | Old Item Code | Item Description | Units | NEW EST. UNIT PRICE |
|---|---|---|---|---|
| 2527-9263209 | 2527-9263109 | PAINTED PAVEMENT MARKING, WATERBORNE OR SOLVENT-BASED | STA | $57.00 |
| 2527-9263212 | 2527-9263112 | PAINTED PAVEMENT MARKINGS, HIGH-BUILD WATERBORNE | STA | $93.00 |
| 2527-9263216 | 2527-9263116 | PAINTED PAVEMENT MARKING, MULTI-COMPONENT LIQUID | STA | $165.00 |
| 2527-9263217 | 2527-9263117 | PAINTED PAVEMENT MARKINGS, DURABLE | STA | $219.00 |
| 2527-9263218 | 2527-9263118 | PAINTED PAVEMENT MARKINGS | STA | IRREGULAR |
| 2527-9263222 | 2527-9263122 | PERMANENT TAPE MARKINGS, REGULAR MARKING TAPE | STA | NOT USED |
| 2527-9263224 | 2527-9263124 | PERMANENT TAPE MARKINGS, PREFORMED POLYMER MARKING MATERIAL | STA | NOT USED |
| 2527-9263225 | 2527-9263125 | PERMANENT TAPE MARKINGS, PREFORMED THERMOPLASTIC MARKING MATERIAL | STA | $693.00 |
| 2527-9263226 | 2527-9263126 | PERMANENT TAPE MARKINGS, PROFILED PAVEMENT MARKING TAPE | STA | NOT USED |
| 2527-9263228 | 2527-9263128 | PERMANENT TAPE MARKINGS, INTERSECTION MARKING TAPE | STA | $787.50 |
| 2527-9263231 | 2527-9263131 | WET RETROREFLECTIVE REMOVABLE TAPE MARKINGS | STA | $286.50 |
| 2527-9263181 | 2527-9263180 | PAVEMENT MARKINGS REMOVED | STA | $79.50 |
| 2527-9263233 | 2527-9263600 | REMOVABLE, NONREFLECTIVE, PREFORMED TAPE | STA | $697.50 |
| 2527-9270112 | 2527-9270111 | GROOVES CUT FOR PAVEMENT MARKINGS | STA | $88.50 |
New Paint Factors
| Line Type | Factor | Discription | Line Type | Factor | Discription | Line Type | Factor | Description |
|---|---|---|---|---|---|---|---|---|
| BCY4 | 0.17 | 4" Broken Centerline | DLW4 | 0.22 | 4" Dotted Line | RLY4 | 0.67 | 4" Ramp Edge Line |
| BCY6 | 0.25 | 6" Broken Centerline | DLW6 | 0.33 | 6" Dotted Line | RLY6 | 1.00 | 6" Ramp Edge Line |
| BLC6 | 0.50 | 6" Black/White dash | DLY4 | 0.22 | 4" Dotted Line | SLW2 | 4.00 | Stop Line |
| BLW4 | 0.17 | 4" Broken Lane Line | DLY6 | 0.33 | 6" Dotted Line | SLW4 | 0.67 | 4" Solid Lane Line |
| BLW6 | 0.25 | 4" Broken Lane Line | ELW4 | 0.67 | 4" Edge Line | SLW6 | 1.00 | 6" Solid Lane Line |
| CBW6 | 10.00 | Crosswalk Bar | ELW6 | 1.00 | 6" Edge Line | SPW4 | 2.16 | 4" Sloped Curb |
| CHW10 | 1.67 | 10" Channelizing Line | ELY4 | 0.67 | 4" Edge Line | SPW6 | 2.28 | 6" Sloped Curb |
| CHW8 | 1.33 | 8" Channelizing Line | ELY6 | 1.00 | 6" Edge Line | SPY4 | 2.16 | 4" Sloped Curb |
| CHY10 | 1.67 | 10" Channelizing Line | LDW10 | 0.42 | 10" Lane Drop Line | SPY6 | 2.28 | 6" Sloped Curb |
| CHY8 | 1.33 | 8" Channelizing Line | LDW8 | 0.33 | 8" Lane Drop Line | STW6 | 2.03 | 6" Standard Curb |
| CLW6 | 2.00 | Crosswalk Line | MNY6 | 1.00 | Median nose | STY6 | 2.03 | 6" Standard Curb |
| DCY4 | 1.34 | 4" Double Centerline | NPY4 | 0.84 | 4" No Passing Zone | YLW2 | 1.15 | Yield Line |
| DCY6 | 2.00 | 6" Double Centerline | NPY6 | 1.25 | 6" No Passing Zone | |||
| DDY4 | 0.44 | 4" Double Dotted Line | RLW4 | 0.67 | 4" Ramp Edge Line | |||
| DDY6 | 0.67 | 6" Double Dotted Line | RLW6 | 1.00 | 6" Ramp Edge Line |
Factors can be calculated by:
- Factor = (PL/RL)X(LW/6)
- PL = Painted Length
- RL = Repeat Length
- LW = Line Width