Difference between revisions of "Pavement Markings"
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Longitudinal Markings are line type markings that delineate travel lanes and are parallel to vehicle direction. They are various widths and can be solid or dashed at various lengths. All lines on MDOT roads are retroreflective with the exception of parking lot markings. | Longitudinal Markings are line type markings that delineate travel lanes and are parallel to vehicle direction. They are various widths and can be solid or dashed at various lengths. All lines on MDOT roads are retroreflective with the exception of parking lot markings. | ||
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| + | ==[[#'''Special Markings'''|'''Special Markings''']]== | ||
| + | ===[[#Types|Types]]=== | ||
| + | Special markings (referred to as "transverse markings" in the MMUTCD) include shoulder markings, word and symbol markings, arrows, stop lines (stop bars), yield lines, crosswalk lines, speed measurement markings, speed reduction markings, speed hump markings, parking space markings, and others. Special markings are generally white but in certain cases may match the color of the nearest edge line or include contrasting colors. | ||
| + | (Based on 2011 MMUTCD, Section 3B.15) | ||
| + | |||
| + | ===[[#Applications|Applications]]=== | ||
| + | The applications of special pavement markings are more varied than those for longitudinal pavement markings. Special markings can be used to guide, warn, or regulate both vehicular and pedestrian traffic. Some of the more commonly used special markings are detailed below. | ||
| + | |||
| + | * '''Stop Bar Markings''' indicate the point behind which vehicles are required to stop in compliance with a traffic control signal. They may also be used in conjunction with stop signs, but it is not MDOT policy to do so unless an intersection requires additional emphasis. Stop bars on MDOT trunkline are 24 inches in width, but many local agencies use 18 inch width on their roadways. | ||
| + | |||
| + | * '''Yield Lines''' come in two designs and are used to indicate the point behind which vehicles are required to yield in compliance with a “Yield†sign or a “Yield Here to Pedestrians†sign. While not frequently used in Michigan the lines comprised of triangles (also known as “shark teethâ€) are installed in advance of unsignalized midblock pedestrian crossings that span more than two lanes. The other type of yield line is present at the entry to the circular roadway of a roundabout, and consists of 12-inch wide striping in a pattern of 3 feet of marking followed by 3 feet of gap. | ||
| + | |||
| + | * '''Crosswalk Markings''' provide guidance for pedestrians who are crossing roadways by defining and delineating their path, and can also serve to alert motorists of the pedestrian crossing. Standard crosswalk markings used at signalized or stop-controlled intersection legs consist of two parallel 6 inch lines placed transverse to the flow of vehicular traffic. Special emphasis crosswalk markings consist of 12 inch bars placed parallel to vehicular traffic and separated by a 24 inch space. Special emphasis markings are used over the standard crosswalk markings at midblock crossing locations, established school crossings, and where pedestrians must cross vehicular traffic that does not stop. See "Guidance for Installation of Pedestrian Crosswalks on Michigan State Trunkline Highways" on the MDOT Traffic & Safety website for more information. | ||
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| + | * '''Word and Symbol Markings''' can be helpful to road users in some locations by supplementing signs and providing additional emphasis for important regulatory, warning, or guidance messages, because the markings do not require diversion of the road user’s attention from the roadway surface. These include legends, arrows, accessible symbols, route shield markings, and more. Most arrows and legends are detailed in the current version of Pavement Marking Standard PAVE-900. | ||
Revision as of 12:46, 10 July 2017
Overview
Functions and Limitations
Markings on highways and on private roads open to public travel have important functions in providing guidance and information for the road user. Major marking types include pavement and curb markings, delineators, colored pavements, channelizing devices, and islands. In some cases, markings are used to supplement other traffic control devices such as signs, signals, and other markings. In other instances, markings are used alone to effectively convey regulations, guidance, or warnings in ways not obtainable by the use of other devices. Markings have limitations. Visibility of the markings can be limited by snow, debris, and water on or adjacent to the markings. Marking durability is affected by material characteristics, traffic volumes, weather, and location. However, under most highway conditions, markings provide important information while allowing minimal diversion of attention from the roadway.
2011 MMUTCD, Section 3A.01
Initiatives
Optical Speed Bars Optical speed bars are white transverse markings on both sides of the lane that are placed at decreasing spacing in the direction of travel to give drivers the sense that they are traveling at a higher rate of speed to encourage slowing down. Previous installations in Michigan include EB I-94 Exit 12 (Sawyer Rd) in Sawyer and WB US-10 Business Route at M-20 in Midland.
Preformed Thermoplastic Route Shields
Preformed thermoplastic route shields are large markings in the lane that identify lane use ahead of a split or other confusing geometry. Previous installations in Michigan include the SB I-75/US-23 split in Flint and the diverging diamond interchange (DDI) at I-96 at Cascade Rd near Grand Rapids.
Curb/Island Painting
Curb/island painting is pavement marking material, including beads, that is applied to curb and raised island surfaces to provide positive guidance to traffic.
Delineator Pilot Project
A pilot project was initiated in late 2014 in cooperation with the Lansing TSC and the Charlotte Garage to evaluate alternatives to standard post mounted plastic buttons and enhanced guardrail options. The pilot project covers approximately 8 miles of NB and SB I-69 in the Charlotte area.
Sinusoidal Rumble Strips
Sinusoidal rumble strips, or “mumble strips†are a rolling sine wave pattern that is slightly recessed into the pavement surface. Sinusoidal rumble strips provide adequate sound and vibration to the driver but produce less exterior noise than traditional rumble strips. Different patterns are currently installed in Minnesota, Pennsylvania and California. MDOT is exploring the installation of a pilot section.
Statewide Rumble Strip Installation and Research
From 2008-2010, MDOT performed a statewide installation of centerline rumble strips on all appropriate non-freeway roads. The research project that followed took place in two phases. Phase 1 studied the impacts of rumble strips on driver behavior and Phase 2 studied the impact of rumble strips on crashes. A significant finding of phase 2 is that centerline rumble strips resulted in a 51% reduction in fatal lane departure crashes. Both reports can be found here:
RC-1575 - Impact of Non-Freeway Rumble Strips - Phase 1
RC-1627 - Evaluation of Non-Freeway Rumble Strips - Phase II
Ongoing Pavement Marking Research Project
An ongoing pavement marking research project is evaluating current pavement marking practices in Michigan and other states to identify best practices for increased program efficiency. The research project will conclude in Spring of 2017.
Innovative Materials
As new materials are developed, MDOT seeks to evaluate them for cost effectiveness, durability, wet night retroreflectivity, and speed of installation. It is important to evaluate both products that are competitors to existing products and brand new products that have never been tried in the state before. An example of a material that has been recently tested in Michigan is structured methyl methacrylate.
Wrong-Way Movement Treatments
PAVE-926 was created to help address wrong way movements at partial cloverleaf interchanges. The standard shows optional and required pavement marking and delineation treatments.
Longitudinal Markings
Types
The general functions of longitudinal lines shall be:
A. A double line indicates maximum or special restrictions
B. A solid line discourages or prohibits crossing (depending on specific application)
C. A broken line indicates a permissive condition, and
D. A dotted line provides guidance or warning or a downstream change in lane function.
The widths and patterns of longitudinal lines shall be:
A. Normal line - 4 to 6 inches wide.
B. Wide line - at least twice the width of a normal line.
C. Double line - two parallel lines separated by a discernible space.
D. Broken line - normal line segments separated by gaps
E. Dotted line - noticeably shorter line segments separated by shorter gaps than used for a broken line. The width of the dotted line extension shall be at least the same as the width of the line it extends.
2011 MMUTCD Section 3A.06
- Information regarding patterns and widths longitudinal markings used on MDOT roads can be found in the most recent version of PAVE-905
Applications
Longitudinal Markings are line type markings that delineate travel lanes and are parallel to vehicle direction. They are various widths and can be solid or dashed at various lengths. All lines on MDOT roads are retroreflective with the exception of parking lot markings.
Special Markings
Types
Special markings (referred to as "transverse markings" in the MMUTCD) include shoulder markings, word and symbol markings, arrows, stop lines (stop bars), yield lines, crosswalk lines, speed measurement markings, speed reduction markings, speed hump markings, parking space markings, and others. Special markings are generally white but in certain cases may match the color of the nearest edge line or include contrasting colors. (Based on 2011 MMUTCD, Section 3B.15)
Applications
The applications of special pavement markings are more varied than those for longitudinal pavement markings. Special markings can be used to guide, warn, or regulate both vehicular and pedestrian traffic. Some of the more commonly used special markings are detailed below.
- Stop Bar Markings indicate the point behind which vehicles are required to stop in compliance with a traffic control signal. They may also be used in conjunction with stop signs, but it is not MDOT policy to do so unless an intersection requires additional emphasis. Stop bars on MDOT trunkline are 24 inches in width, but many local agencies use 18 inch width on their roadways.
- Yield Lines come in two designs and are used to indicate the point behind which vehicles are required to yield in compliance with a “Yield†sign or a “Yield Here to Pedestrians†sign. While not frequently used in Michigan the lines comprised of triangles (also known as “shark teethâ€) are installed in advance of unsignalized midblock pedestrian crossings that span more than two lanes. The other type of yield line is present at the entry to the circular roadway of a roundabout, and consists of 12-inch wide striping in a pattern of 3 feet of marking followed by 3 feet of gap.
- Crosswalk Markings provide guidance for pedestrians who are crossing roadways by defining and delineating their path, and can also serve to alert motorists of the pedestrian crossing. Standard crosswalk markings used at signalized or stop-controlled intersection legs consist of two parallel 6 inch lines placed transverse to the flow of vehicular traffic. Special emphasis crosswalk markings consist of 12 inch bars placed parallel to vehicular traffic and separated by a 24 inch space. Special emphasis markings are used over the standard crosswalk markings at midblock crossing locations, established school crossings, and where pedestrians must cross vehicular traffic that does not stop. See "Guidance for Installation of Pedestrian Crosswalks on Michigan State Trunkline Highways" on the MDOT Traffic & Safety website for more information.
- Word and Symbol Markings can be helpful to road users in some locations by supplementing signs and providing additional emphasis for important regulatory, warning, or guidance messages, because the markings do not require diversion of the road user’s attention from the roadway surface. These include legends, arrows, accessible symbols, route shield markings, and more. Most arrows and legends are detailed in the current version of Pavement Marking Standard PAVE-900.