Pavement Markings

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.

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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.

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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 teeth”) 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.

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Restriping

Responsible Parties

Intersections, interchanges, on-street parking

Contract Cycle

Every year, 85%-90% of the long line markings on MDOT roads are restriped totaling nearly 155-160 million feet of material. In addition, approximately 25% of special markings on MDOT roads are replaced each year.

Recently, marking replacement contracts have been consolidated from TSCs to region wide. Presently, each region has one special marking contract and one long line contract per year. In the past, the number of contracts has varied from year to year, depending whether contracts were submitted from the region or TSC level.

Most regions replace special markings on a 4 year cycle. When using cold plastic, the material can be place two layers thick ((initial application plan an overlay 4 years later) before requiring full removal. Polyurea does not need full removal, but requires the existing layer of material to be scarified prior to placing the next.

There can be some variation in the size of both types of contracts from year to year based a few different factors. Long line contracts can vary due to the size of the year’s construction program and the replacement of aging durables. Special marking contracts vary due to whether markings are in need of full removal and replacement or just overlay. An allowance for callback work is added to each contract to account for replacement of materials that unexpectedly need to be replaced or were in inadvertently left out.

Contact Development

Contract templates are being developed for both types of contracts in order to promote consistency between the regions. Contracts are not plan-based, but are completed as log projects instead. A statewide pavement marking database for both long lines and special markings maintained in MS Access is housed on MDOT’s ProjectWise program.

Role overview (Region vs. Lansing Responsibilities)

Regions maintain their own log information and prepare contract documents and then submit to Lansing Pavement Marking area for review prior to submission to Specifications and Estimates.

Schedule

In late summer/early fall, Lansing Pavement Marking Area develops rough contract cost estimates for all 14 contracts (7 regions, 2 contracts each) and then divides the projects into 3 lettings (February, March and April) based on roughly equal total cost per letting. Lansing then programs projects in MPINS and then sends emails to regions with information needed to start developing their contracts. Information included in these emails includes job number, miscellaneous notes, pay item unit process, etc. Regions then begin to develop their contracts in order to prepare for reviews with Lansing starting in December.

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