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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