Part 1. General
CHAPTER 1A. GENERAL
Section 1A.01 Purpose of Traffic Control
Devices
Support:
The purpose of traffic control devices, as well as the principles for
their use, is to promote highway safety and efficiency by providing for
the orderly movement of all road users on streets and highways throughout
the Nation.
Traffic control devices notify road users of regulations
and provide warning and guidance needed for the safe, uniform, and efficient
operation of all elements of the traffic stream.
Standard:
Traffic control devices or their supports shall not bear any advertising
message or any other message that is not related to traffic control.
Support:
Tourist-oriented directional signs and Specific Service signs are not
considered advertising; rather, they are classified as motorist service
signs.
Section 1A.02 Principles
of Traffic Control Devices
Support:
This Manual contains the basic principles that govern the design and use
of traffic control devices for all streets and highways open to public
travel regardless of type or class or the public agency having jurisdiction.
This Manual's text specifies the restriction on the use of a device if
it is intended for limited application or for a specific system. It is
important that these principles be given primary consideration in the
selection and application of each device.
Guidance:
To be effective, a traffic control device should meet five basic requirements:
- Fulfill a need;
- Command attention;
- Convey a clear, simple meaning;
- Command respect from road users; and
- Give adequate time for proper response.
The following aspects of traffic control devices should
be considered to ensure that the above criteria are met: design; placement
and operation; maintenance; and uniformity. Vehicle speed should be carefully
considered as an element that governs the design, operation, placement,
and location of various traffic control devices.
Support:
The definition of the word "speed" varies depending on its use. The definitions
of specific speed terms are contained in Section 1A.13.
Guidance:
The actions required of road users to obey regulatory devices should be
specified by State statute, or in cases not covered by State statute,
by local ordinance or resolution consistent with the "Uniform Vehicle
Code."
The proper use of traffic control devices should provide
the reasonable and prudent road user with the information necessary to
safely and lawfully use the streets, highways, pedestrian facilities,
and bikeways.
Support:
Uniformity of the meaning of traffic control devices is vital to their
effectiveness. The meanings ascribed to devices in this Manual are in
general accord with the documents mentioned in Section 1A.11.
Section 1A.03 Design
of Traffic Control Devices
Guidance:
Devices should be designed so that features such as size, shape, and color,
composition, lighting or retroreflection, and contrast are combined to
draw attention to the devices; that size, shape, color, and simplicity
of message combine to produce a clear meaning; that legibility and size
combine with placement to permit adequate time for response; and that
uniformity, size, legibility, and reasonableness of the message combine
to command respect.
Standard:
All adopted symbol signs are shown in the "Standard Highway Signs" book
(see Section 1A.11). All symbols and colors for signs not shown in the
"Standard Highway Signs" book shall follow the procedures for experimentation
and change described in Section 1A.10. All symbols shall be unmistakably
similar to or mirror images of those shown herein. Symbols and colors
shall not be modified unless otherwise stated herein.
Guidance:
Aspects of a device's design should be modified only if there is demonstrated
need.
Support:
An example of modifying a device's design would be to modify the Side
Road (W2-2) sign to show a second offset intersecting road.
Option:
Highway agencies may develop word message signs to notify road users of
special regulations or to warn road users of a situation that may not
be readily apparent. Unlike symbol signs and colors, new word message
signs may be used without the need for experimentation. With the exception
of symbols and colors, minor modifications in the specific design elements
of a device may be made provided the essential appearance characteristics
are preserved. Although the standard design of symbol signs cannot be
modified, it may be appropriate to change the orientation of the symbol
to better reflect the direction of travel.
Return to Part 1 Table of Contents
Section 1A.04 Placement
and Operation of Traffic Control Devices
Guidance:
Placement of a traffic control device should be within the road user's
view so that maximum visual acuity is provided. To aid in conveying the
proper meaning, the traffic control device should be appropriately positioned
with respect to the location, object, or situation to which it applies.
The location and legibility of the traffic control device should be such
that a road user has adequate time to make the proper response in both
day and night conditions.
Traffic control devices should be placed and operated
in a uniform and consistent manner.
Unnecessary traffic control devices should be removed.
The fact that a device is in good physical condition should not be a basis
for deferring needed removal or change.
Section 1A.05 Maintenance
of Traffic Control Devices
Guidance:
Functional maintenance of traffic control devices should be used to determine
if certain devices need to be changed to meet current traffic conditions.
Physical maintenance of traffic control devices should
be performed to ensure that legibility is retained, that the device is
visible, and that it functions properly in relation to other traffic control
devices in the vicinity.
Traffic control devices should be reviewed periodically
to determine if they meet current traffic conditions.
Traffic control devices should be maintained to ensure
that legibility is retained, that the device is visible, and that it functions
properly in relation to other traffic control devices in the vicinity
during both day and night conditions.
Support:
Clean, legible, properly mounted devices in good working condition command
the respect of road users.
Section 1A.06 Uniformity
of Traffic Control Devices
Support:
Uniformity of devices simplifies the task of the road user because it
aids in recognition and understanding, thereby reducing perception/reaction
time. Uniformity assists road users, police officers, and traffic courts
by giving everyone the same interpretation. Uniformity assists public
highway officials through efficiency in manufacture, installation, maintenance,
and administration. Uniformity means treating similar situations in a
similar way. The use of uniform traffic control devices does not, in itself,
constitute uniformity. A standard device used where it is not appropriate
is as objectionable as a nonstandard device; in fact, this might be worse,
because such misuse might result in disrespect at those locations where
the device is needed and appropriate.
Section 1A.07 Responsibility
for Traffic Control Devices
Standard:
The responsibility for the design, placement, operation, maintenance,
and uniformity of traffic control devices shall rest with the public agency
or the official having jurisdiction. 23 CFR 655.603 adopts the Manual
on Uniform Traffic Control Devices as the national standard for all traffic
control devices installed on any street, highway, or bikeway open to public
travel. When a State or other Federal agency manual or supplement is required,
they shall be in substantial conformance with the national Manual on Uniform
Traffic Control Devices.
23 CFR 655.603 also states that traffic control devices
on all streets and highways open to public travel in each State shall
be in substantial conformance with standards issued or endorsed by the
Federal Highway Administrator.
Support:
The "Uniform Vehicle Code" (see Section 1A.11) has the following provision
in Section 15-104 for the adoption of a uniform Manual:
"(a)The [State Highway Agency] shall adopt a manual
and specification for a uniform system of traffic control devices consistent
with the provisions of this code for use upon highways within this State.
Such uniform system shall correlate with and so far as possible conform
to the system set forth in the most recent edition of the Manual on
Uniform Traffic Control Devices for Streets and Highways, and other
standards issued or endorsed by the Federal Highway Administrator."
"(b) The Manual adopted pursuant to subsection (a)
shall have the force and effect of law."
Additionally, States are encouraged to adopt Section
15-117 of the "Uniform Vehicle Code," which states that, "No person shall
install or maintain in any area of private property used by the public
any sign, signal, marking or other device intended to regulate, warn,
or guide traffic unless it conforms with the State manual and specifications
adopted under Section 15-104."
Section 1A.08 Authority
for Placement of Traffic Control Devices
Standard:
Traffic control devices, advertisements, announcements, and other signs
or messages within the highway right-of-way shall be placed only as authorized
by a public authority or the official having jurisdiction, for the purpose
of regulating, warning, or guiding traffic.
When the public agency or the official having jurisdiction
over a street or highway has granted proper authority, others such as
contractors and public utility companies shall be permitted to install
temporary traffic control devices in temporary traffic control zones.
Such traffic control devices shall conform with the Standards of this
Manual.
Guidance:
Any unauthorized traffic control device or other sign or message placed
on the highway right-of-way by a private organization or individual constitutes
a public nuisance and should be removed. All unofficial or nonessential
traffic control devices, signs, or messages should be removed.
Standard:
All regulatory traffic control devices shall be supported by laws, ordinances,
or regulations.
Support:
Provisions of this Manual are based upon the concept that effective traffic
control depends upon both appropriate application of the devices and reasonable
enforcement of the regulations.
Section 1A.09 Engineering
Study and Engineering Judgment
Standard:
This Manual describes the application of traffic control devices, but
shall not be a legal requirement for their installation.
Guidance:
The decision to use a particular device at a particular location should
be made on the basis of either an engineering study or the application
of engineering judgment. Thus, while this Manual provides Standards, Guidance,
and Options for design and application of traffic control devices, this
Manual should not be considered a substitute for engineering judgment.
Engineering judgment should be exercised in the selection
and application of traffic control devices, as well as in the location
and design of the roads and streets that the devices complement. Jurisdictions
with responsibility for traffic control that do not have engineers on
their staffs, should seek engineering assistance from others, such as
the State transportation agency, their county, a nearby large city, or
a traffic engineering consultant.
Return to Part 1 Table of Contents
Section 1A.10 Interpretations,
Experimentations, and Changes
Standard:
Design, application, and placement of traffic control devices other than
those adopted in this Manual shall be prohibited unless the provisions
of this Section are followed.
Support:
Continuing advances in technology will produce changes in the highway,
vehicle, and road user proficiency; therefore, portions of the system
of traffic control devices in this Manual will require updating. In addition,
unique situations often arise for device applications that might require
interpretation or clarification of this Manual. It is important to have
a procedure for recognizing these developments and for introducing new
ideas and modifications into the system.
Guidance:
Requests for any interpretation, permission to experiment, or change should
be sent to the Federal Highway Administration (FHWA), Office of Transportation
Operations, 400 Seventh Street SW, HOTO, Washington, DC 20590.
Support:
An interpretation includes a consideration of the application and operation
of standard traffic control devices, official meanings of standard traffic
control devices, or the variations from standard device designs.
Guidance:
Requests for an interpretation of this Manual should contain the following
information:
- A concise statement of the interpretation being
sought;
- A description of the condition that provoked
the need for a revised interpretation;
- Any illustration that would be helpful to understand
the request; and
- Any supporting research data that is pertinent
to the item to be interpreted.
Support:
Requests to experiment include consideration of testing or evaluating
a new traffic control device, its application or manner of use, or a provision
not specifically described in this Manual.
A request for permission to experiment will be considered
only when submitted by the public agency or private toll facility responsible
for the operation of the road or street on which the experiment is to
take place.
A diagram indicating the process for experimenting with
traffic control devices is shown in Figure 1A-1.
Figure
1A-1 Typical Process for Requesting and Conducting Experimentations
for New Traffic Control Devices [D]
Guidance:
The request for permission to experiment should contain the following:
- A statement indicating the nature of the problem.
- A description of the proposed change to the
traffic control device or application of the traffic control device,
how it was developed, the manner in which it deviates from the standard,
and how it is expected to be an improvement over existing standards.
- Any illustration that would be helpful to understand
the traffic control device or use of the traffic control device.
- Any supporting data explaining how the traffic
control device was developed, if it has been tried, in what ways it
was found to be adequate or inadequate, and how this choice of device
or application was derived.
- A legally binding statement certifying that
the traffic control device is not protected by a patent or copyright.
- The time period and location(s) of the experiment.
- A detailed research or evaluation plan that
must provide for close monitoring of the experimentation, especially
in the early stages of its field implementation. The evaluation plan
should include before and after studies as well as quantitative data
describing the performance of the experimental device.
- An agreement to restore the site of the experiment
to a condition that complies with the provisions of this Manual within
3 months following the end of the time period of the experiment. This
agreement must also provide that the agency sponsoring the experimentation
will terminate the experimentation at any time that it determines significant
safety concerns are directly or indirectly attributable to the experimentation.
The FHWA's Office of Transportation Operations has the right to terminate
approval of the experimentation at any time if there is an indication
of safety concerns. If, as a result of the experimentation, a request
is made that this Manual be changed to include the device or application
being experimented with, the device or application will be permitted
to remain in place until an official rulemaking action has occurred.
- An agreement to provide semiannual progress
reports for the duration of the experimentation, and an agreement to
provide a copy of the final results of the experimentation to the FHWA's
Office of Transportation Operations within 3 months following completion
of the experimentation. The FHWA's Office of Transportation Operations
has the right to terminate approval of the experimentation if reports
are not provided in accordance with this schedule.
Support:
A change includes consideration of a new device to replace a present standard
device, an additional device to be added to the list of standard devices,
or a revision to a traffic control device application or placement criteria.
Guidance:
Requests for a change to this Manual should contain the following information:
- A statement indicating what change is proposed;
- Any illustration that would be helpful to understand
the request; and
- Any supporting research data that is pertinent
to the item to be reviewed.
Support:
A diagram indicating the process for requesting changes to this Manual
is shown in Figure 1A-2.
Figure
1A-2 Typical Process for Incorporating New Traffic Control Devices
into the MUTCD [D]
Procedures for revising this Manual are set out in the Federal Register
of June 30, 1983 (48 FR 30145).
For additional information concerning interpretations,
experimentation, or changes, write to the FHWA, 400 Seventh Street, SW,
HOTO, Washington, DC 20590, or visit the MUTCD
website.
Section 1A.11 Relation
to Other Documents
Standard:
To the extent that they are incorporated by specific reference, the latest
editions of the following documents, or those editions specifically noted,
shall be a part of this Manual: "Standard Alphabets for Highway Signs
and Pavement Markings," 1977 Edition (FHWA); "Standard Alphabets for Highway
Signs," 1966 Edition (FHWA); "Standard Color Tolerance Limits," (FHWA);
and "Standard Highway Signs," 1979 Edition (FHWA).
Support:
For ordering information for the above publications, visit the Federal
Highway Administration's MUTCD website,
or write to the FHWA, 400 Seventh Street, SW, HOTO, Washington, DC 20590.
The latest version of other documents that are useful
sources of information with respect to use of this Manual are listed below.
- "Vehicle Traffic Control Signal Heads," Part
1—1985 Edition; Part 2—1998 Edition(Institute of Transportation
Engineers—ITE)
- "Pedestrian Traffic Control Signal Indications,"
1985 Edition (ITE)
- "Purchase Specification for Flashing and Steady
Burn Warning Lights," 1981 Edition (ITE)
- "Traffic Signal Lamps," 1980 Edition (ITE)
- "Uniform Vehicle Code (UVC) and Model Traffic
Ordinance," 1992 Edition (National Committee on Uniform Traffic Laws
and Ordinances)
- "Traffic Engineering Handbook," 1999 Edition
(ITE)
- "Highway Capacity Manual," 1998 Edition (Transportation
Research Board—TRB)
- "A Policy on Geometric Design of Highway and
Streets," 1994 Edition (American Association of State Highway and Transportation
Officials—AASHTO)
- "Guidelines for the Selection of Supplemental
Guide Signs for Traffic Generators Adjacent to Freeways," 1993 Edition
(AASHTO)
- "List of Control Cities for Use in Guide Signs
on Interstate Highways," 1993 Edition (AASHTO)
- "Manual of Transportation Engineering Studies,"
1994 Edition (ITE)
- "Roadside Design Guide," 1996 Edition (AASHTO)
- "School Trip Safety Program Guidelines,"1984
Edition (ITE)
- "Manual of Traffic Signal Design," 1991 Edition
(ITE)
- "Traffic Detector Handbook," 1991 Edition (ITE)
- "2000 AREMA Communications & Signals Manual,"
American Railway Engineering & Maintenance-of-Way Association(AREMA)
- "Preemption of Traffic Signals at or Near Railroad
Grade Crossings with Active Warning Devices," (ITE)
- "Highway-Rail Intersection Architecture," U.S.
Department of Transportation, Federal Railroad Administration (USDOT/FRA)
- "Practice for Roadway Lighting," RP-8, 1983,
Illuminating Engineering Society (IES)
- "Safety Guide for the Prevention of Radio Frequency
Radiation Hazards in the Use of Commercial Electric Detonators(Blasting
Caps)," Safety Library Publication No. 20, Institute of Makers of Explosives
- "Accessible Pedestrian Signals, "
A-37, U.S. Architectural and Transportation Barriers Compliance Board
(The U.S. Access Board)
Section 1A.12 Color
Code
Support:
The following color code establishes general meanings for 9 colors of
a total of 12 colors that have been identified as being appropriate for
use in conveying traffic control information. Central values and tolerance
limits for each color are available from the Federal Highway Administration,
400 Seventh Street, SW, HOTO, Washington, DC 20590, and at FHWA's MUTCD
website.
The three colors for which general meanings have not
yet been assigned are being reserved for future applications that will
be determined only by FHWA after consultation with the States, the engineering
community, and the general public. The meanings described in this Section
are of a general nature. More specific assignments of colors are given
in the individual Parts of this Manual relating to each class of devices.
Standard:
The general meaning of the 12 colors shall be as follows:
- Yellow—warning
- Red—stop or prohibition
- Blue—road user services guidance, tourist
information, and evacuation route
- Green—indicated movements permitted,
direction guidance
- Brown—recreational and cultural interest
area guidance
- Orange—temporary traffic control
- Black—regulation
- White—regulation
- Fluorescent Yellow-Green—pedestrian
warning, bicycle warning, school bus and school warning
- Purple—unassigned
- Light Blue—unassigned
- Coral—unassigned
Return to Part 1 Table of Contents
Section 1A.13 Definitions
of Words and Phrases in This Manual
Standard:
Unless otherwise defined herein, or in the other Parts of this Manual,
definitions contained in the most recent edition of the "Uniform Vehicle
Code," "AASHTO Transportation Glossary (Highway Definitions)," and other
documents specified in Section 1A.11 are also incorporated and adopted
by reference.
The following words and phrases, when used in this Manual,
shall have the following meanings:
- Active Grade Crossing Warning System—the
flashing-light signals, with or without warning gates, together with
the necessary control equipment used to inform road users of the approach
or presence of trains at highway-rail grade crossings.
- Approach—all lanes of traffic moving
towards an intersection or a midblock location from one direction, including
any adjacent parking lane(s).
- Arterial Highway (Street)—a general
term denoting a highway primarily used by through traffic, usually on
a continuous route or a highway designated as part of an arterial system.
- Average Day—a day representing traffic
volumes normally and repeatedly found at a location, typically a weekday
when volumes are influenced by employment or a weekend when volumes
are influenced by entertainment or recreation.
- Beacon—a highway traffic signal with
one or more signal sections that operates in a flashing mode.
- Bicycle—a pedal-powered vehicle upon
which the human operator sits.
- Bicycle Lane—a portion of a roadway
that has been designated by signs and pavement markings for preferential
or exclusive use by bicyclists.
- Centerline Markings—the yellow pavement
marking line(s) that delineates the separation of traffic lanes that
have opposite directions of travel on a roadway. These markings need
not be at the geometrical center of the pavement.
- Changeable Message Signs—signs that
are capable of displaying more than one message, changeable manually,
by remote control, or by automatic control. These signs are referred
to as Dynamic Message Signs in the National Intelligent Transportation
Systems (ITS) Architecture.
- Channelizing Line Marking—a wide or
double solid white line used to form islands where traffic in the same
direction of travel is permitted on both sides of the island.
- Circular Intersection—an intersection
that has an island, generally circular in design, located in the center
of the intersection where traffic passes to the right of the island.
Circular intersections include roundabouts, rotaries, and traffic circles.
- Clear Zone—the total roadside border
area, starting at the edge of the traveled way, that is wide enough
to allow an errant driver to stop or regain control of a vehicle. This
area might consist of a shoulder, a recoverable slope, and/or a nonrecoverable,
traversable slope with a clear run-out area at its toe.
- Concurrent Flow HOV Lane—an HOV lane
that is operated in the same direction as the adjacent mixed flow lanes,
separated from the adjacent general purpose freeway lanes by a standard
lane stripe, painted buffer, or barrier.
- Contraflow Lane—a lane operating in
a direction opposite to the normal flow of traffic designated for peak
direction of travel during at least a portion of the day. Contraflow
lanes are usually separated from the off-peak direction lanes by plastic
pylons, or by moveable or permanent barrier.
- Conventional Road—a street or highway
other than a low-volume road (as defined in Section 5A.01), expressway,
or freeway.
- Collector Highway—a term denoting a
highway that in rural areas connects small towns and local highways
to arterial highways, and in urban areas provides land access and traffic
circulation within residential, commercial and business areas and connects
local highways to the arterial highways.
- Crosswalk—(a) that part of a roadway
at an intersection included within the connections of the lateral lines
of the sidewalks on opposite sides of the highway measured from the
curbs or in the absence of curbs, from the edges of the traversable
roadway, and in the absence of a sidewalk on one side of the roadway,
the part of a roadway included within the extension of the lateral lines
of the sidewalk at right angles to the centerline; (b) any portion of
a roadway at an intersection or elsewhere distinctly indicated for pedestrian
crossing by lines or other markings on the surface.
- Crosswalk Lines—white pavement marking
lines that identify a crosswalk.
- Delineators—retroreflective devices
mounted on the roadway surface or at the side of the roadway in a series
to indicate the alignment of the roadway, especially at night or in
adverse weather.
- Dynamic Envelope—the clearance required
for the train and its cargo overhang due to any combination of loading,
lateral motion, or suspension failure.
- EdgeLine Markings—white or yellow pavement
marking lines that delineate the right or left edge(s) of a traveled
way.
- End-of-Roadway Marker—a device used
to warn and alert road users of the end of a roadway in other than temporary
traffic control zones.
- Engineering Judgment—the evaluation
of available pertinent information, and the application of appropriate
principles, Standards, Guidance, and practices as contained in this
Manual and other sources, for the purpose of deciding upon the applicability,
design, operation, or installation of a traffic control device. Engineering
judgment shall be exercised by an engineer, or by an individual working
under the supervision of an engineer, through the application of procedures
and criteria established by the engineer. Documentation of engineering
judgment is not required.
- Engineering Study—the comprehensive
analysis and evaluation of available pertinent information, and the
application of appropriate principles, Standards, Guidance, and practices
as contained in this Manual and other sources, for the purpose of deciding
upon the applicability, design, operation, or installation of a traffic
control device. An engineering study shall be performed by an engineer,
or by an individual working under the supervision of an engineer, through
the application of procedures and criteria established by the engineer.
An engineering study shall be documented.
- Expressway—a divided highway with partial
control of access.
- Flashing (Flashing Mode)—a mode of
operation in which a traffic signal indication is turned on and off
repetitively.
- Freeway—a divided highway with full
control of access.
- Guide Sign—a sign that shows route
designations, destinations, directions, distances, services, points
of interest, or other geographical, recreational, or cultural information.
- High Occupancy Vehicle (HOV)—a motor
vehicle carrying at least two or more persons, including carpools, vanpools,
and buses.
- Highway—a general term for denoting
a public way for purposes of travel by vehicular travel, including the
entire area within the right-of-way.
- Highway-Rail Grade Crossing—the general
area where a highway and a railroad's right-of-way cross at the same
level, within which are included the railroad tracks, highway, and traffic
control devices for highway traffic traversing that area.
- Highway Traffic Signal—a power-operated
traffic control device by which traffic is warned or directed to take
some specific action. These devices do not include power-operated signs,
illuminated pavement markers, barricade warning lights, or steady burning
electric lamps.
- HOV Lane—any preferential lane designated
for exclusive use by high-occupancy vehicles for all or part of a day—including
a designated lane on a freeway, other highway, street, or independent
roadway on a separate right-of-way.
- Interchange—a system of interconnecting
roadways providing for traffic movement between two or more highways
that do not intersect at grade.
- Intermediate Interchange—an interchange
with an urban or rural route that is not a major or minor interchange
as defined herein.
- Intersection—(a) the area embraced
within the prolongation or connection of the lateral curb lines, or
if none, the lateral boundary lines of the roadways of two highways
that join one another at, or approximately at, right angles, or the
area within which vehicles traveling on different highways that join
at any other angle may come into conflict; (b) the junction of an alley
or driveway with a roadway or highway shall not constitute an intersection.
- Island—a defined area between traffic
lanes for control of vehicular movements or for pedestrian refuge. It
includes all end protection and approach treatments. Within an intersection
area, a median or an outer separation is considered to be an island.
- Lane Line Markings—white pavement marking
lines that delineate the separation of traffic lanes that have the same
direction of travel on a roadway.
- Lane-Use Control Signal—a signal face
displaying indications to permit or prohibit the use of specific lanes
of a roadway or to indicate the impending prohibition of such use.
- Legend—see Sign Legend.
- Logo—a distinctive emblem, symbol,
or trademark that identifies a product or service.
- Longitudinal Markings—pavement markings
that are generally placed parallel and adjacent to the flow of traffic
such as lane lines, centerlines, edge lines, channelizing lines, and
others.
- Major Interchange—an interchange with
another freeway or expressway, or an interchange with a high-volume
multilane highway, principal urban arterial, or major rural route where
the interchanging traffic is heavy or includes many road users unfamiliar
with the area.
- Major Street—the street normally carrying
the higher volume of vehicular traffic.
- Median—the area between two roadways
of a divided highway measured from edge of traveled way to edge of traveled
way. The median excludes turn lanes. The median width might be different
between intersections, interchanges, and at opposite approaches of the
same intersection.
- Minor Interchange—an interchange where
traffic is local and very light, such as interchanges with land service
access roads. Where the sum of the exit volumes is estimated to be lower
than 100 vehicles per day in the design year, the interchange is classified
as local.
- Minor Street—the street normally carrying
the lower volume of vehicular traffic.
- Object Markers—devices used to mark
obstructions within or adjacent to the roadway.
- Occupancy Requirement—any restriction
that regulates the use of a facility for any period of the day based
on a specified number of persons in a vehicle.
- Occupants—the people driving or riding
in a car, truck, bus, or other vehicle.
- Paved—a bituminous surface treatment,
mixed bituminous concrete, or Portland cement concrete roadway surface
that has both a structural (weight bearing) and a sealing purpose for
the roadway.
- Pedestrian—a person afoot, in a wheelchair,
on skates, or on a skateboard.
- Platoon—a group of vehicles or pedestrians
traveling together as a group, either voluntarily or involuntarily,
because of traffic signal controls, geometrics, or other factors.
- Preferential Lane Marking—white lines
formed in a diamond shape.
- Principal Legend—place names, street
names, and route numbers placed on guide signs.
- Public Road—any road or street under
the jurisdiction of and maintained by a public agency and open to public
travel.
- Raised Pavement Marker—a device with
a height of at least 10 mm (0.4 in) mounted on or in a road surface
and intended to supplement or substitute for pavement markings.
- Regulatory Signs—a sign that gives
notice to road users of traffic laws or regulations.
- Retroreflectivity—a property of a surface
that allows a large portion of the light coming from a point source
to be returned directly back to a point near its origin.
- Right-of-Way [Assignment]—the permitting
of vehicles and/or pedestrians to proceed in a lawful manner in preference
to other vehicles or pedestrians by the display of sign or signal indications.
- Road—see Roadway.
- Roadway—that portion of a highway improved,
designed, or ordinarily used for vehicular travel and parking lanes,
but exclusive of the sidewalk, berm, or shoulder even though such sidewalk,
berm, or shoulder is used by persons riding bicycles or other human-powered
vehicles. In the event a highway includes two or more separate roadways,
the term roadway as used herein shall refer to any such roadway separately,
but not to all such roadways collectively.
- Roadway Network—a geographical arrangement
of intersecting roadways.
- Road User—a vehicle operator, bicyclist,
or pedestrian within the highway, including workers in temporary traffic
control zones.
- Rumble Strip—a series of intermittent,
narrow, transverse areas of rough-textured, slightly raised, or depressed
road surface that is installed to alert road users to unusual traffic
conditions.
- Rural Highway—a type of roadway normally
characterized by lower volumes, higher speeds, fewer turning conflicts,
and less conflict with pedestrians.
- Shared Roadway—a roadway that is officially
designated and marked as a bicycle route, but which is open to motor
vehicle travel and upon which no bicycle lane is designated.
- Shared-Use Path—a bikeway physically
separated from motorized vehicular traffic by an open space or barrier
and either within the highway right-of-way or within an independent
alignment. Shared-use paths might also be used by pedestrians, skaters,
wheelchair users, joggers, and other nonmotorized users.
- Sidewalk—that portion of a street between
the curb line, or the lateral line of a roadway, and the adjacent property
line or on easements of private property, intended for use by pedestrians.
- Sign—any traffic control device that
is intended to communicate specific information to road users through
a word or symbol legend. Signs do not include traffic control signals,
pavement markings, delineators, or channelization devices.
- Sign Assembly—a group of signs, located
on the same support(s), that supplement one another in conveying information
to road users.
- Sign Illumination—either internal or
external lighting that shows similar color by day or night. Street,
highway, or strobe lighting shall not be considered as meeting this
definition.
- Sign Legend—all word messages, logos,
and symbol designs that are intended to convey specific meanings.
- Sign Panel—a separate panel or piece
of material containing a word or symbol legend that is affixed to the
face of a sign.
- Speed—speed is defined based on the
following classifications:
- Advisory Speed—a recommended speed
for all vehicles operating on a section of highway and based on
the highway design, operating characteristics, and conditions
- Average Speed—the summation of
the instantaneous or spot-measured speeds at a specific location
of vehicles divided by the number of vehicles observed.
- Design Speed—a selected speed used
to determine the various geometric design features of a roadway.
- 85th-Percentile Speed—The speed
at or below which 85 percent of the motorized vehicles travel.
- Operating Speed—a speed at which
a typical vehicle or the overall traffic operates. Operating speed
may be defined with speed values such as the average, pace, or 85th-percentile
speeds.
- Pace Speed—the highest speed within
a specific range of speeds that represents more vehicles than in
any other like range of speed. The range of speeds typically used
is 10 km/h or 10 mph.
- Posted Speed—the speed limit determined
by law and shown on Speed Limit signs.
- Statutory Speed—a speed limit established
by legislative action that typically is applicable for highways
with specified design, functional, jurisdictional and/or location
characteristic and is not necessarily shown on Speed Limit signs.
- Speed Limit—the maximum (or minimum)
speed applicable to a section of highway as established by law.
- Speed Measurement Marking—a white transverse
pavement marking placed on the roadway to assist the enforcement of
speed regulations.
- Speed Zone—a section of highway with
a speed limit that is established by law but which may be different
from a legislatively specified statutory speed limit.
- Stop Line—a solid white pavement marking
line extending across approach lanes to indicate the point at which
a stop is intended or required to be made.
- Street—see Highway.
- Temporary Traffic Control Zone—an area
of a highway where road user conditions are changed because of a work
zone or incident by the use of temporary traffic control devices, flaggers,
police, or other authorized personnel.
- Traffic—pedestrians, bicyclists, ridden
or herded animals, vehicles, streetcars, and other conveyances either
singularly or together while using any highway for purposes of travel.
- Traffic Control Devices—all signs,
signals, markings, and other devices used to regulate, warn, or guide
traffic, placed on, over, or adjacent to a street, highway, pedestrian
facility, or bicycle path by authority of a public agency having jurisdiction.
- Traffic Control Signal (Traffic Signal)—any
highway traffic signal by which traffic is alternately directed to stop
and permitted to proceed.
- Train—one or more locomotives coupled,
with or without cars, that operates on rails or tracks and to which
all other traffic must yield the right-of-way by law at highway-rail
grade crossings.
- Transverse Markings—pavement markings
that are generally placed perpendicular and across the flow of traffic
such as shoulder markings, word and symbol markings, stop lines, crosswalk
lines, speed measurement markings, parking space markings, and others.
- Traveled Way—the portion of the roadway
for the movement of vehicles, exclusive of the shoulders, berms, sidewalks,
and parking lanes.
- Urban Street—a type of street normally
characterized by relatively low speeds, wide ranges of traffic volumes,
narrower lanes, frequent intersections and driveways, significant pedestrian
traffic, and more businesses and houses.
- Vehicle—every device in, upon, or by
which any person or property can be transported or drawn upon a highway,
except trains and light rail transit operating in exclusive or semiexclusive
alignments. Light rail transit operating in a mixed-use alignment, to
which other traffic is not required to yield the right-of-way by law,
is a vehicle.
- Warning Sign—a sign that gives notice
to road users of a situation that might not be readily apparent.
- Warrant—a warrant describes threshold
conditions to the engineer in evaluating the potential safety and operational
benefits of traffic control devices and is based upon average or normal
conditions. Warrants are not a substitute for engineering judgment.
The fact that a warrant for a particular traffic control device is met
is not conclusive justification for the installation of the device.
- Wrong-Way Arrows—slender, elongated,
white pavement marking arrows placed upstream from the ramp terminus
to indicate the correct direction of traffic flow. Wrong-way arrows
are intended primarily to warn wrong-way road users that they are going
in the wrong direction.
Section 1A.14 Abbreviations
Used on Traffic Control Devices
Standard:
When abbreviations are needed for traffic control devices, the abbreviations
shown in Table 1A-1 shall be used.
Guidance:
The abbreviations for the words listed in Table 1A-2 should not be used
in connection with traffic control devices unless the prompt word shown
in Table 1A-2 either precedes or follows the abbreviation.
Standard:
The abbreviations shown in Table 1A-3 shall not be used in connection
with traffic control device because of their potential to be misinterpreted
by road users.
Table 1A-1. Acceptable Abbreviations
| Word Message |
Standard Abbreviation |
| Afternoon / Evening |
PM |
| Alternate |
ALT |
| Avenue |
AVE |
| Bicycle |
BIKE |
| Boulevard |
BLVD |
| Cannot |
CANT |
| CB Radio |
CB |
| Center |
CNTR |
|
Civil Defense
|
CD |
| Compressed Natural Gas |
CNG |
| Crossing (other than highway-rail) |
XING |
| Diesel Fuel |
D |
| Do Not |
DONT |
| Drive |
DR |
| East |
E |
| Eastbound |
EB |
| Electric Vehicle |
EV |
| Emergency |
EMER |
| Entrance, Enter |
ENT |
| Expressway |
EXPWY |
| Feet |
FT |
| FM Radio |
FM |
| Freeway |
FRWY, FWY |
| Friday |
FRI |
| Hazardous Cargo |
HC |
| Hazardous Material |
HAZMAT |
| High Occupancy Vehicle |
HOV |
| Highway |
HWY |
| Highway-Rail Grade Crossing Pavement Marking |
RXR |
| Hospital |
H |
| Hour(s) |
HR |
| Information |
INFO |
| It Is |
ITS |
| Junction / Intersection |
JCT |
| Kilogram |
kg |
| Kilometer(s) |
KM |
| Kilometers Per Hour |
km/h |
| Lane |
LN |
| Left |
LFT |
| Liquid Propane Gas |
LP-GAS |
| Maintenance |
MAINT |
| Meter(s) |
M |
| Metric Ton |
t |
| Mile(s) |
MI |
| Miles Per Hour |
MPH or M.P.H. |
| Minute(s) |
MIN |
| Monday |
MON |
| Morning / Late Night |
AM |
| Normal |
NORM |
| North |
N |
| Northbound |
NB |
| Parking |
PKING |
| Pedestrian |
PED |
| Pounds |
LBS |
| Right |
RHT |
| Road |
RD |
| Saturday |
SAT |
| Service |
SERV |
| Shoulder |
SHLDR |
| Slippery |
SLIP |
| South |
S |
| Southbound |
SB |
| Speed |
SPD |
| Street |
ST |
| Sunday |
SUN |
| Telephone |
PHONE |
| Temporary |
TEMP |
| Thursday |
THURS |
| Tires With Lugs |
LUGS |
| Tons of Weight |
T |
| Traffic |
TRAF |
| Travelers |
TRAVLRS |
| Tuesday |
TUES |
| Two-Way Intersection |
2-WAY |
| Two-Wheeled Vehicles |
CYCLES |
| US Numbered Route |
US |
| Vehicles |
VEH |
| Warning |
WARN |
| Wednesday |
WED |
| West |
W |
| Westbound |
WB |
| Will Not |
WONT |
Table 1A-2. Abbreviations That Are Acceptable Only with a Prompt Word
| Word |
Abbreviation |
Prompt Word |
| Access |
ACCS |
Road |
| Ahead |
AHD |
Fog* |
| Blocked |
BLKD |
Lane* |
| Bridge |
BRDG |
[Name]* |
| Condition |
COND |
Traffic* |
| Congested |
CONG |
Traffic* |
| Construction |
CONST |
Ahead |
| Downtown |
DWNTN |
Traffic* |
| Eastbound |
E-BND |
Traffic |
| Exit |
EX, EXT |
Next* |
| Express |
EXP |
Lane |
| Frontage |
FRNTG |
Road |
| Hazardous |
HAZ |
Driving |
| Interstate |
I |
[Number] |
| Local |
LOC |
Traffic |
| Lower |
LWR |
Level |
| Major |
MAJ |
Accident |
| Minor |
MNR |
Accident |
| Northbound |
N-BND |
Traffic |
| Oversized |
OVRSZ |
Load |
| Prepare |
PREP |
To Stop |
| Pavement |
PVMT |
Wet* |
| Quality |
QLTY |
Air* |
| Roadwork |
RDWK |
Ahead [Distance] |
| Route |
RT |
Best* |
| Southbound |
S-BND |
Traffic |
| Township |
TWNSHP |
Limits |
| Turnpike |
TRNPK |
[Name]* |
| Upper |
UPR |
Level |
| Vehicle |
VEH |
Stalled* |
| Westbound |
W-BND |
Traffic |
| * These prompt words should precede the abbreviation |
Table 1A-3. Unacceptable Abbreviations
| Abbreviation |
Intended Word |
Common Misinterpretations |
| ACC |
Accident |
Access (Road) |
| CLRS |
Clears |
Colors |
| DLY |
Delay |
Daily |
| FDR |
Feeder |
Federal |
| L |
Left |
Lane (Merge) |
| LT |
Light (Traffic) |
Left |
| PARK |
Parking |
Park |
| POLL |
Pollution (Index) |
Poll |
| RED |
Reduce |
Red |
| STAD |
Stadium |
Standard |
| WRNG |
Warning |
Wrong |
|
