Overview
:
Evolution
of MUTCD
Who Uses MUTCD
The
Evolution of MUTCD
Information
for this article was developed from a series of articles by H. Gene
Hawkins, Jr. published in the ITE
Journal published between 1991 and 1994.
The arrival
of the automobile early in this century started a revolution in
travel — and traffic control devices have developed to keep 20th
century travelers moving ever more safely to their destinations.
Road signs were the first traffic control devices to direct travelers
on their journeys. The evolution of these road signs provides a
fascinating insight not only into the evolution of traffic control
devices, but also to the pace of economic and social development
in our Nation.
The Horseless
Carriage Arrives
It was a bit
like the old saying about being "all dressed up, and no place
to go." The early days of the automobile found intrepid "tourers"
out for a drive, only to wind up losing their way because directional
signs were either nonexistent or they were broken, unreadable, or
knocked down. In fact, as early as 1899, horseless carriage owners
in New York City met at the Waldorf-Astoria Hotel for the purpose
of forming an automobile club — the predecessor of the American
Automobile Association — and part of their function was to place
and maintain signs on principal local highways to guide drivers
through the area or to specific sites.
Records indicate
that in 1905, the Buffalo Automobile Club installed an extensive
signpost network in the New York State. In 1909, the Automobile
Club of California undertook the task of signing the principal highways
within a 250-mile radius of San Francisco. These could be actual
signs, or perhaps they were colored bands around a utility pole.
Similar clubs conducted comparable efforts in local areas around
the Nation. Unfortunately, competition for signing certain popular
routes was fierce and organizations became increasingly aggressive
as to which club would sign which routes. One study noted that for
40 to 50 percent of the more traveled roads, it was common to encounter
as many as 11 different signs for one single trail or route.
But First,
Some Other Firsts
While automobile
clubs were busy developing early road signs, other entities were
developing devices to control the flow of traffic. For example:
- 1911, a centerline
is painted on a Michigan road.
- 1914, the
first electric traffic signal is installed in Cleveland.
- 1915, the
first STOP sign appears in Detroit.
- 1916, the
Federal-Aid Act requires that a State have a highway department
before it can get Federal money.
- 1918, Wisconsin
is the first state to erect official route signs as part of its
maintenance functions.
- 1920, the
first 3-color traffic signal is installed in Detroit.
The First
Signs of the Times
In the early
1920s, representatives from Wisconsin, Minnesota, and Indiana toured
several States with the intent of developing a basis for uniform
signs and road markings. The group reported its findings to the
Mississippi Valley Association of Highway Departments (MVASHD) in
1932. Their efforts resulted in standards for sign shapes, some
of which are still in use as we enter the 21st century.
These pioneers
devised a plan to classify sign shapes according to the level of
danger represented by highway situations. For example, round signs
warned of approaching railroad crossings, which even then represented
the most potential danger to the driver. The octagon advised of
the next level of danger — the need to STOP for intersections. Diamond
signs indicated more ordinary conditions that required drivers to
be cautious. Rectangular signs provided direction or other regulatory
information. All signs were black letters on white background and
were limited to 2 feet (0.6 m) square — that was the maximum width
of sign-making equipment. Because round and octagon shapes required
the most cutting and wastage, they were chosen for the fewest installations.
These shapes made sense because there was little illumination of
signs and the rationale was that drivers would respond to the shape
of the sign even when they couldn’t see the letters.
In 1924, the
First National Conference on Street and Highway Safety (NCSHS) improved
on earlier efforts and proposed standardizing colors for traffic
control devices. Again, many remain in use today. For example, signs
with white letters on a red background indicated STOP. White letters
on a green background signified proceed. Black letters on a yellow
background advised caution. Black and white signs providing information
on direction and distance were specified for every intersection
and junction. One combination that didn’t last was white letters
on purple background, indicating an intersection!
The First
Signing Manual
Also in 1924,
the American Association of State Highway Officials (AASHO, the
forerunner of AASHTO) took earlier efforts one step further by issuing
a report that combined the previous efforts to standardize sign
shapes and colors. The report recognized the superior visibility
of the yellow background and advised its adoption for all danger
and caution signs, including the STOP sign. The use of red was rejected
because of its inadequate visibility at night. This report was also
the first to propose the shield to designate U.S. highways.
The importance
of the AASHO report is that it became the basis for the first guidebook,
Manual and Specifications for the Manufacture, Display, and Erection
of U.S. Standard Road Markers and Signs, in 1927. However, this
manual addressed only use and design for signs on rural roads. Following
a national survey of existing traffic control devices, the Manual
on Street Traffic Signs, Signals, and Markings was published
to address urban traffic control devices. This manual corresponded
with the AASHO rural manual, except that material also addressed
traffic signals, pavement markings, and safety zones. The manual
also allowed smaller signs in urban areas, and the STOP sign was
modified to allow red letters on a yellow background.
MUTCD, Vol.
1
It was immediately
apparent that having two different manuals simply confused the attempt
to standardize traffic control devices. Thus in 1932, AASHO and
NCSHS formed the first Joint Committee on Uniform Traffic Control
Devices (JC). In 1935, the first MUTCD was published. More accurately,
it was mimeographed. The demand for the manual was so great, that
a printed version was published in 1937. In comparison to the Millennium
Edition, the 1937 printed version was only166 pages; content
was separated into four parts that addressed signs, markings, signals,
and islands.
The 1935 edition
set the standard for types of signs by classifying them as regulatory,
warning, or guide signs. Regulatory signs were black on white rectangles
(except the STOP sign was black on yellow or yellow on a red octagon);
diamond-shaped slow-type signs warned drivers to slow down; signs
that cautioned were square. The manual also promoted using symbols
on signs because nighttime roadway illumination was becoming more
common.
The 1935 MUTCD
also defined some pavement markings. For example, centerlines were
required only on approaches to hill crests with a clear view of
less than 500 feet (152 m), short-radius curves, curves with restricted
view, or pavements wider than 40 feet (12 m). Acceptable colors
for centerlines were white, yellow, or black, depending on which
provided the greatest contrast. It also supplied much-needed clarification
on the number, color, and meaning of signal indications. The 3-color
signal was adopted as the standard for signal lenses.
In November
1935, the first edition of MUTCD was approved as an American Standard.
MUTCD Editions
Reflect Life in America
The 1935 MUTCD
established the need for a manual that standardized the use and
design of traffic control devices (TCDs). As the Nation grew and
changed, the MUTCD has grown and changed. The manual has been revised
approximately every decade to reflect that growth and change.
Early revisions
were just that — supplements to the existing edition. For example,
in 1939, the JC issued a 25-page supplement to the 1935 edition.
The supplement recommended changes for sign illumination, speed
signs, no-passing zone pavement markings, signal warrants, and pedestrian
signals. And, although illumination was recommended, white reflectors
(red for STOP signs) could be used to illuminate all signs.
The 1942, 208-page,
MUTCD described the types of traffic control devices to be used
during blackout conditions resulting from the war. Traffic control
standards were not lowered for blackout conditions, but rather special
blackout devices were to be used where necessary. For example, reflectorized
beads were required for use on all pavement markings required for
blackout conditions. Pavement markings were also used in lieu of
many signs that would normally be illuminated. This, by the way,
was the advent of using word messages in pavement markings.
As the end of
the war neared, traffic engineers realized that the MUTCD had to
be completely rewritten. Work on a peacetime edition began in 1944,
and a new volume was published in 1948. The major format change
in the postwar edition was reorganizing material so that every control
device was addressed in only one place. There was also a concerted
effort to simplify word signs, and a rounded-letter alphabet was
adopted as standard for all signs.
The 1954 15-page
supplement to the 1948 MUTCD included 47 revisions and a brief description
of each. The most significant change is that the color for the STOP
sign was white letters on red background, which resulted primarily
from the development of new fade-resistant finishes. The 1954 manual
also represents the shift from using mainly regulatory and warning
signs on interstate highways to including guide signs. This manual
also adopted the use of white letters on green background for Interstate
highways.
New MUTCD
Editions Signal America on the Move
Changes incorporated
into the 1961 MUTCD truly supplement reflected a changing America.
The text was 333 pages long and the manual had two new sections,
one to address construction and maintenance operations, which complemented
a major section addressing needs of the new Interstate Highway System.
There was also a section included for civil defense signing.
A completely
rewritten MUTCD premiered in 1971. Some of the most significant
changes included adding definition of "should," "shall,"
and "may" requirements. Orange was designated for construction
signing, yellow markings separated opposing traffic, and there was
a wider use of symbol signs. School signs were also adopted.
The 1978 MUTCD
contained two new parts that addressed highway-rail grade crossings
and traffic control for bicycle facilities. There were also revisions
addressing the fundamental safety principals concerning work zones,
the need for traffic control plans, and an upgraded section on barricades
and channelizing devices. New illustrations reinforced the signing
and pavement marking standards.
Revise, Update,
Amend
Succeeding publications of the MUTCD reflect the changing need of traffic control devices to accommodate increased traffic, higher speeds, more commercial traffic, and roads that serve travelers 24-hours a day in all types of weather. The speed with which technology, traffic control, and traffic operations change makes the MUTCD a dynamic and constantly changing document. This makes it difficult for those who depend on the MUTCD to remain current with new and changing standards and guidance. By publishing the MUTCD on the Internet, users have greater access to the most current information.
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