HomeMy WebLinkAboutM-89-0571CITY OF MIAMI, FLORIOA
INTER -OFFICE MEMORANDUM
To Honorab I e Mayor and Members of DATE . APR - 4 i989 PILE
the City Commission
_
SUBJECT: Report on the Use Of
Rumble Strips
(Speed Strips)
rRom REFERENCES.
Cesar H. Odlo
ENCLOSURES: Report
City Manager
EL
RECOMMENDATION:
It Is respectfully recommended that raised rumble strips be
Installed on a trial basis on selected streets within the City of
Miami. It Is further recommended that the Traffic Section of
Metropolitan Dade County Public Works review and approve the
locations of the rumble strips prior to installation.
_
BACKGROUND:
At the March 3, 1989 regular Commission meeting, the Department
of Public Works was directed to prepare a report for presentation
to the City Commission on the application of rumple strip
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Installations on streets within the City of Miami. To this end,
the attached report has been prepared from various Dade- County
Department of Public Works documents, the institute of
-°
Transportation Engineers (ITE) publication entitled "Residential
Street Design and Traffic Control", 1989 and field observations
at various Intersections where rumble strips have been Installed.
A REPORT ON THE APPLICATION
OF RUMBLE STRIPS
Prepared by the Department of
Public Works, City of Miami, Florida
Rumble strips can be described as patterned sections of rough
pavement which are usually installed to alert drivers to the
presence of a dangerous condition. or a specific control• device.
While used primarily on major streets, they apparently have been
used as a speed reduction device in neighborhoods. In Dade
County two types of roadway rumble strips are being used to alert
motorists: recessed strips and raised strips. The difference
between these two devices is readily seen on the attached detail
drawings.
Field observations were made at various intersections to
determine if the rumble strips had any positive effect on slowing
vehicular traffic after contact with the device. The recessed or
grooved strips were observed first. Located in the south bound
lane of Old Cutler Road just east of Red Road (S.W. 57 Avenue),
the recessed rumble strips were found to have a minimal effect on
slowing vehicular traffic. One reason for this may be due in
part to the higher vehicular speed on "this roadway. The
connection between vehicular speed and the success of the device
is something that was observed with the raised rumble strip
installations Found later in this report.
The raised rumble strips were observed at the intersections of
S.I. 248 Street (Coconut Palm drive) and S.W. 97 Avenue and S.W.
268 Street (Moody drive) and S.W. 112 Avenue. At the first
intersection, where vehicular speeds were estimated between 25
and 35 mph, approximately 35% of the vehicles reduced speed after
contact With the first set of rumble strips. It should be noted
that -the strips were installed on S.W. 97 Avenue which is a two
lane roadway. Traffic was relatively light during the
observation period. At the'second intersection the rumble stripe
were located on S.W.- 112 Avenue just north of S.W. 268 Street.
B.W. 112 Avenue is a four lane roadway at this location and
traffic was heavy` during the observation period. Less than 5% of
the vehicles reduced speed after contact with the first set of
rumble strips where the speed was estimated to be between 45 and
55 mph.
It would appear from field observations that the raised rumble
strips are most effective in lower -speed areas and ..in areas with
relatively- low traffic volumes. (It should be noted, however,
that there are no specific reports, to the Department's
knowledge, that can confirm or refute these observations). 1
y
Examples of streets recently studied- which may fall into this
category are Loquat and Kumquat Avenues between S.W. 37 Avenue
and LeJeune Road and S.W. 28 Street between S.W. 22 and 27
Avenues. Although at best only one-third of the observed
vehicles reduced speed after traversing the rumble strips, it is
the Department's opinion that they could be installed on the
above streets on a trial basis only.
As is suggested by their name, rumble strips generate noise when
contact is made by vehicular traffic. Frequent passage of
vehicles over the strips can be a nuisance and negative reactions
by area residents to the noise levels generated by the strips can
be anticipated.. It should be noted that all of the observed
installations were located on rural roads or roads where adjacent
structures were substantially separated from the roadway. The
generation of noise by these devices should not be taken lightly.
Rumble strips were tried previously by the Dade County Public
Works Department at the intersection of Douglas Road and Ingraham
Highway and were later removed after complaints of excess noise
by area residents. If rumble strips are to be installed on a
City street, it is suggested that a majority of property owners
on that street concur with the application of the rumble strips
and that they are fully aware of the noise generated by the
device.
ROADWAY RUMBLE STRIPS
(RECESSED)
TYPICAL
I' VARIES
rT� E. P.
m I
LANE LINE
SET I SET 2
PLAN VIEW
NOTE: ROADWAY RUMBLE STRIPS SHALL BE INSTALLED
ADJACENT TO R2-IS I# R2-5C SIGNS WHERE
SPECIFIED AND SHALL BE CUT ACROSS ALL
LANES IN THE DIRECTION OF TRAVEL FACING
THESE SIGNS.
F SEE PAGE I THIS DETAIL
1/4" (TYP.'
4. -1 ;-k - H
CROSS SECTIONAL- VIEW
REVISED STANDARD ROAD DETAIL
METROPOLITAN APRDVED ,,,,_..�
DADE COUNTY ROADWAY
PUBLIWORKS RUMBLE RIPS
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