Item M1 BOARD OF COUNTY COMMISSIONERS
AGENDA ITEM SUMMARY
Meeting Date: November 18, 2014 Division: Public Works/Engineering
Bulk Item: Yes No X Department: _Engineering Services Department
Staff Contact Person/Phone#: Judy Clarke X4329
AGENDA ITEM WORDING: Discussion regarding revising Monroe County policies to allow for
installation of speed humps on county maintained roads and, if speed humps are to be considered,
direction to staff to develop a process for evaluating and approving installation.
ITEM BACKGROUND: Historically Monroe County has not allowed the installation of speed
bumps on county maintained roads. Wider, flatter speed humps are recognized as an acceptable traffic
calming measure in the Manual of Uniform Minimuin Standards for Design, Construction and
Maintenance for Street and Highways (Florida Greenbook). Residents have requested that Monroe
County permit installation of speed humps on neighborhood roads.
The back-up for this item contains information about speed humps, a brief overview of advantages and
disadvantages of speed humps and recommended actions to evaluate whether they should be installed.
Staff is seeking direction on whether to commence with developing a process to evaluate requests as
well as input into the recommended process.
PREVIOUS RELEVANT BOCC ACTION: None
CONTRACT/AGREEMENT CHANGES: Not Applicable
STAFF RECOMMENDATIONS:
TOTAL COST: n/a INDIRECT COST: BUDGETED: Yes No
DIFFERENTIAL OF LOCAL PREFERENCE:
COST TO COUNTY: $0 SOURCE OF FUNDS:
REVENUE PRODUCING: Yes No AMOUNT PER MONTH Year
APPROVED BY: County Atty OMB/Purchasing Risk Management
DOCUMENTATION: Included X Not Required
DISPOSITION: AGENDA ITEM#
Revised 7/09
Engineering Department
MEMORANDUM � _..
To: Monroe County Commissioners
From: Judy Clarke, Director of Engineering Services,;
Date: November 4, 2014
Re: Discussion to Consider Speed Humps on County Maintained Roads
This discussion is in response to a request from the Duck Key Security District to install speed
humps on county roads within Duck Key. Monroe County's policy has been that it does not
install speed bumps, which are steeper than humps, on county maintained roads; therefore, a
discussion as to whether speed humps should be considered on all county roads as requests are
received is warranted.
The Manual of'Uniform Minimum Standards for Design, Construction and Maintenance far
Streets and Highways (Florida"Greenbook") considers the steeper, more severe speed bump as
an inappropriate treatment but indicates that the wider, flatter speed hump can be an effective
traffic calming treatment when used appropriately. Speed humps are parabolic or sinusoidal
shaped, 3 to 4 inches high in the center and at least 12 to 14 ft. long. They are designed to be
comfortable at speeds of 15-20 MPH and when installed in series, can slow traffic to the
appropriate speed limit on local roads (25 MPH). The construction cost, which includes
construction of the hump, pavement markings and signage can range from $3,000 to $8,000 per
hump (average from literature).
Advantages of Speed Humps
• When evaluated and installed properly they have been shown to be effective at slowing
traffic on local roads;
• They are effective 24 hours a day (as opposed to periodic enforcement by law
enforcement);
r Speed humps are relatively low cost compared to alternate traffic calming treatments.
Disadvantages of Speed Humps
• Speed humps can slow down emergency response vehicles; a study performed using a
variety of vehicles showed delays ranging from 0—9 seconds per hump;
9 They can create discomfort for chronic pain sufferers;
November 4, 2014
• They create a tendency for drivers to swerve off the road to avoid the hump where there
are no curbs;
• Municipalities have received increased noise complaints due to frequent braking and
accelerating at speed hump locations.
The Greenbook stresses that traffic calming should be undertaken with a firm planning process
that includes public involvement by impacted residents, documentation of need through
appropriate studies and coordination with service providers such as emergency responders,
sanitation, transit providers and schools, if applicable. The traffic calming solution should be
designed in accordance with proper engineering criteria.
Listed below are some of the more important guidelines that should be considered if the County
wants to consider developing a procedure to evaluate various neighborhoods for speed humps:
• There should be a requirement that petitioners achieve a high percentage (some
municipalities set this at 70% of impacted residents) of positive response to the proposal
to install humps via written petition. The petition should include an explanation of both
advantages and disadvantages of speed humps so that people are aware.
• A traffic study should be performed to determine if speed humps are warranted. Typically
local governments set a requirement that the study must show that the 85% speed on the
road is at least 10 MPH over the posted limit for humps to be warranted. If the study does
not document an actual speeding problem installing humps will not result in an
appreciable difference in speeds.
• Location and number of humps should be determined through engineering design; proper
distance from intersections, signals, obstructions to sight distance must be observed.
• Determine who will bear the cost of the traffic study, installation and maintenance of
humps. Some municipalities require homeowners' associations to fund the installation
with Public Works providing future maintenance; others consider the cost in annual road
budgets.
• Consideration should be given to what criteria will be used to determine whether humps
will be removed when requests are received.
Staff is requesting direction from the BOCC on whether we should proceed with developing a
policy to evaluate speed hump installation on county roads and input on items noted above that
will become part of any procedure that may be developed.
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