B. 2011 Street Improvement Project: Options for Timberwood Emergency Connection to Stone Creek0
CITY OF
CHANHASSEN
7700 Market Boulevard
PO Box 147
Chanhassen, MN 55317
MEMORANDUM
TO: Paul Oehme, Director of Public Works /City Engineer
FROM: Alyson Fauske, Assistant City Engineer
DATE: February 14, 2011
y
Administration
SUBJECT: 2011 Street Improvement Project No. 11 -01: Options for the
Phone, 952.227.1100
Fax: 952.227.1110
Timberwood Drive "Emergency Only" Connection to Stone Creek
Court
Building Inspections
Phone: 952.227.1180
Fax: 952.227.1190
BACKGROUND
Engineering
Staff held a neighborhood open house on December 8, 2010.
Phone: 952.227.1160
Fax: 952.227.1170
Staff held a neighborhood meeting on January 12, 2011 to discuss the proposed
Timberwood Drive /Stone Creek Court street connection.
Finance
Phone: 952.227.1140
The public hearing was held on January 24, 2011.
Fax: 952.227.1110
Park & Recreation
DISCUSSION
Phone: 952.227.1120
Residents of the Timberwood area and Stone Creek Court attended the
Fax: 952.227.1110
neighborhood meeting on January 12, 2011 and the January 24, 2011 public
Recreation Center
hearing to voice their opposition to a public street connection between
2310 Coulter Boulevard
Timberwood Drive and Stone Creek.
Phone: 952.227.1400
Fax: 952.227.1404
At the public hearing the Council directed Staff to look into options for an access
between the two streets that would be for emergency purposes only. Staff has
Planning &
drafted three connection options for the Council's consideration, which are
Natural Resources
outlined below.
Phone: 952.227.1130
Fax: 952.227.1110
Public Works
1591 Park Road
Phone: 952.227.1300
Fax: 952.227.1310
Senior Center
Phone: 952.227.1125
Fax: 952.227.1110
Web Site
wwad.chanhassennn.us
Chanhassen is a Community for Life - Providing for Today and Planning for Tomorrow
City Project 11 -01: Timberwood/Stone Creek Connection
February 14, 2011
Page 2
OPTION #1: "Hammerhead" Turnaround at Stone Creek Court
This option provides a turnaround at the
end of Stone Creek Court so that vehicles
can make a three point turn to exit the
street rather than backing out or using a
private driveway to turn around.
The east -west portion of the turnaround is
proposed to be 20 feet wide and
approximately 60 feet long. The City's
typical turnaround is 100 feet long; in
order to fit the turnaround within the
existing right of way, the turnaround is
approximately 60 feet long. This
turnaround will be adequate for most
passenger vehicles; however larger
vehicles will still have difficulty turning
around. Plow trucks should be able to use
the turnaround and not have to back up all
the way to Stone Creek Drive as they
need to do today. One row of 9 button
delineators or barricades would be needed
instead of having two as there currently is
today.
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BARRICADES
8' BIT. TRAIL - ` - - ENGINEERED TURF
- - - - - CULVERT
RELOCATE
HYDRANT
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A 20 -foot wide, 10 -foot long patch of engineered turf would be installed between the existing cul
de sac on Timberwood Drive and the hammerhead on Stone Creek Court.
Engineered turf provides a vegetated strip between the two pavement surfaces, but is a structural
fill that can accommodate large vehicle loads on occasion.
The turf area would be minimally maintained by City crews. Illustrations of the turf are shown
below. Staff is still evaluating several manufactured products but in general most products have
the same basic design.
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City Project 11 -01: Timberwood/Stone Creek Connection
February 14, 2011
Page 3
DROGROW MIX BELOW RING
;UPPUED FREE BY MANUFACTURER
RINGS FILLED WITH CONCRETE SAND (CLEAN, SHARP SAND)
_ COMPACTED SANDY GRAVEL ROAD BASE
95'%MODIFIED PROCTOR DENSITY
- 6 tNCFIES TO 12 INCHES
(DEPTH OF BASE COARSE TO BE DETERMINED
BY ON- SITE ENGINEER)
_ COMPACTED SUBORADE,
Cross section of the engineered turf.
This option requires the installation of a culvert under the hammerhead section to maintain the
existing drainage pattern.
The trail connection would be realigned to extend from the Timberwood Drive cul de sac to the
west side of the hammerhead.
The existing hydrant at the end of Stone Creek Court would be relocated adjacent to the street
section within the right of way.
The estimated cost for Option #1 is $22,364, assuming City crews would relocate the hydrant.
The cost of this option is higher than originally anticipated due to the extra pavement for the turn
around, fill and storm sewer pipe required to build the hammerhead turnaround. If City installs
the storm sewer the cost estimate would be $5,700 less.
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City Project 11 -01: Timberwood/Stone Creek Connection
February 14, 2011
Page 4
OPTION #2: Engineered Turf Connection Between the Existing Streets
For this proposal, the engineered turf
described in Option #1 would extend from
the edge of the existing pavement on both
Timberwood Drive and Stone Creek
Court.
This option does not provide northbound
vehicles on Stone Creek Drive a
turnaround option, which is the same as
the current condition.
The engineered turf would be a 25 -foot
wide, 45 -foot long vegetated strip that
would be minimally maintained by City
crews.
The trail would be realigned to extend
from the Timberwood Drive cul de sac to
the existing east -west trail section.
A culvert would be installed under the
realigned trail and the vegetated strip in
order to maintain the current drainage
pattern.
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BARRICADES
S' BIT. TRAIL I ENGINEERED TURF
- - CULVERT
BARRICADES__ _
RELOCATE
-.. -.- _ .HYDRANT
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The existing hydrant at the end of Stone Creek Court would be relocated adjacent to the street
section within the right of way.
The estimated cost for Option #2 is $25,000. If City crews relocate the hydrant and install the
storm sewer, the estimated cost would be $17,100, a savings of $7,900.
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City Project 11 -01: Timberwood/Stone Creek Connection
February 14, 2011
Page 5
OPTION #3: A Paved Connection Between the Existin2 Streets
This option provides a paved connection
with a standard vertical transition
between the two existing streets.
In order to provide a smooth transition
between these two streets approximately
250 feet of existing pavement would have
to be removed and replaced.
The existing trail would terminate at the
street.
A culvert would be installed under the
street connection in order to maintain the
current drainage pattern.
The existing hydrant at the end of Stone
Creek Court would be relocated adjacent
to the street section within the right of
way.
- - - - - -�
~ APPROXIMATELY 250' OF
EXISTING PAVEMENT WOULD
t NEED TO BE ADJUSTED TO
Uf TRANSIDON BETWEEN
u7 DM8ERW00D AND STONE CREEK.
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I CONSTRUCTION
�I LIMITS
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BARRICADES
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— — CULVERT
_ + BARRICADES
RELOCATE
HYDRANT
CONSTR CTION
- sil LIMITS I
The estimated cost for Option #3 is
$65,000.
The detailed cost estimate for this option is higher than originally anticipated due to the length of
pavement removal and replacement required to provide a smooth transition between the two
existing streets. Additional costs include:
• Almost 1,000 cubic yards of fill,
• Removal and replacement of approximately 250 feet of pavement,
• Removal and replacement of approximately 200 feet of curb and gutter,
• The relocation of a street light,
• The relocation of an electrical transformer, and
• The partial removal and replacement of the three driveways within the construction
limits.
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City Project I 1 -01: Timberwood/Stone Creek Connection
February 14, 2011
Page 6
SIGNAGE
Each option will require barricades /signage that meet the Federal Highway Administration
(FHA) requirements. A reflective sign is required on each side of the emergency connection and
there must be at least four feet from the pavement to the bottom of the sign,
The two sign options are as follows:
9 Button Delineator
This sign is approximately 2' high and 2'
wide. The signs should be spaced at least
6' apart.
Type 3 Barricade
This barricade is at least 5' high and 8'
wide. This is the type of barricade that is
currently at the end of both streets.
The sign posts are proposed to be U channel steel with break -away post anchors.
U- channel breakaway post anchors
U- channel posts are attached to breakaway anchors
with a 15" adapter piece.
Includes: Model 19 V -Loc, wedge,
15" adapter and hardware
V -La <onuete model wRA
Suggested use: u- channel adapter
2 -3 Ibsift. U- channel post n9 -Vew1
Some residents have requested that decorative bollards be used instead of
signage. These bollards are typically three feet high and less than one foot
wide. The FHA signage requirements would require that a "9 Button
Delineator" be installed on top of each bollard. It is unknown at this time
how a delineator would be connected to the bollard. The bottom of the sign
would need to be about 1' above the top of the bollard. To furnish and install
these bollards would cost approximately $900 each. Depending on which
option is chosen, 5 to 9 would be needed. If the bollards are installed
additional maintenance costs would be incurred if they are damaged and need to be replaced.
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City Project 11 -01: Timberwood/Stone Creek Connection
February 14, 2011
Page 7
RECOMMENDATION
Staff recommends Option #1 for the following reasons:
• Allows for pedestrian vehicles to turn around on Stone Creek Court.
• Better snow storage.
• Requires only one barricade line vs. two which the other two options require.
• Should allow snowplow trucks to turn around in hammerhead.
Staff also recommends the 9 button delineator versus the Type 3 barricade.
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