HomeMy Public PortalAboutChapter 6_Design_FINALW_1 Chapter 6
DESIGN
L.Y
This section outlines design standards and guidelines that are
recommended for use when constructing the Community Path. The Field
Projects team considered these standards when designing the Path and
determining where to site it. The goal of following these standards is to
help ensure that the Path is safe for pedestrians and bicyclists alike.
The following standards come from several local,regional and national
sources. Specifically, those for multi-use wpaths are from American
Association of State Highway and Transportation Officials' (AASHTO)
1999 Guide for the Development of Bicycle Facilities. The design standards for
cycle tracks are from Northeastern University Transportation Engineer
professor Peter Furth, the City of Portland Bureau of Transportation's
2010 report Bikeway Facility Design:Survey of Best Practices, and Alta
Planning and Design's 2009 report Cycle Tracks:Lessons Learned.
Multi-Use Path Widths
The recommended width for a two-way,paved multi-use path—also
called a shared use path—is 10 feet.' The width can be reduced to 8 feet
under some circumstances,particularly when bicycle and pedestrian use is
expected to be low and grades are relatively flat.When use is expected to
be high or grades are steep,paths may be as wide as 12 to 14 feet.
Multi-Use Path Grades
Multi-use paths should have grades of no more than 5 percent.'
Grades can be steeper for short sections when necessary, though it is
recommended that paths be widened by 4 to 6 feet where grades are
steep. AASHTO's Design for the Development of Bicycle Facilities provides the
guide for grade restrictions and lengths:
is
59 Watertown Community Path
Grade Restriction Lengths
5-6% for up to 800 ft
7% for up to 400 ft
8% for up to 300 ft
9% for up to 200 ft
10% for up to 100 ft
11+% for up to 50 ft
Most of the Watertown Community Path is expected to run along a
relatively flat corridor, though there is a gentle slope on Arsenal Street
toward Watertown Square. There is at least one area—the section
around the Patton Street bridge—that may require a steep grade. If the
properties on either side of the bridge are made into graded slopes or
hills to accommodate the Path, the grade would be about 5.5 percent (for
up to about 200 feet on either side).
Cycle Track Separation Devices and Widths
Cycle tracks are bicycle paths that are separated from pedestrian and
vehicular traffic by a physical barrier, such as on-street parking, curbs,
planting buffers, or bollards. They can also be grade-separated from
roadways and sidewalks. The photos in Figures 6.1 and 6.2 show different
types of barriers or separation devices.
Figure 6.1 Figure 6.2
Uasser Street Cycletrack in Cambridge,MA; Kent Street Cycletrack in New York City;
Source:Kris Carter Source:Seth Holladay
i
- I
Design 60
Cycle tracks are best suited for arterial roadways with higher motor
vehicle speeds and volumes and roads with longer blocks and fewer
cross-streets.'To show that cycle tracks are intended for bicyclists,
pavement markings or different textures or colors should be used.'
A two-way cycle track should be at least 7.5 feet wide,with about 3.75
feet for each "lane."'Wider is typically better, though recommended
widths tend to vary depending on the bicyclist traffic volumes.
Centerlines
A 4-inch painted centerline is recommended for cycle tracks that are
more than 6.5 feet wide.6 Similarly, a 4-inch yellow centerline is suggested
for multi-use paths to separate opposite directions of travel.'
Cycle Track Intersections
At intersections with driveways and low-volume cross streets, bicyclists in
a cycle track should have the right-of-way.'At these crossings, the cycle
track could have markings or a different coloration or texture to indicate
that motor vehicles entering or exiting the driveways and cross streets are
expected to yield. The grade of the cycle track should remain the same
throughout the crossings. This applies to cycle tracks that are already
at a higher grade than the roadway; the cycle tracks become "raised
sidewalks" at the crossings.'The photo below shows an example of this.
At signalized intersections—like the one at Irving and Arsenal streets—
several treatments or techniques can be used to improve safety conditions
for bicyclists. The following examples are from Alta Planning and Design
as well as Dr. Furth's cycle track presentation.10
Figure 6.3
Raised crosswalks provide safer crossings
Source: WYlashingtonpost.com
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61 Watertown Community Path
Move the stop line for motor vehicles about 16 feet back,
while allowing cyclists to wait closer to the intersection;
Drop into a bicycle lane about 16 feet from the intersection;
Remove parking within 16 feet of the intersection;
Paint the cycle track or put down bike markings through the
intersection;
Only allow motor vehicles to turn left across a cycle track on
a green arrow (protected left);
> Use a leading"thru" arrow,which allows bikes to cross the
intersection before allowing motor vehicles to turn left across
a cycle track;
> Use separate signal phases for motorists from signal phases
for bicyclists, and use a bicycle signal head;
Install a pedestrian/bicyclist-actuated signal button.
Multi-Use Path Intersections
There are several improvements that can be made to intersections where
a multi-use path crosses through an existing intersection like the one at
Irving and Mount Auburn streets. AASHTO's Design for the Development of
Bicg&Facilities provides several suggestions,including the installation of a
signal." This could include a bicyclist/pedestrian-actuated signal button,
which should be placed about 4 feet high. Another option,particularly
for roads with high volumes of traffic,is to provide a refuge island to
make a two-step crossing for path users. In addition, crossing distances
can be shortened by using bump-outs.
Pavement markings should also be used at the crossing to clearly indicate
to motorists the presence of the Path. Other options include raised
crosswalks and colorized pavement crosswalks.
Sidewalks and Curbs
An ordinance adopted by the Watertown Town Council in February 2010
sets out standards and requirements for curbs and sidewalks in town. It
also outlines adequate widths for travel and parking lanes for different
roadway classifications.12
Travel lane width: 11 feet on principal arterials (Arsenal,
Main,Mount Auburn and Pleasant streets) and minor
arterials, and 10 feet for collectors and local roads; and
Parking lane width:7 feet in residential areas and 8 feet in
commercial areas.
Design 62
Under the ordinance, sidewalks are to have a"preferred clear walking
surface of 5 feet, not including curbing with a minimum of 4 feet."13
They are to conform to the Americans with Disabilities Act and
Massachusetts Architectural Access Board guidelines unless exempted by
Watertown's Superintendent of Public Works. In addition, at least 3 feet
of clearance must be provided around obstructions like utility poles.
6.2 Cross Sections
Figure 6.4 depict cross sections for Arsenal Street between School Street
and Irving Street. They show existing conditions on Arsenal Street
between School and Louise streets (with bike lanes) and Arsenal Stret east
of Louise Street (no bike lanes). Also shown is the recommended cross
section,which includes a cycle track and extended sidewalk.
Figure 6.4 Efisti_ng conditions with hike]one from School Street to Louise Street
Cross sections along Arsenal Street 52 Feat Wide
Source:Eunice Kim
SldewsiM Psndn Trawl Travel Pe 5&-walk
9 �9
5ke1 8 I 14f 14f*M 0feet :5
Ulke Nine aike I$no
4 feel 4 feel
Existing conditions with no bike lane west of Loulse Street
52 Feat Wide
I I " �=
5 d,Bwelk Partcing Travel Travel Perky SKk relk
5 feet 10 feet 16 feet 16" 10f t 5 feO
Preferred opifon between Louise Str"r and Irving Street
52 FeetWide
SIdevialk Buhr TrQvo Travel Perking Skle%alk
R felkl I a rv+ri I 11 furl 11 flit 11 feet 5 F"
2-way cycle(rack Periiinq
a feet a Feet
63 Watertown Community Path
Figure 6.5 shows recommended cross sections for the existing Linear
Park path and the municipal parking lots. In both areas,the team
recommends that the proposed Community Path be 10 feet wide. The
width of the vegetation will differ.
Proposal conditions For[_fnar Park pith Figure 6.5
Cross sections for multi-use paths
Source:Michelle Moon
L L•
Community Path Buffer
2-way 2 tr}15 feet
10 feet (M lh�0o
speoe eveilehla�
Community Pack—Preferrrd Option for Parking Lots
l'
Community Path Buffer
2-way (Wkith depends on
10 fedt WrI9 J"118M)
6.3 Conceptual Drawings
The Field Projects team developed conceptual drawings to help illustrate
what different sections of the Community Path could look like. The
drawings consist of three scenarios: a cycle track along Arsenal Street, a
shared use path through the municipal parking lot behind the library in
Watertown Square, and the existing Linear Park path.
Design 64
Cycle Track
The Field Projects team has recommended that a cycle track be
constructed on Arsenal Street from School Street to Irving Street as part
of the preferred route discussed in Section A.1 of Chapter 5.A cycle
track is also recommended as an alternative route between Irving and
Taylor streets. Figures 6.6 and 6.7 show a conceptual design of a cycle
Figure 6.6 track on Arsenal Street.
View of an 8 foot-mide cycle track on
Arsenal Street with a 2 foot-wide curb to act
as a buffer from the parked cars;
Source: Michelle Moon
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Figure 6.7
Plan view of cycle track along Arsenal
Street;
Source: Michelle Moon
65 Watertown Community Path
Municipal Parking Lot
Figures 6.8. and 6.9 show conceptual designs for the Community Path
through the municipal parking lot behind the Watertown Free Public
Library. That portion of the Path is explained in Section BA of Chapter
5. The conceptual designs include wide vegetative buffers, raised
crosswalks, benches and additional lighting. There may only be a few
opportunities to realize this ideal scenario,but modifications can be made
where space is limited. For example, the width of the vegetative buffers Figure 6.8
can be reduced.
View of the Path passing through municipal
parking lots in ilatertown Square;
Source:Michlle Moon
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Figure 6.9
Plan view of the Path in the municipal
parking lots;
Source.Michelle Moon
s
Design 66
Shared Use Path
Figures 6.10 and 6.11 show conceptual designs of the existing Linear
Park path,which is discussed in Section B.2 of Chapter 5. The designs
include improvements to the existing path.
Figure 6.10
Plan view of Linear Park path entrance
Source:Michelle Moon
Figure 6.11
Linear Park path entrance
Source.'Michelle Moon
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67 Watertown Community Path
6.4 Amenities
There are a number of amenities that would help make the Community
Path safer and more attractive. They could also be used to improve the
existing Linear Park path. Many of the amenities,which are listed below,
are depicted in the conceptual designs and are merely suggestions.
Convenience Amenities Navigation
Benches > Bicycle and pedestrian
Garbage cans signs
Bike racks > Pavement markings
Picnic tables > Directional signage
Drinking water > Intersection signage
fountains for Path users
Educational signage
Doggy bag stations Safety
Bollards
Other Amenities > Gates
Landscaping > Lights
Signs with emergency
Bird box call numbers
Community art > Emergency phones
Storage facilities Figure 6.12
Seating and brickwork along the Somerville
Community Path;
Source:Michelle Moon
i
Design 68
Recommended Plants
There are many horticultural opportunities along the Path corridor.
Because shared use paths and bike paths are linear, they have the
tendency to only include a few species of plants. However, to make the
Path more visually interesting,it is important to use a variety of plants.
This would also increase the biodiversity in Watertown and create four
seasons of interest. Perennials and annuals would provide color during
the summer months,while magnolia trees, tulips and daffodils would
provide color in the spring. Figures 6.13 and 6.14 show an example of
Figure 6.13 Example of diverse plantings; this plant variety. A list of plants is also provided in Appendix D.
Source:Michelle Moon
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Figure 6.14
Colorfulperennialgarden;
Source:Michelle Moon
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69 Watertown Community Path
Additional Design Elements
This section provides several ideas about how to design the
Community Path and its corridor in a more interesting, bio-diverse and
environmentally-friendly way. The following elements are suggestions.
> Rain Gardens: The municipal parking lot scenario in Chapter
6.3 offers environmental opportunities to address the
issue of stormwater run-off through low impact design.
The impervious surfaces of parking lots do not allow
for stormwater run-off to infiltrate into the soil,instead
directing the water to the sewer system. Installing rain
gardens alongside the Community Path would allow for this
stormwater to infiltrate the soil, thus alleviating pressure on
the sewer system and providing natural irrigation.
> Edible Plants: There are opportunities to plant edible plants
like blueberries and apple trees along the Path corridor in
Sections B.2 and B.3. It is important to purchase grafted trees
to ensure they are small and to help reduce the time it takes
for a tree to start producing edible fruit. Educational signs
should also be installed alongside the plants to inform Path
users about the specific plants and which ones are safe to eat.
> Habitat Areas: Vegetation along the Path will help provide
habitat for animals. For community or school projects,bird
houses and feeders could be installed along the Path to help
attract a greater diversity of wildlife.
> Educational and Directional Signage: Signs are an important
element to direct and educate users and to help visually unify
the Path. Maps depicting distances and places of interest Figure 6.15
would also help users navigate the Path. Educational signs Example of a raingarden;
could include information about historic Watertown. Source:Pararie Restorations Inc.
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Design 70
Educational and Community Opportunities
There are many opportunities for the Town to partner with other
organizations or public schools. Local garden clubs and community
groups could help create the text for the signs or information kiosks
along the Path. This would be a way to help engage local youth and help
reduce Path-related costs. School groups of all ages could be invited
to learn about horticulture and environmental science along the Path.
Students could help with the maintenance of the Community Path during
the summer. This would help meet several goals,including continued
engagement of the community and proper maintenance of the Path.
The concrete wall that separates the Linear Park path from the Whitney
Towers could be used for a community art project,which would result in
a permanent mural. Various issues would need to be addressed,including
artist choice and payment, necessary approvals, community involvement,
long-term maintenance plans and support from abutters. Some
community groups,including the Watertown Middle School Community
Mural Club,have already expressed an interest in seeing this mural
become a reality. This wall is approximately 210 feet long, 7 feet high and
1,470 square feet in size.
Endnotes
1 American Association of State Highway and Transportation Officials. "Guide for the
Development of Bicycle Facilities." http://safety.fhwa.dot.gov/ped—bike/docs/b—
aashtobik.pdf.
2 Ibid, page 39.
3 City of Portland Bureau of Transportation. "Bikeway Facility Design:Survey of
Best Practices." http://www.portlandonline.com/transportation/index.
cfm?c=44674&a=266116.
4 Alta Planning and Design."Cycle Tracks: Lessons Learned." http://www.altaplanning.
com/App—Content/files/pres_stud_docs/Cycle%20Track%201essons%201ea rned.pdf.
5 Peter Furth."Cycle Tracks:Concepts and Design Practices; Part 1:General Design,
Intersection Safety Treatments and Safety Studies." http://www.apbp.org/resource/
resmgr/webi na rs/ada_tp_3-17-10_fu 11_sl ide_se.pdf.
6 Alta Planning and Design."Cycle Tracks: Lessons Learned." page 12.
7 American Association of State Highway and Transportation Officials. "Guide for the
Development of Bicycle Facilities."
8 Alta Planning and Design."Cycle Tracks: Lessons Learned." page 6.
9 Peter Furth."Cycle Tracks:Concepts and Design Practices; Part 1:General Design,
Intersection Safety Treatments and Safety Studies."
10 Peter Furth."Cycle Tracks:Concepts and Design Practices; Part 1:General Design,
Intersection Safety Treatments and Safety Studies;"American Association of State
Highway and Transportation Officials. "Guide for the Development of Bicycle Facilities."
page 7-9.
11 American Association of State Highway and Transportation Officials."Guide for the
Development of Bicycle Facilities."page 49.
12 Watertown Town Council. "An Ordinance Governing the General Standards and
Requirements for Curbs and Sidewalks."
13 Ibid.
71 Watertown Community Path
Design •