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9-1
Roadway
Streetscape
Design
Lesson 9
&
9-2
Identify a range of roadway and
streetscape design strategies
Describe how roadway and streetscape
design can support local and regional
land use objectives
Describe the transportation and other
benefits and impacts of these strategies
Learning Outcomes
9-3
Identify appropriate contexts for applying
these strategies
Discuss processes, roles, and
responsibilities for implementing these
strategies
Identify changes to agency policies, project
selection criteria, funding programs, etc.
that may be required to implement these
strategies
Learning Outcomes (continued)
9-4
9.1 “Great Streets” and Land Use
9.2 Network Design
9.3 Highway Design in Practice
9.4 Complete Streets
9.5 Traffic Calming
9.6 Access Management
Lesson 9:
Roadway Streetscape Design&
9-5
What Makes a Street “Great”?
9-6
What Gives a Street Character?
Memorable environment
Sense of history or community
Space for urban public life
Move people
safely and
efficiently
Support land
use function
and aesthetics
Source: Allan Jacobs, Great Streets
9-7
Main Street, Annapolis
Source: www.greatstreets.org
Source: Hisham Ibrahim /Getty Images
9-8
Safe & Comfortable for all Modes
Source: www.pedbikeimages.org/ Dan Burden
Boulder, CO
9-15
East-West Gateway COG Program
Goal is “to trigger economic and social
benefits by centering communities around
interesting, lively and attractive streets”.
Fund demonstration projects
Design tutorial and other online resources
9-16
Great Streets Design Tutorial
Organized by Place Type
or context
Explores the five principal
elements of streets:
• Street wall,
• Pedestrian realm,
• Overhead area,
• Vehicle realm
• Subsurface area
Design details provided
for each
9-17
Multi-Modal
Corridor and
Public Space
Design Guidelines
Indianapolis Regional
Center & Metropolitan
Planning Area
9-19
9.1 “Great Streets” and Land Use
9.2 Network Design
9.3 Highway Design in Practice
9.4 Complete Streets
9.5 Traffic Calming
9.6 Access Management
Lesson 9:
Roadway Streetscape Design&
9-20
“Great Streets” and Small Blocks
Source: Allan Jacobs, Great Streets
Venice - 1500
intersections /square mile
Downtown LA - 150
intersections /square mile
Irvine, CA - 15
intersections /square mile
9-21
Thoroughfare Spacing and Sizing
ITE Recommended Practice:
• Conventional suburban areas – major
thoroughfares at up to 1 mile (6 lanes)
• Minor thoroughfares at ¼ mile or less
• More dense grid for more dense
development or fewer maximum lanes
More frequent thoroughfare spacing
means fewer lanes are needed
9-22
Transit Networks
Every major thoroughfare should serve
transit and pedestrians, as well as
private and commercial vehicles
Transit networks focus on existing and
planned TODs
9-23
Pedestrian and Bicycle Networks
Pedestrian networks
• Dense urban core areas –
400‟ blocks max,
200-300‟ preferred
• Elsewhere –
600‟ max, <400‟ preferred
Bicycle networks
• Through routes or facilities <1/2 mile apart
• Direct connections to major trip generators (schools,
parks, retail areas)
Source: Institute of Transportation Engineers
Bethesda, MD
9-24
Street Connectivity
Traditional Grid
Typical Suburb
Source: Institute of Transportation Engineers
9-26
Regulating Connectivity
In 2009, Virginia became the first state to
severely limit cul-de-sacs from future
developments.
New rules require that all new subdivisions
attain a certain level of "connectivity," with
ample through streets connecting them to
other neighborhoods and nearby commercial
areas.
9-27
Connectivity Index = Number of Street Links
Number of Network Nodes
Strive for better than 1.4
All the stub streets on this new development will be extended, providing good connectivity.
How Do You Measure Connectivity?
9-28
9.1 “Great Streets” and Land Use
9.2 Network Design
9.3 Highway Design in Practice
9.4 Complete Streets
9.5 Traffic Calming
9.6 Access Management
Lesson 9:
Roadway Streetscape Design&
9-29
Traditional Highway Design Approach
Traffic Volume + Area Type (urban, rural) + Role in Network
Functional Classification
Design Speed + Design Vehicle
Alignment + Cross-Section + Intersection + Roadside
9-30
Freeway
Arterial
• Major
• Minor
Collector
Local
Functional Classifications
Urban & Rural Contexts
9-31
Some roads classified as
principal arterials carry
predominantly local traffic
and have many access
points
The design speed for the
arterial class can be too high
for an arterial serving as the
“Main Street” of a
community
As land uses change, so
should roadway design
Both of these roadways
are principal arterials
Problems with Functional Classification
9-32
Change in Functional Classification:
Westminster, MD
Case Study
9-33
State Highway Serving an Historic Downtown
Westminster, MD
9-34
Change In Functional Classification
With Completion of Bypass
East Main Street
State allowed
City to take
ownership
9-35
Westminster –First CSS Project in Maryland
9-36
The AASHTO Green Book
AASHTO, A Policy on Geometric Design
of Highways and Streets (“Green Book”)
“Bible” of geometric design
Basis for many States‟ standards
Actually provides significant design
flexibility
9-37
Flexibility in AASHTO Guidelines Minimum for Urban Arterials
Design speed – 30 mph in CBDs
Design vehicle – Single unit truck
Lane width – 10 ft. for light truck traffic and speeds up to 37 mph
Shoulder width – Desirable but not required
Corner radii – 10-15 ft. under constrained conditions
Curbs – Vertical curbs up to 37 mph
9-39
Examples of State Standards
Outside AASHTO Ranges
Connecticut Idaho Vermont
Design Speed
Design Year Volume
Travel Lane Width
Parking Lane Width
Intersection SD
Stopping SD
Horizontal Curvature
Maximum Grade
Level-of-Service
9-41
Chapter 6: Designing the Roadway
9-42
Matrix of Design Values - Community Arterial
9-43
Design Speed: speed used to determine design features of roadway
Roads are typically designed to accommodate speeds above the speed limit
Absent strong enforcement, drivers tend to drive as fast as they believe the road can safely accommodate, regardless of posted speed.
Result: existing road design policy encourages speeding
Design Speed
9-44
Solution: Desired Operating Speed
9-45
Tort Liability
Discretionary functions of government
involve a choice among valid alternatives
For the most part, highway design
decisions are treated as discretionary
Highway design decisions are generally
immune from tort claims
9-46
PennDOT‟s Design Liability
PennDOT can be liable for failing to
select the most appropriate safety
measure, and cannot defend by claiming
its discretion as a defense
There is no discretionary immunity
Starr v. Veneziano
Source: Steve Roth, Esq.
9-47
PennDOT‟s Design Liability
Adherence to the
Green Book does
not automatically
establish
reasonable care
Deviation from the
Green Book does
not automatically
establish
negligence
Source: Steve Roth, Esq.
9-48
Actions to
Reduce Liability Exposure
Document non-typical design features
Use permissive language rather than mandatory
language
Statute/policy statement authorizing highway
designers to consider non-traditional factors on all
roads
Keep safety paramount
9-51
60’ to lot lines
40’ curb-curb
How would you allocate the space between
buildings for a typical cross-section?
What other design treatments would you
include?
Exercise:
Design Historic Main Street
9-52
An illustrative
concept plan
provides a
guide for the
appropriate
building
placement,
parking
arrangement,
buffer
placement and
street design.
Bedford Avenue Urban Design Overlay
Source: Metropolitan Government of Nashville and Davidson County
9-53
Design speed
Design vehicle
Lane width
Shoulder width
Corner radii
Curbs
Sidewalks
Clearance to street
trees
Pedestrian crossings
On-street parking
Textured surfacing
Refuge islands
Curb
extensions/bulbouts
Design Considerations
for the „Ideal‟ Main Street
9-54
9.1 “Great Streets” and Land Use
9.2 Network Design
9.3 Highway Design in Practice
9.4 Complete Streets
9.5 Traffic Calming
9.6 Access Management
Lesson 9:
Roadway Streetscape Design&
9-55
A street designed and
operated to enable safe,
attractive and
comfortable access and
travel for all users
What is a „Complete Street‟?
Source: www.pedbikeimages.org
9-56
Smart Corridors require complete streets
• A corridor that balances demands for
mobility, economic viability, environmental
quality and livability
• A corridor that integrates land use and
transportation dynamics
• A corridor that provides transportation
choices, that recognize the range of social
and economic groups and their needs
Relationship to Smart Corridors
9-57
Relationship to Smart Corridors
Source: City of Charlotte
9-59
Component Zones
Zone Min. Width
Curb Zone 6”
Planter/Furniture/
Utility Zone 24”, 48” if planted
Pedestrian Access Route 60”
Frontage Zone 30”
Total Sidewalk Corridor 10’-12’
Zone system divides the sidewalk corridor into
four zones to ensure that pedestrians have
sufficient clear space for walking
Source: Delaware Department of Transportation
9-60
Historically, cars did
not dominate city
streets
Traditional Complete Street
9-61
Seven Lanes, yet not „Complete‟
Spartanburg, SC
Source: Michael Ronkin
9-63
Benefits of Complete Streets
Improve safety for all road users
Increase capacity of transportation network
Improve transit
Fight climate change
Improve mobility for elderly, disabled and children
Encourage healthy and active lifestyles
Spark economic revitalization
9-64
State
• State of Connecticut: Senate Bill 735
• State of California: California Complete
Streets Act of 2008
• State of New Jersey: Complete Streets Policy
Local
• DuPage County, Illinois: “Healthy Streets
Initiative”
• Philadelphia, Pennsylvania: “Complete Streets
Executive Order”
State and Local Initiatives
9-65
Complete Streets Act of 2009 (introduced
in March 2009)
To ensure that all users of the transportation
system, including pedestrians, bicyclists,
transit users, children, older individuals, and
individuals with disabilities, are able to travel
safely and conveniently on and across
federally funded streets and highways.
(Source: www.completestreets.org)
Legislation for Complete Streets
9-66
Elements of a Complete Street
So
urc
e: P
roje
ct fo
r P
ub
lic S
pa
ce
s
9-67
Elements of a Complete Street
Sidewalks Crosswalks Refuge medians Parking
So
urc
e: P
roje
ct fo
r P
ub
lic S
pa
ce
s
Bus lanes Landscaping Lighting
9-68
Complete StreetsA How-to-Guide
9-69
Three-Step ApproachA
Ho
w -
to -
Gu
ide
1. Consider the context
2. Design the space
3. Implement the changes
Lewes, DE
9-71
Engage the CommunityA
Ho
w -
to -
Gu
ide
Tailor solutions to the context
Plan for all transportation modes
Understand valued resources before starting engineering design
Scale the solutions to the problem
9-72
Highway design is too
important to be left to
Highway Engineers.Tom Larson
Former PennDOT Secretary & FHWA Administrator
Co
ns
ide
r the
Co
nte
xtWhy Involve the Community?
9-73
Find the clues to the future in:
Municipal comprehensive plans
Redevelopment plans and economic
development plans
Availability of infrastructure
Visioning workshops/ design charrettes
Discussions with municipal officials and
the public
What is Community‟s Vision?C
on
sid
er th
e C
on
text
9-74
Consider Land Use
Source: www.farm3.static.flickr.com
Co
ns
ide
r the
Co
nte
xt
This or this
Balance mobility and accessibility
Access to destinations
Connecting land uses
Support economic development/
revitalization
9-75
Consider User Needs
Include space for motorists, transit users,
bicyclists, wheelchair users and pedestrians
Co
ns
ide
r the
Co
nte
xt
9-76
2. Design the SpaceD
es
ign
the
Sp
ac
e
Source: www.pedbikeimages.org/Dan Burden
9-77
Goals for Allocating Space
Improve Mobility and Access for all Modes
Improve Safety
Improve Livability and Quality of Life
Support Economic and Community Goals
Source: NYCDOT
De
sig
n th
e S
pa
ce
9-78
Road Diet
Source: Parsons Brinckerhoff
Lane Reduction
De
sig
n th
e S
pa
ce
9-79
This 5-lane Main Street went from this ….
Source: Michael Ronkin
Pottstown, PA
De
sig
n th
e S
pa
ce
…. to a Complete Street
9-81
Reduce Lane Widths
Roadways with high truck volumes may
need 12‟ lanes
Consider 11‟ lanes for roads at 35 mph
and higher
Consider
10‟ lanes
for low-
speed
urban
roadways
Re
du
ce
Lan
e W
idth
s
9-82
1. Lane & Shoulder Width 2. Street Trees
3. Curve Radius 4. On-street Parking
Reduce Travel Speed
Source: Smart Transportation Guidebook
Re
du
ce
Sp
ee
ds
9-83
In urban contexts, choose smallest curb radius that can accommodate the design vehicle
Balance need to accommodate truck turning movements with benefit of shortercrosswalks
Tighten Corner Curb RadiiR
ed
uc
e S
pe
ed
s
Source: Main Street… When a Highway Runs
Through It. A Handbook for Oregon Communities
9-84
On-street parking is a desirable part of
the urban fabric
• Slows passing
cars
• Buffers
pedestrians
• Convenient
for shoppers
Consider 7‟ and 8‟ wide parallel parking
spaces
Provide On-Street ParkingR
ed
uc
e S
pe
ed
s
Source: spacingmontreal
9-85
Full-width (8-12‟) shoulders are
critical on higher speed roadways
In urban and suburban areas,
shoulders of 4-6‟ are useful for
retrofitting wide travel lanes for
bicyclist safety
Need to accommodate pedestrians
on roads without sidewalks
Shoulder the LoadEn
ha
nc
e S
afe
ty
Source: www.pedbikeimages.org/ Dan Burden
9-86
Economic
activity is
supported by
providing
means to
arrive by car,
transit, bicycle
or foot
Access by Multiple ModesD
es
ign
the
Sp
ac
e
9-87
Comfortable & accessible stop/station
Dedicated lanes vs mixed in right-of-way
Visibility of stop/station
Transit ConsiderationsD
es
ign
the
Sp
ac
e
9-88
Improve cross
town transit
service
Reduce vehicular
and pedestrian
congestion
Provide
convenient
connections to
major land uses
and transportation
facilities
NYC‟s Proposed 34th Street TransitwayD
es
ign
the
Sp
ac
e
9-89
Transit Design – Bus Stops
Source: www.pedbikeimages.org/ Dan Burden & Libby Thomas
Bus Bay
Bus Bulb-Out
De
sig
n th
e S
pa
ce
9-91
On street vs. off street
How to negotiate intersections
Conflicts with driveways and on street parking
Buffering the bike lane increases safety
Bicyclist ConsiderationsD
es
ign
the
Sp
ac
e
9-92
Contra-flow bike
lanes provide
for two-way
bicycle travel on
a one-way
street
Cycle tracks
provide a
separated path
within roadway
infrastructure
Physical Separation from Traffic
15th Street, Washington D.C.
De
sig
n th
e S
pa
ce
Ninth Avenue, NYC
9-93
The Bike BoxD
es
ign
the
Sp
ac
e
Source: www.bikeportland.org
9-94
Bicycle SignalsD
es
ign
the
Sp
ac
e
Source: www.bikeportland.org
9-95
Bicycle SignageD
es
ign
the
Sp
ac
e
Source: www.bikeportland.org
9-96
Continuous sidewalk, 5‟-8‟ width, free from
obstructions
Visible crosswalk treatments on major roads
Universal design (ADA)
• Audible
crossing
signals
• Accessible
ramps at
corners
• Detectable
warning
surface
Pedestrian Considerations
Source: www.pedbikeimages.org/Dan Burden
De
sig
n th
e S
pa
ce
9-97
Streetscape Design Techniques:Pedestrian Treatments
Pedestrians‟ needs not fully or consistently
considered
De
sig
n th
e S
pa
ce
9-99
Pedestrian Design Treatments
Crosswalks, signage and markings
Curb extensions and radius reductions
Raised medians
Source: www.pedbikeimages.org/Dan Burden
De
sig
n th
e S
pa
ce
9-100
NYC Herald Square
Before
After
Source: NYCDOT
De
sig
n th
e S
pa
ce
9-101
A Shifting Paradigm
Source: Columbia Daily Tribune
De
sig
n th
e S
pa
ce
9-102
Safer for
vehicles, since
all movements
are right-in/
right-out
Consider RoundaboutsD
es
ign
the
Sp
ac
e
Oregon
9-104
Compatible with Complete Streets
Centennial Circle,
Glens Falls, New
York
Roundabout
replaced five-legged
intersection with
failing level of
service
Roundabout and
streetscaping
intended to revitalize
business district
9-106
Continuous SidewalksAppropriately Scaled D
es
ign
the
Sp
ac
e
Source: www.pedbikeimages.org/Dan Burden
9-107
Appropriate Buffering from TrafficD
es
ign
the
Sp
ac
e
9-108
Physical medians
are best for
pedestrians on
multi-lane roads
Width ranges
from 4 to 18 ft.,
depending in part
whether it houses
a left turn lane
Medians
Source: NYCDOT
De
sig
n th
e S
pa
ce
9-110
Human-Scale BuildingsD
es
ign
the
Sp
ac
e
9-111
Infrastructure & Green Design
Ecologically sustainable infrastructure is low impact and incorporates best management practices to enhance environmental quality
Oth
er C
on
sid
era
tion
s
„Green‟ elements can support safety, mobility and visual quality in a Smart Corridor
9-112
Green Streets A street that uses natural processes to
manage stormwater runoff at the source
Oth
er C
on
sid
era
tion
s
9-113
Benefits of Green Streets
Reduces impervious
surface
Improves water
quality
Reduces urban
heating
Enhances pedestrian
safety
Beautifies
neighborhoods
Source: New York City Dept of Parks & Recreation
Before
After
Oth
er C
on
sid
era
tion
s
9-114
Reduce perceived width of street, and
help calm traffic
Provide buffer strips of 4 to 5 ft. between
sidewalk and road
Consider safety in clear zone
Street TreesN
urtu
re S
tree
t Life
9-115
Permeable Paving
Suitable for parking lanes, sidewalks and
alleys
Oth
er C
on
sid
era
tion
sPortland, OR
9-116
Infiltration Basins Structured „rain
gardens‟ that use plants and soils to filter, absorb and slow stormwater flows into area waterways
Oth
er C
on
sid
era
tion
s
Source: City of Portland Bureau of Environmental Services
9-118
Stormwater Curb Extensions
Incorporates a rain garden into which runoff
flows
Can be located in residential and commercial
areas
Oth
er C
on
sid
era
tion
s
9-120
3. Implement the ChangesIm
ple
me
nt th
e C
ha
ng
es
9-123
Potential Funding Sourcesfor Implementation
Federal and State transportation funds
Municipal budgets
Developer fees, contributions and built roads
Special assessment districts
Tax-increment finance (TIF) revenues
Parking fees
Joint development
Imp
lem
en
t the
Ch
an
ge
s
9-124
9.1 “Great Streets” and Land Use
9.2 Network Design
9.3 Highway Design in Practice
9.4 Complete Streets
9.5 Traffic Calming
9.6 Access Management
Lesson 9:
Roadway Streetscape Design&
9-125
Traffic Calming
Measures to reduce speeding and/or
cut-through traffic in the interest of
safety, livability, walkability and
bikeability
Usually applied on local streets,
including Main Streets
Intended to improve safety throughout
the corridor
9-126
Professional Acceptance
Institute of Transportation
Engineers (ITE) Practice
AASHTO Acknowledgment
...consider traffic calming
measures…to address
congestion, safety, and quality
of life issues [when a] project is
scheduled for a village/main
street, school zone, or other
subarea, and … would satisfy
identified…needs …
9-127
State Traffic Calming Initiatives
Delaware – Traffic Calming Design Manual
South Carolina – Typical (standard) designs
New York – Application matrix
Source: New York State Department of Transportation.
Implementing Design
9-128
Traffic Calming Measures
Volume control measures
• Diverters
• Median barriers
Speed control measures
• Vertical deflection
• Horizontal deflection
• Narrowing
9-130
Speed
humps
Speed
tables
Raised
cross-
walks
Raised
intersect-
ions
Vertical Speed Control Measures
9-131
Horizontal Speed Control Measures
Neighborhood circles
Lateral shifts
Chicanes
9-136
Safety Impacts of Traffic Calming
Source: Ewing
Average Annual Collisions
MeasureNumber of Sites Before After Change
Humps 54 2.8 2.4 -14%
Tables 51 1.5 0.8 -47%
Circles
Without SeattleWith Seattle
17130
5.92.2
4.20.6
-29%-71%
Roundabouts 11 9.3 5.9 -37%
All Measures
Without AdjustmentWith Adjustment
23547
2.21.8
1.11.2
-50%-33%
9-142
9.1 “Great Streets” and Land Use
9.2 Network Design
9.3 Highway Design in Practice
9.4 Complete Streets
9.5 Traffic Calming
9.6 Access Management
Lesson 9:
Roadway Streetscape Design&
9-143
Loss of Function as a Principal Arterial
9-144
Roadway Functional Hierarchy
Theory Practice
9-145
Benefits of Access Management
Crashes per Million Vehicle-Miles
Source: Colorado Dept. of Highways
Average Running Speed (mph)
9-146
Access Management Techniques
Optimal signal spacing
Driveway controls
Corner clearances
Installation of medians
Frontage roads
Backage roads
9-147
What Access Management
Measures are in Place?
9-149
Access Points Set Back from Intersection
9-150
Preserving Function & Capacitywith Parallel Collectors
9-151
Backage Road and Distance to Intersection
9-152
Access Management Can Be Promoted
Without Having Legal Authority
9-153
Local Implementation
Pennsylvania Department of
Transportation
Model Ordinances
9-154
Design Guidance
Report examines
driveway-related
terms & definitions,
basic geometric
controls, a summary
of access spacing
principles, and
detailed discussions
of various geometric
design elements.
9-158
How Do We Make More Streets “Great”?
Agency policies and design standards
Long-range plan priorities
Land use policies and regulations
Local mapping and capital improvements
Project selection and scoping
Cross-agency/cross-discipline collaboration
Broad-based stakeholder and public
involvement
9-159
NHI-133078Access Management Location &
Design
NHI-142045Pedestrian Facility Design
NHI-380089Designing for Pedestrian Safety (New!)
Additional NHI Training
9-160
Additional NTI Training
Accessible Pedestrian Signals
9-161
Describe how the following strategy could support land use objectives: Applying a reduced lane and shoulder width on an arterial road
What are the benefits of this strategy? Are there other impacts – perhaps negative?
What would be an appropriate context in which to implement this strategy?
In your community, who would be involved in implementing this strategy?
What changes to policies, standards, design processes, or funding programs might be required to implement this strategy?
Review
9-162