The document discusses context-sensitive solutions (CSS) in transportation, focusing on planning, environmental analysis, and design to create transportation systems that meet community needs, enhance safety, and harmonize with the environment. It outlines a step-by-step project development process including determining context, identifying community issues, developing and evaluating design alternatives, and incorporating stakeholder input. Key tenets of CSS include flexibility in design, multimodal approaches, and creating attractive, functional public spaces that enhance the urban fabric.

1. Context Sensitive Solutions in Transportation
Classes 19-22 Planning, Environmental Analysis and Design
Using CSS to Develop Compatible
Supportive Designs
1

2. Context Sensitive Solutions in Transportation
Goal: Excellence Planning, Environmental Analysis and Design
Excellent transportation design
• Satisfies stakeholder purpose, needs, and vision
– Established early
– Refined as process advances
• Safe for users and community
• Harmonious with community
• Supports other community objectives
• Preserves environmental values and resources
2

3. Context Sensitive Solutions in Transportation
Process (Review) Planning, Environmental Analysis and Design
Project development process
• Determine context
– Existing conditions
•Physical
– Roadway, transitway, pathway
– Roadside, streetside, wayside
– Adjacent development
» Context zones
» Land use site design
» External factors
•Activity
– Transportation facility
– Roadside, streetside, wayside
– Adjacent land, buildings
3

4. Context Sensitive Solutions in Transportation
Process (Review) Planning, Environmental Analysis and Design
Project development process (cont.)
• Determine context (cont.)
– Environment (relevant)
• Physical
• Social
– Planed changes
– External factors
CS3 – context sensitive sustainable
solutions (Oregon DOT version)
4

5. Context Sensitive Solutions in Transportation
Process (Review) Planning, Environmental Analysis and Design
Project development process (cont.)
• Identify issues, opportunities, constraints, threats,
strengths, weaknesses
– Issues – concerns, problems, questions, uncertainties
– Opportunities – what could occur (physical, operational,
policy, transportation, development, economic, etc.)
– Constraints – limitations on opportunities
– Threats – negative factors or prospects
– Strengths – positive attributes on which to build
– Weaknesses – shortcomings to strengthen
5

6. Context Sensitive Solutions in Transportation
Process (Review) Planning, Environmental Analysis and Design
Project development process (cont.)
• Identfy goals, objectives, core values
– Desired outcomes – Core values
•Goals (general statements) •Aesthetics
– Mobility and access •Safety
– Economic development
•Character
– Land development
– Activity
•Etc.
– Other
•Objectives
– More detailed statements
6

7. Context Sensitive Solutions in Transportation
Process (Review) Planning, Environmental Analysis and Design
Project development process (cont.)
• Select criteria for evaluation, prioritization
– Base on
•Objectives •Mobility
•Issues •Socio-econimic
•Opportunities •Environmental
•Concerns •Cost-effectiveness
•Environmental impacts •Other
7

8. Context Sensitive Solutions in Transportation
Process (Review) Planning, Environmental Analysis and Design
Project development process (cont.)
• Vision
– Outcome from goals
•Functional
•Appearance
•Resulting conditions
8

9. Context Sensitive Solutions in Transportation
Project Development Planning, Environmental Analysis and Design
Develop alternatives
• Range
• Design criteria
• Approach
• Flexibility
• Components
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10. Context Sensitive Solutions in Transportation
Project Development Planning, Environmental Analysis and Design
Develop alternatives
• Range in magnitude
– “No build”
•May include improvements elsewhere in system
– Operational (TSM) improvements
– Minor
– Full “build”
• Range in type
– Modal
– Alignment
– Type of facility
– Extent of improvement
– Relationship with adjacent development
10

11. Context Sensitive Solutions in Transportation
Project Development Planning, Environmental Analysis and Design
Develop alternatives
• Design criteria
– AASHTO green book (using flexibility)
– AASHTO, FHWA Flexibility in Highway Design
– State DOT design manual
– City/county public works design manual
– Local agency guidelines (incl. zoning overlays)
– Modal guidelines (ITE CSS for walkable
communities)
• Ped – AASHTO ped guide
• Bike – AASHTO bike facilities guide
• Bus – TCRP 19, 33, 117 (pending
TCRP D-09
• Rail – TCRP 17, 69 guide)
– Landscaping
11

12. Context Sensitive Solutions in Transportation
Project Development Planning, Environmental Analysis and Design
Develop alternatives
12

13. Context Sensitive Solutions in Transportation
Project Development Planning, Environmental Analysis and Design
Develop alternatives
• Components
– Traveled way – Design each
– Adapt per activity
– Streetside, roadside, wayside
– Enhance each to work
– Land uses together
– Sense of place
• Urban design
• Parks
• Historic features
• Social fabric
• Arts and activity
13

14. Context Sensitive Solutions in Transportation
Decision-Making Context Planning, Environmental Analysis and Design
Caltrain improvements – S.F. peninsula line
TRANSIT THE
BUILT ENVIRONMENT HSR
SERVICES PROJECT
Alignment Alignment
WHAT Land Use Services Vehicles
Circulation Vehicles
TOD Vehicles Operations
DECISIONS? Connectivity
Operations
Stations Stations
Services Services
WHO City Councils Transit Agency JPB/CHSRA Boards
DECIDES? Board of Supervisors Federal agencies CHSRA Board
Boards
Elected officials Federal agencies
PRP Elected officials
Customers Customers
Customers
Facilitate consider
COMMUNITY Incorporate community community input
Direct engagement
INFLUENCE community engagement in decisions
input into
decisions Regional/state Statewide
accountabilility accountability

15. Context Sensitive Solutions in Transportation
Project Development Planning, Environmental Analysis and Design
Evaluate
• One measure per objective or issue
– Quantifiable (with available data)
– Sensitive to changes in performance
• Can be categorical or ratio
• Need quantification methodology
• Can work within Delphi process
15

16. Context Sensitive Solutions in Transportation
Project Development Planning, Environmental Analysis and Design
Evaluate – Option: Delphi process
• Combines performance and importance
• One measure per criterion
– Objective
– Issue
• Quantified in ratio scale
• Criteria weighted per stakeholder input
– Initial
– Again after interim results
16

17. Context Sensitive Solutions in Transportation
Project Development Planning, Environmental Analysis and Design
• Delphi example
(or other evaluation table)
17

18. Context Sensitive Solutions in Transportation
Project Development Planning, Environmental Analysis and Design
Evaluation
• Converge by narrowing, refining alternatives
1. Distinct ranging alternatives
Cycle
2. Workable more detailed alternatives 1.Formulate/
refine
2.Evaluate
3. (optional) Variations on final alternative(s) 3.Discuss
EIS
4.Narrow
4. Preferred alternative
5. Develop preliminary design
18

19. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Communities want
• Flexibility
• Compatibility with adjacent land uses
• Balanced land use/transportation functions
• Safe and attractive streets
• Multimodal facilities
• Streets that are quality public space
19

20. Context Sensitive Solutions in Transportation
FDOT TDLC Roads* Planning, Environmental Analysis and Design
*Transportation design for livable communities
Examples of flexible DOT design criteria
Minimum lane widths
20

21. Context Sensitive Solutions in Transportation
FDOT TDLC roads Planning, Environmental Analysis and Design
Techniques to
support non-drive
modes
21

22. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Tenets of CSS
• Balance
– Safety
– Mobility
– Community objectives
– Environment
• Multimodal
• Involve public, stakeholders
• Interdisciplinary teams
• Flexibility in design
• Incorporate aesthetics 22

23. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Placemaking
• Community-based approach to the development and
revitalization of cities and neighborhoods
• Placemaking:
– Unique places with lasting value
– Compact, mixed-use
– Pedestrian and transit oriented
– Strong civic character
– Contributes to economic development
23

24. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
ITE framework
• Context zones:
– Suburbs to downtowns
• Street classification:
– Functional class
– Thoroughfare type
•Boulevard
•Avenue
•Street
• Compatibility
24

25. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Context Zones – An Organizing System for
Thoroughfare Design
Graphic source: Duany Plater-Zyberk and Company
Source: Duany Plater-Zyberk and Company
Source: Context Sensitive Solutions in Designing Major Urban Thoroughfares for Walkable Communities

26. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Features that create context
• Land use
– Defines urban activity
– Major factor in design criteria
• Site design
– Arrangement of buildings, circulation, parking and landscape
– Vehicle or pedestrian-orientation
• Building design
– Height, massing shape context
– Create enclosure/pedestrian interest
26

27. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Land use influence
• Major factor in thoroughfare design
• Influences:
•Travel demand
•Activity in roadside
•Width of roadside
•On-street parking
•Target speed
•Freight and transit
27

28. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Site design
Feature Auto Oriented Pedestrian Oriented
Building – Set well back into – Oriented to, and adjacent to
Orientation and private property street
Setback – Oriented to parking or – Direct pedestrian entrance
landscape on street
– Integrated with street using
stoops, arcades, cafes
Parking Type and – Surface lot between – Under or behind building
Orientation buildings and street access by alleys
– Structured
– On-street
Block Length - Large blocks, often with - Short blocks
no public throughway - High connected network
- Superblocks
28

29. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Building design
• Significant contributor to
context defined by:
– Height and thoroughfare
enclosure
– Width
– Scale and variety
– Entries
29

30. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Street enclosure
• Building height to
thoroughfare width
ratios:
– 1:4 suburban
– 1:2-1:3 urban
• Pedestrians first
perceive enclosure at a
1:4 ratio
30

31. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
CSS tenet - thoroughfare design changes as
context changes
The thoroughfare both responds to and contributes to
shaping the context and defining the place
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32. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Thoroughfare types
• Three classifications:
– Boulevard
– Avenue
– Street
• Basis for:
– Physical configuration
– Design criteria
– Design speed
32

33. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Functional classification in thoroughfare design
• Function and role in the network
– Continuity
– Trip purpose and length
– Level of land access
– Type of freight
– Types of public transit
• Design controls
– Design speed for sight distance
– Horizontal and vertical curvature
33

34. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Relationship: functional classification and thoroughfare type
34

35. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Thoroughfare type in design
• Design criteria
– Target speed (desirable operating speed)
• Physical configuration
– With surrounding context
• Dimensions for:
– Roadside
– Traveled way
– Intersections
35

36. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Thoroughfare type characteristics
36

37. Context Sensitive Solutions in Transportation
FDOT TDLC Roads Planning, Environmental Analysis and Design
Speed reduction
techniques
37

38. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Boulevard
• Divided arterial (4+ lanes)
• Target speed (35 mph or less)
• Through and local traffic
• Serve longer trips
• Access management
• Major transit corridor
• Primary freight route
• Emergency response route
• Limited curb parking
38

39. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Boulevard
39

40. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Multi-way boulevard
• Characterized by:
– Central roadway for through traffic
– Parallel roadways access abutting property, parking,
and pedestrian and bicycle facilities
– Parallel roadways separated from the through lanes
by curbed islands
• Require significant right-of-way
• Special treatment of intersections
40

41. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Multi-way boulevard
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42. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Avenue
• Arterial or collector (4 lanes max)
• Target speed (30 to 35 mph)
• Land access
• Primary ped and bike route
• Local transit route
• Freight - local deliveries
• Optional raised landscaped median
• Curb parking
42

43. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Street
• Collector or local street (2 lanes)
• Target speed (25 mph)
• Land access primary function
• Designed to:
– Connect residential neighborhoods
– Connect neighborhoods with
commercial districts
– Connect local streets to arterials
• May be commercial main street
• Emphasizes curb parking
• Freight restricted to local deliveries
43

44. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Changing Thoroughfare & Context
• Arterial Street
• C-3: Suburban
Source: TJPDC, VDOT, City of Charlottesville, & Albemarle Co.
CD+A, Meyer, Mohaddes, & Urban Advantage Existing Conditions

45. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Changing Thoroughfare & Context
• Boulevard Thoroughfare
• C-4: General Urban
Source: TJPDC, VDOT, City of Charlottesville, & Albemarle Co.
CD+A, Meyer, Mohaddes, & Urban Advantage Alternative Future with Initial Network

46. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Changing Thoroughfare & Context
• Avenue Thoroughfare
• C-5: Urban Center
Source: TJPDC, VDOT, City of Charlottesville, & Albemarle Co.
CD+A, Meyer, Mohaddes, & Urban Advantage Alternative Future with Potential “Full” Network

47. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Design controls
• Speed
• Design vehicle
• Functional class
• Location
• Sight distance
• Horizontal / vertical alignment
• Access management
• Pedestrians and bicyclists
47

48. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Speed definitions
• Target speed
– Desirable operating speed in specific context
– Balances
•Vehicle mobility
•Safe environment
– Usually posted speed limit
– In CSS set by context and thoroughfare type
• Design speed
– Governs certain geometric features
– Usually set by functional classification
48

49. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Design vs. Control Vehicle
• Design Vehicle • Control Vehicle
– Accommodated without – Encroachment allowed
encroachment – Turns infrequently
– Turns with considerable – Example: emergency
frequency vehicle
– High volumes in
opposing lanes
– Example: bus
49

50. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Emergency vehicle operations
• Turning capability
• Access (clear areas)
– Building entrances
– Hydrants
– Walls
• Mountable median crossings (long blocks)
• Work with fire department
50

51. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
CSS vs. conventional design
Conventional CSS Approach
Context: Urban Context:
Urban Suburban
Rural General Urban
Urban Center
Urban Core
Design criteria based primarily Design criteria based primarily
on: on:
Functional class Community objectives
Design speed Thoroughfare type
Travel demand forecasts Functional class
Level of service objectives Adjacent land use
51

52. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Speed and capacity of urban streets
• Address capacity issues with:
– Network capacity
– Synchronized signal timing
– Access management
– Turn lanes
– Other operational refinements
• Address safety:
– Case-by-case basis
52

53. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
CSS design process
53

54. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Thoroughfare Components
Roadside
54

55. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Considerations in cross-section design
• Local objectives
• Stakeholder priorities
• Adjacent activities
• Functional class
• Context zone and
thoroughfare type
• Modal requirements
• Other conditions
– Right-of-way
– Traffic volumes
– Vehicle mix
55

56. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Stages in cross-section design
1. Establish general parameters based on:
– Context zone
– Thoroughfare type
– Select starting cross-section
2. Determine number of lanes based on:
– Community objectives
– Thoroughfare type
– Long-range transportation plan
– Corridor/network capacity analysis
– Maximum 6 lanes in walkable urban areas
56

57. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Stages in cross-section design
3. Determine design and control vehicle
4. Identify transit, freight, and bicycle requirements
– Establish dimensions
5. Develop ideal cross-section - compare to ROW
– Acquire ROW or narrow design elements, or
– Widen high priority elements to match ROW
– Avoid combining minimal widths
57

58. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Designing in constrained ROW
• Prioritize design elements
• Develop sections
– Optimal – unconstrained
– Predominant – all priority elements
– Functional minimum – many priority elements
– Absolute minimum – highest priority only
• ROW width less than absolute minimum
– Acquire ROW incrementally
– Change thoroughfare type
58

59. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Lane widths
• Up to 35 mph: 10-12 feet
• Over 35 mph: 11-12 feet
• With buses: 11-12 feet
• Bike lanes: 5-6 feet (4 feet outside gutter pan)
• Parking: 7-8 feet
59

60. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Medians
• Functions
– Access management
– Pedestrian refuge
– Left turn lanes
– Aesthetics
• Widths
– 4-22 feet
• Landscaping
– Trees (45 mph or less)
• 6-10 foot medians - less than 4 inch caliper
• 1½ feet lateral clearance
60

61. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Transitions
• Geometric transitions (use AASHTO)
– Change in thoroughfare width
– Lateral shifts
– Lane drops
• Location: on tangent sections
• Context, visual, operational, environmental transition
– Speed zone transition
– Visual cues
• Urban design, land uses, building design, gateways, signs
– Change width of thoroughfare
61

62. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Excerpt from ITE CSS guide – cross-sections
6
2

63. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Streetside design
• From property line to face of curb
• Accommodates street activity
– Mobility
– Business
– Social
• Public space
63

64. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Urban streetside uses
• Movement of pedestrians
• Access to buildings/property
• Utilities/appurtenances
• Transit stops
• Landscaping
• Urban design/public art
• Sidewalk cafes
• Business functions
• Civic spaces (plazas, seating)
64

65. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Streetside components
• Streetside zones:
– Edge Zone
– Furnishings Zone
– Throughway Zone (ADA)
– Frontage Zone
• Function and dimensions vary
by context zone and adjacent
land use
65

66. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Streetside cross-section guidelines
C-4 w/ Predominantly Commercial Ground
Sidewalk Zone [1] C-6 and C-5 C-4 w/ Predominantly Residential Frontage
Floor Use
1.5 feet 1.5 feet
21.5 foot (recommended)
16.5 foot (recommended)
Edge 0.5 feet
19 foot (recommended)
2.5 feet at diagonal parking 2.5 feet at diagonal parking
12 foot (constrained)
12 foot (constrained)
8 feet
7 feet 7 feet
Boulevard
Furnishings (landscape strip w/ trees and grasses or
(trees in tree wells) (trees in tree wells)
groundcovers)
Throughway 10 feet 8 feet 8 feet
0 feet along lawn and groundcover
Frontage 3 feet 2.5 feet 1 foot along low walls, fences, and hedges
1.5 feet along facades, tall walls, and fences
Edge
Boulevard Without Parking
0.5 feet
18.5 foot (Recommended)
10 feet
Furnishings (landscape strip w/ trees and groundcovers or
THIS THOROUGHFARE TYPE NOT APPLICABLE TO THE PREDOMINANTLY low shrubs)
Throughway COMMERCIAL GROUND FLOOR LAND USES FOUND IN C-4 THROUGH C-6 CONTEXT 8 feet
ZONES
0 feet along lawn and groundcover
Frontage 1 foot along low walls, fences, and hedges
1.5 feet along facades, tall walls, and fences
1.5 feet 1.5 feet
Edge 0.5 feet
2.5 feet at diagonal parking 2.5 feet at diagonal parking
19.5 foot (recommended)
14.5 foot (recommended)
16 foot (recommended)
12.0 foot (constrained)
8 feet
12 foot (constrained)
With 6 feet 6 feet
(landscape strip w/ trees and grasses or
Parking trees in tree wells (trees in tree wells)
Furnishings groundcovers)
Avenue
Without 8 feet with 8 feet with 8 feet with
Parking buffer landscaping buffer landscaping buffer landscaping
Throughway 9 feet 6 feet 6 feet
0 feet along lawn and groundcover
Frontage 3 feet 2.5 feet 1 foot along low walls, fences, and hedges
1.5 feet along facades, tall walls, and fences
1.5 feet 1.5 feet
11.5 foot (recommended)
Edge 0.5 feet
16 foot (recommended)
16 foot (recommended)
12.0 foot (constrained)
2.5 feet at diagonal parking 2.5 feet at diagonal parking
12 foot (constrained)
5 feet
6 feet 6 feet
Furnishings (landscape strip w/ trees and grasses or
(trees in tree wells) (trees in tree wells)
Street
groundcovers)
Throughway 6 feet 6 feet 6 feet
0 feet along lawn and groundcover
Frontage 2.5 feet 6 2.5 feet 1 foot along low walls, fences, and hedges
6 1.5 feet along facades, tall walls, and fences

67. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Edge zone
• Interface with traveled way
• Functions
– Vehicle overhang and clearance
– Door opening area
– Wheelchair access at transit stops
• No (rural) clear zone width
• Lateral clearance
– 1½ ft from curb face
67

68. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Furnishings zone
• Buffers pedestrians from traveled
way
• Functions
– Street furniture, public art
– Utilities (within zone)
– Transit stops
– Lighting
– Public spaces (seating)
– Business space (cafes)
– Landscaping
• Safe landscaping
– Sight lines (CPTED)
– Sight distances
68

69. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Throughway and frontage zones
• Throughway zone
– Clear area for pedestrian travel
– ADAAG requirements
– No utilities
• Frontage zone
– Area adjacent to property line
– “Shy” distance from buildings
– Business space (cafes, signs)
– Landscaping
– Seating
– Building access
69

70. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Clear zones on urban thoroughfares
• Defined as an edge zone clear of fixed objects
• Less consequence than rural context
– Lower speeds
– Parked vehicles
• Often not practical in urban areas
• Rural standards not used in urban walkable
areas
70

71. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Driveways
• Minimize in high pedestrian activity areas
• Maintain sidewalk cross slope
Best If necessary 
71

72. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Traveled way
• Central portion of thoroughfare between curbs
• Provides for movement of vehicles
• Interface with roadside via on-street parking
72

73. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Traveled way components
• Functions, modes
• Widths, ROW allocations
• Through travel and turn lanes
• Access management
• Parking, transit stops, bike lanes
• Emergency vehicle operations
• Transitions
• Mid-block crosswalks
• Medians, pedestrian refuge islands
73

74. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Lane widths
• Recommended practice
– Urban freeways:
• 12 feet normal
• 11 feet constrained
– Arterials and collectors
•10–11 feet on arterials and collectors
• 12-feet under special circumstances
– Based on:
• Target speed
• Design vehicle
• Right-of-way
• Width of adjacent parking and bicycle lanes
74

75. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Medians Recommended Median Widths on Low Speed
Thoroughfares (35 mph or less)
• Recommended practice Thoroughfare Type
Minimum
Width
Recommende
d Width
Median for access control
Arterial Boulevards and Avenues
4 ft. 6 ft.
Collector Avenues and Streets
Median for pedestrian refuge
Arterial Boulevards and Avenues
6 ft. 8 ft.
Collector Avenues and Streets
Median for street trees and lighting
Arterial Boulevards and Avenues
6 ft. 10 ft.
Collector Avenues and Streets
Median for single left-turn lane
Collector Avenues and Streets 10 ft. 14 ft.
Arterial Boulevards and Avenues 12 ft. 16-18 ft.
Median for dual left turn lane
Arterial Boulevards and Avenues 20 ft. 22 ft.
75

76. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Street trees - Recommended practice
• In medians
– Min. median width
• 6 feet for up to 4” caliper trees
• 10 feet for larger trees
– Avoid trees larger than 4” caliper
• Speed > 45 mph
• Or use barrier
76

77. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Bicycle lanes
• Recommended practice
– Combined with on-street parking = 13 feet
– Without on-street parking = 6 feet
77

78. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
On-street parking – recommended practice
Recommended Parallel Parking Lane Widths
Thoroughfare Type in C-3 through C-6 Context Zones
Parallel Parking Lane Width (commercial and residential areas)
Arterial Boulevard (commercial) 8 ft.
Arterial Boulevard (residential) 7 ft.
Parallel Parking Lane Width (residential areas)
Arterial Avenue 7 ft.
Collector Avenue and Street 7 ft.
Parallel Parking Lane Width (commercial areas)
Arterial Avenue 8 ft.
Collector Avenue and Street 8 ft.
78

79. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
• Mid-block crosswalks - Recommended practice
– Locate so crossings are 200-300 feet apart
– Significant pedestrian demand
– Criteria
• 12,000 ADT or less
• 15,000 ADT with median refuge
• Speed less than 40 mph
• Adequate sight distance
79

80. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Urban intersections
• General principles
– Minimize conflicts between modes
– Minimize pedestrian exposure
– Provide crosswalks on all
approaches
– Minimize curb radii consistent with
design/control vehicle
– Ensure good visibility
– Balance vehicle LOS with
pedestrian convenience and safety
80

81. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
• Urban intersections - Design elements
– Through and turning lanes
– Intersection sight distance
– Medians
– Curb return radii
– Design vehicle
– Channelized right turns
– Modern roundabouts
– Crosswalks and refuges
– Curb extensions
– Bicycle lane treatment
– Bus stops
– Traffic signals
81

82. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Urban intersections
• Avoid large undefined open spaces
Source: City of Palo Alto
CD+A, FPA, and Urban Advantage 82

83. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Urban intersections - Creating opportunities to
improve context
Source: City of Palo Alto
CD+A, FPA, and Urban Advantage 83

84. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Intersections – simplify for all modes
84

85. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
• Intersections – Curb return radius - recommended
practice
– Consider
• Design vehicle
• Effective width
• Curb return radii
– Minimum radius = 5 feet
– Use 10-15 feet radius
• High ped volumes
• Low turning volumes and speed
• Bike/parking lanes create higher effective radii
85

86. Context Sensitive Solutions in Transportation
FDOT TDLC Roads Planning, Environmental Analysis and Design
Curb extension and effective corner radius
86

87. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Curb extensions
• Improve visibility
• Reduce crossing width
• On streets with parking
• Recommended practice
– Extend curb line 1 ft. less than parking
width
– Curb return radius for control vehicle
– Use with bus stops to increase waiting
area
87

88. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Channelized right turns - recommended
practice
• Generally discouraged in walkable
environments
• Signalized intersections with heavy right
turns
• Low pedestrian volumes
• Where pedestrian volumes high – eliminate
or install pedestrian signal
• Low-angle turn
• Clear visibility
• Illumination
88

89. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Roundabouts - recommended practice
Minimum Urban Urban Urban
“Mini- Compact Single-Lane Double-Lane
Parameter Roundabout” Roundabout Roundabout Roundabout
Maximum Entry Speed (mph) 15 15 20 25
Bus and WB-67 with
Bus and
Single-unit lane
Design Vehicle Single-Unit WB-50
truck drive encroachment
Truck
over apron on truck apron
Inscribed circle diameter (feet) 45 to 80 80 to 100 100 to 130 150 to 180
Maximum number of entering
1 1 1 2
lanes
Typical capacity (vehicles per
day entering from all 10,000 15,000 20,000 40,000
approaches)
Applicability by Thoroughfare Type:
Not Not Not
Boulevard Applicable
Applicable Applicable Applicable
Not Not
Arterial Avenue Applicable Applicable
Applicable Applicable
Not
Collector Avenue Applicable Applicable Not Applicable
Applicable
Street Applicable Applicable Applicable Not Applicable
89

90. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
9
0

91. Context Sensitive Solutions in Transportation
Developing Designs Planning, Environmental Analysis and Design
Roundabouts
91

92. Context Sensitive Solutions in Transportation
Design Exceptions Planning, Environmental Analysis and Design
Design exceptions – 13 controlling criteria
– Design/target speed • Vertical alignment
– Lane width • Grade
– Shoulder width • Stopping sight distance
– Bridge width • Vertical clearance
– Horizontal alignment • Horizontal clearance
– Superelevation • Structural capacity
– Cross slope
• Needed when
– Cannot meet minimums in applicable design manual
– Reasonable alternative design will work safely
92

93. Context Sensitive Solutions in Transportation
Frequent design Exceptions Planning, Environmental Analysis and Design
Number state DOTs reporting frequent design exceptions by criterion
NCHRP Synthesis 316
93

94. Context Sensitive Solutions in Transportation
Design Exceptions Planning, Environmental Analysis and Design
Consider trade-offs
• Mobility, access
• Road user needs
• Environmental impacts
• Capital and operating costs
• Safety
• Aesthetics
• Local considerations
94

95. Context Sensitive Solutions in Transportation
Design Exceptions Planning, Environmental Analysis and Design
Design Domain and Risk
Speed or Volume
Lower limit of extended
design domain – new
roads
Increasing liability risk,
Decreasing scope Extended Normal
for defense
Design Domain
Lower limit of extended
design domain –
existing roads
Standard Design Criteria
Minimums
Adapted from: O. Arndt, R. Cox, “Using an Enlarged Design Domain for
Road Restoration Projects,” Queensland Department of Main Roads, 2006.
95

96. Context Sensitive Solutions in Transportation
Design Exceptions Planning, Environmental Analysis and Design
• Strong case
– Show criteria not applicable
•Project can be safe not following criteria
•Environmental or community needs prohibit meeting
criteria
•Criteria impractical to meet
– Weak case
•Saves money
•Saves time
•Designer found loop hole
•Design similar to other existing designs
96

97. Context Sensitive Solutions in Transportation
Design Exceptions Planning, Environmental Analysis and Design
Minimum documentation
• Established design criteria
• Reasons criteria cannot be met
• Why proposal is most applicable
• Applicable background information
• Pertinent information
– Safety assessment
– Operations
97

98. Context Sensitive Solutions in Transportation
Design Exception Form Planning, Environmental Analysis and Design
98

99. Context Sensitive Solutions in Transportation
Design Exceptions Planning, Environmental Analysis and Design
Documentation must be
• Deliberative
• Defensible
• Clearly written
• Explicitly evaluate safety
– Who is at risk
• Motorists, pedestrians, etc.
– Exposure
• Traffic volumes
• Location
– Extent of exception
– How risk is managed (solely relying on standards does not
guaranty facility free of risk)
99

100. Context Sensitive Solutions in Transportation
Design Exception Process Planning, Environmental Analysis and Design
Florida DOT design and utility
exception process
100

101. Context Sensitive Solutions in Transportation
Design Exceptions Planning, Environmental Analysis and Design
Rule of thumb for success
• No reasonable, feasible, practical solution available that
meets criteria, or
• Selection of proposed criteria is advantageous and
results in overall superior design
and
• Use of proposed criteria is not expected to unduly
degrade or hinder safety or operational performance of
the proposed facility
101

102. Context Sensitive Solutions in Transportation
Design Exceptions Planning, Environmental Analysis and Design
Reference (available
on-line):
102

103. Context Sensitive Solutions in Transportation
Design References Planning, Environmental Analysis and Design
AASHTO
• A Guide for Achieving Flexibility in Highway Design, 1st Edition
• A Policy on Geometric Design of Highways and Streets, 5th Edition
• Guide for the Planning, Design, and Operation of Pedestrian Facilities, 1st Edition
• Guide for High-Occupancy Vehicle (HOV) Facilities, 3rd Edition
• Guide for Park-and-Ride Facilities, 2nd Edition
• Guide for the Development of Bicycle Facilities, 3rd Edition
• Roadside Design Guide, 3rd Edition
• Roadway Lighting Design Guide
• Design for Transit Vehicles and Facilities on Streets and Highways (pending from TCRP D-09)
ITE
•Context Sensitive Solutions in Designing Major Urban Thoroughfares for Walkable Communities (2nd
edition pending – retitled to Designing Walkable Urban Thoroughfares: A Context Sensitive Approach)
•Urban Geometric Design Handbook
•Guidelines for Driveway Location and Design
•Guidelines for Neighborhood Street Design
TRB
•A Guide for Transportation Landscape and Environmental Design (update pending)
•Access Management Manual
103

104. Context Sensitive Solutions in Transportation
Class Project Discussion Planning, Environmental Analysis and Design
• Projects to be
– Presented Class 28
– Submitted at start of Class 29
• Student questions?
104