Transcript Toole Bicycle Guide.ppt

Revision to the AASHTO Guide for the
Development of Bicycle Facilities
Presentation by:
Jennifer Toole
Principal Investigator
July 21st, 2009
NCHRP Project 15-37
• Some history
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– This will be the 4th edition of the Guide
– Last Guide – 1999, largely written in 96-98
– John LaPlante and Jennifer Toole – co-authors
– Survey to update Guide – 2004
Chair of NCHRP Panel – Dwight Kingsbury, Florida DOT
Panel includes:
 7 members from State DOTs
 2 FHWA representatives
 3 members from local agencies
 1 consultant
Team and Panel
Project Team
• Jennifer Toole, Principal
Investigator
• Eric Mongelli, P.E.
• William Schultheiss, P.E.
• Nick Jackson
• Subject Matter Experts:
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John LaPlante, P.E., PTOE
Michael Moule, P.E.
Michael Ronkin
Mia Birk
Matthew Ridgeway
Shawn Turner, P.E.
Srinivasa Sunkari, P.E.
Bill Hunter
Panel
• Dwight Kingsbury, Chair
• Denise Chaplick
• David Church, P.E.
• Ann Do
• Eric Glick
• Fred Glick, RLA
• Thomas Huber
• Mary Meletiou
• Richard Moeur, P.E.
• William Prosser, P.E.
• William Riccio, Jr., P.E.
• Cara Seiderman
• Richard Pain
Project Timeline
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NCHRP Project Completion – Fall 2009
Basis for Content Changes
• Reviewed findings of scoping study (survey)
• Reviewed a significant body of research and
literature
• Drew upon our own experience using the
Guide on a daily basis
• Drew upon the experience of our Team and
Panel
This presentation will cover the highlights of
new and revised content of design chapters.
Issues NOT addressed by this Guide
• Contrasting colored pavements
• Bike boxes
• Cycle tracks
• Raised bike lanes
• Bicycle signal heads
Important source for design chaps
New Chapter
Bicycle Operation and Safety
• Sets the stage for Design Chapters
• Organizes info on design vehicle
• Overview of traffic principles for
bicycles
– Positioning on the roadway in
different situations
• Causes of bicycle crashes
– Urban vs. rural
– Young vs. adult riders
– Etc.
Key Dimensions Chart
User Type
Typical upright adult bicyclist
Recumbent bicyclist
Tandem bicyclists
Bicyclist with child trailer
Hand bicyclist
Inline skater
Feature
Physical Width (95th percentile)
Physical length
Physical height of handlebars (typ dimension)
Eye height
Center of Gravity (approximate)
Operating width (minimum)
Operating width (preferred)
Operating height (minimum)
Operating height (preferred)
Physical length
Eye height
Physical length (typical dimension)
Physical width
Physical length
Eye height
Sweep width
Dimension
US Cust
30 in
70 in
44 in
60 in
33-40 in
48 in
60 in
100 in
120 in
82 in
46 in
96 in
30 in
117 in
34 in
60 in
Metric
0.75 m
1.8 m
1.1 m
1.4 m
0.8-1.0 m
1.2 m
1.5 m
2.5 m
3.0 m
2.2 m
1.2 m
2.4 m
0.75 m
3.0 m
0.9 m
1.5 m
Chapter 4
Design of On-Road Facilities
• More guidance on shared lanes, general roadway
compatibility
• New sections on shared lane markings, bicycle
boulevards and wayfinding signage
• More context and detail for bike lane guidance
– More info on bike lanes with various roadway
configurations
– More info on bike lanes at intersections
• New section on retrofitting existing roadways to
accommodate bicycles
Shared Lanes
• Roads do not need a special bicycle facility to be
compatible
• Design guidance for wide outside
lanes is same (14’)
• Guidance on selecting appropriate
type of bikeway given traffic
volumes and speeds (Bicycle LOS)
Shared Lane Markings
• Coordinated with MUTCD
Locations to use SLM’s
• Adjacent to on-street
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parking to position cyclist
outside of door zone
In wide lanes to position
away from curb
Narrow lanes
Multi-lane roads where
there is no room for bike
lane
Climbing lanes (on downgrade) paired with bike
lane
Climbing Lanes
Where NOT to use SLM’s
• On paved shoulders or bike lanes
• Where the speed limit exceeds 35 mph
Paved Shoulders
• Shoulder width:
– 4 ft. min, 5 ft against vertical face
– Wider if there are higher speeds/volumes
(per BLOS)
• At shoulder bypass lanes – carry shoulder space
through T-intersections
Bicycle Lanes
• Markings are required, but signs are optional
• More guidance for markings
at bus stops
• Both symbols still allowed
Left-Side Bicycle Lanes
• Discussion of when left side bike lanes can be
beneficial on one-way streets:
– When there are a lot of left-turning bicyclists
– If the left-side lane would decrease conflicts,
i.e. with buses or
heavy right turn
volumes
Bicycle Lane Widths – DRAFT
• Same as last Guide – 5 ft standard width (4 ft with no
curb and gutter)
• Some caveats:
– 5 ft bike lane is sufficient assuming a 1 ft wide
gutter
– In states that use a 2 ft wide gutter, a 6 ft wide
bike lane is preferred, with 5 ft as a minimum
width in locations with lower speeds
– In extremely constrained, urban low speed
environments where 5 ft cannot be achieved and
there is no gutter, a 4 ft wide bike lane is
acceptable (assumes adjacent travel lane has been
narrowed to the minimum acceptable width)
Angled Parking
• Bike lanes not recommended at front-in angled parking
• Bike lanes are OK with back-in angled parking if parking
bays are sufficient
length
Typical bike lane markings
Bicycle Guide Signs
• Deemphasizes bike routes, they are not a facility type
• Guidance on all sign types
• Signs are not a substitute for good geometric design
• D-Series are below
Bicycle Guide Signs
M1-8 and M1-9 Series
Traffic Signals
• Significantly expanded guidance
• Formulas and diagrams based on new data
• Assumes one speed – 10 mph – rather than
different speeds for A, B and C bicyclists
• Appropriate to modify the minimum green
interval, all-red interval,
and extension time for
bicyclist speeds.
Bicycle Minimum Green
• Bicyclists require more time to clear intersection than
motorists
• More important where minor streets cross major roads
(may be a long distance with a short cycle length)
• Two choices:
– Program controller to provide BMG with a detector
– Increase minimum green for all vehicles
Detection for Bikes at Signals
• Provides more guidance on:
– Loop configurations that
best detect bicycles
– Sensitivity settings
– Use of upstream detectors
– Detector markings
Roadway Bridges
• Bridges should accommodate bicycles
• “Absence of bicycle accommodations on the
approach should not prevent the accommodation of
bicycles on the bridge.”
Bridge Railings
• In locations where bicyclists will operate in
close proximity to railings, should be a minimum
of 42” high.
• On bridges where bicycle speeds are likely to be
high and where a bicyclist could impact a
barrier at a 25 degree angle or greater, use 48”
railing.
Bicycles on Freeways
• Addresses considerations if bicycles are allowed
to operate on the freeway
• Addresses freeway interchange design
– Design junctions as right-angle intersections
if possible
Single Point Urban Interchange
Merge Ramp Options
Merge Ramp Options
Bicycles at Roundabouts
• Terminate bike lanes in advance (at least 100 ft)
• General design issues
– Low speed roundabouts are best (15-20 mph)
– Discourages use of multi-lane roundabouts
unless absolutely necessary
• For multi-lane roundabouts, provide opportunity
for bicyclist to exit roadway and use sidewalk
Multi-lane Roundabouts
Chapter 5
Design of Shared Use Paths
• New stand-alone chapter
• Reflects several significant studies:
– Characteristics of Emerging Trail and
Roadway Users
– Shared Use Path Level of Service
– Architectural Barriers Act Accessibility
Guidelines for Outdoor Developed Areas
– Safety Effects of Marked Versus Unmarked
Crosswalks at Uncontrolled Locations
• Fills missing gaps in the old Guide
Sidepath Guidance
• Consolidates discussion of SUP’s adjacent to
roadways – Clearly defines “sidepath”
– Expands discussion of operational problems
– Acknowledges reasons for building paths
adjacent to roadways
– Provides guidance on
when and where these
facilities are appropriate
– Provides design
guidance for those
locations
Sidepaths may be considered:
• Adjacent road has high speeds and volumes and
no practical alternatives for improving on-road
conditions or adjacent routes
• Sidepath is used for a short distance to connect:
– Pathway segments
– Local streets used as bicycle routes
• Sidepath can be built with few roadway and
driveway crossings
• Sidepath can be terminated in a bicycle
compatible location
Shoulders/clearances
• Graded shoulder of 3-5 ft recommended, max cross
slope of 1:6
• Minimum clearance of 2 ft to lateral obstructions
– Except at smooth features such as railings or
fences, 1 ft is acceptable
• Adjacent to hazards, 5 ft separation is desired
– Water hazards
– Downward slopes greater than 3:1
– Depending on height of embankment and
condition at bottom, railing may be needed
Safety
rail
guidelines
Design Speed
• Old Guide: 20 mph min design speed
• New Guide: “No single design speed” for all paths
– Consider types of users, terrain, path surface
• Guidelines:
– Generally should not be lower than 85th percentile
speed: 14 mph
– For longer segments in flat
areas: 18 mph
– Higher design speeds in
hilly terrain, up to 30 mph
Horizontal Alignment
• Horizontal curve formula is now based on lean
angle rather than superelevation
• By revising formulas
and using new design
speeds, min. curve
radius can be lower:
– Old Guide: 90-100 ft min
– New Guide: 60 ft
(18 mph design speed)
Speed Control on Paths
• Introduces concept of using geometric design
and traffic control to reduce user speeds, such
as curvature
• Recommends centerline stripe to reduce speeds
and address conflicts
• Depends on site specific context
Stopping Sight Distance
• New braking friction factor for bikes (0.16)
• Longer stopping distances but reduced design
speed offsets this
• Gives values for other users
Path-Roadway Intersections
• Significantly expanded guidance
• Explains the complexities of path-roadway
intersections:
− Fastest user must be considered on the approach
− Slowest user must be considered at the crossing
• Three intersection types:
– Midblock
– Sidepath
– Grade-separated
Mid-Block Intersections
• Geometric design issues
• Special issues with assignment of right-of-way
• Determining appropriate crossing measures
• Determining priority assignment
• Routine use of stop signs
• Evaluating sight distance and selecting type of control
• Midblock signalized intersections
• Examples
Example Yield Control for Path
Example Stop Control for Path
Design at Sidepath Intersections
• Based on Florida DOT research
• Reduce turning speeds at driveways and intersections –
tighter corner radii, avoid free-flowing movements,
provide median refuge islands, carry path surface across
driveway, etc.
• Reduce frequency of driveways
• Consider design to reduce path user speeds
• Employ measures on adjacent road to reduce speeds
Design at Sidepath Intersections
• Facilitate bicycle movements to/from road to pathway
• Keep crossings clear of obstructions
• Add stop or yield bars to instruct drivers crossing
pathway
• Design path termini to ensure proper operation of
bicyclists entering roadway
New Chapter
Bicycle Parking
• Planning for bicycle parking
• Short-term bicycle parking
– Location
– Design
– Special types of racks
• Long-term bicycle parking
Next up: AASHTO Ped Guide!
• NCHRP 20-7, Task 263
• Opinion Survey – OPEN ‘TILL JULY 31
• http://tinyurl.com/AASHTO-Ped-Guide
• Includes a literature review
• Project concludes in October
• Will provide an annotated outline for the next
Guide
Thank you!
Contact information:
Jennifer Toole
Toole Design Group
[email protected]