intersection design...4-37 why roundabouts are safer for all users: •slow speed: deflection, truck...
TRANSCRIPT
4-1
INTERSECTION
DESIGN
Bicycle Facility Workshop – Intersections
4-2
Avoid unusual conflicts
Provide direct path for cyclists, close to that
of motor vehicles
Bicyclists should be visible; their movements
should be predictable
Simple right angles best for bicyclists
Intersections
Bicycle Facility Workshop – Intersections
4-3
Bigger isn’t always better…
Albuquerque NM Bicycle Facility Workshop – Intersections
4-4Albuquerque NM Bicycle Facility Workshop – Intersections
4-5Albuquerque NM Bicycle Facility Workshop – Intersections
4-6
Compact urban intersections are better
Philadelphia PA Bicycle Facility Workshop – Intersections
4-7
Skew decreases driver’s ability to see cyclists
Bicycle Facility Workshop – Intersections
4-8
Right angle increases visibility
Bicycle Facility Workshop – Intersections
4-9
Shallow angle/poor visibility not good for cyclists
Honolulu HI Bicycle Facility Workshop – Intersections
4-10
Driver relies on rear-view mirror to see traffic
Honolulu HI Bicycle Facility Workshop – Intersections
5-11
Bicycle Detection at Signals
This figure indicates where cyclists should
wait in order to actuate the signal
Bicycle Facility Workshop – Intersections
4-12
Loop detector in bike lane detects cyclists
Bicycle Facility Workshop – Intersections
5-13
MUTCD standard for signal
loop marking for bicyclists
(Section 9C.05)
Bicycle Facility Workshop – Intersections
4-14
Loop detector in travel lane with cyclist stencil
Portland OR Bicycle Facility Workshop – Intersections
4-15
Good advice:
“Lean for the green”
Bicycle Facility Workshop – Intersections
4-16
Better:
Push button close to curb
Not good:
Requires dismounting
What about ped-style push buttons for cyclists?
Bicycle Facility Workshop – Intersections
4-17
Summary of provisions for
bicyclists at signals
Bicycle Facility Workshop – Intersections
4-18
Always place bike lane to left of RTL to
Separate conflicts
Make bicyclists’ movements more predictable
Take advantage of speed difference
Bike lane & right-turn lane channelization
Bicycle Facility Workshop – Intersections
4-19Corvallis OR Bicycle Facility Workshop – Intersections
4-20
Other scenario
1. RTL created by dropping parking
Bicycle Facility Workshop – Intersections
4-21Corvallis OR Bicycle Facility Workshop – Intersections
4-22Corvallis OR Bicycle Facility Workshop – Intersections
4-23Corvallis OR Bicycle Facility Workshop – Intersections
4-24
Other scenario
2. RTL created by dropping
through lane
In this case, bicyclists must
move over across a lane to
reach through bike lane
Bicycle Facility Workshop – Intersections
4-25
Bicyclists must cross a lane to reach through bike lane
Portland OR Bicycle Facility Workshop – Intersections
4-26
Bicyclists must cross a lane to reach through bike lane
Portland OR Bicycle Facility Workshop – Intersections
4-27Portland OR Bicycle Facility Workshop – Intersections
4-28
Place bike lane correctly even if it ends past intersection
Bicycle Facility Workshop – Intersections
4-29
A combined right turn lane and through bike lane is a
reasonable compromise in constrained conditions
Salem OR Bicycle Facility Workshop – Intersections
4-30
Cars will use the bike lane area when bicyclists
are not there – note the customized sign
Shared lane markings may
ultimately be a better solution
Bicycle Facility Workshop – Intersections
4-31
Roundabouts:
Making them work for
bicyclists
Bicycle Facility Workshop – Intersections
4-32
A roundabout is a type of intersection control
Clearwater FL Bicycle Facility Workshop – Intersections
4-33
A roundabout is not:
1. A New England style rotary, with large size & high speeds
Augusta ME Bicycle Facility Workshop – Intersections
4-34
A roundabout is not:
2. A Washington DC style circle, with traffic signal controls
Washington DC Bicycle Facility Workshop – Intersections
4-35
A roundabout is not:
3. A traffic-calming mini circle
Portland OR Bicycle Facility Workshop – Intersections
4-36Paris FR
A roundabout is not:
4. Paris
Bicycle Facility Workshop – Intersections
4-37
Why roundabouts are safer for all users:
• Slow speed: Deflection, truck apron, splitter islands, “reverse super”
• Reduced conflicts
• No left turns
• Yield on entry
CRF (all users):
• About 54% overall
• 27% pedestrian crashes
• Up to 76% fatals and serious injuries
Clearwater FL Bicycle Facility Workshop – Intersections
4-38
Essential roundabout characteristics
Slow speed entry = yield
Slow speed exit
Truck apron
Splitter island
Crosswalk 1 car
length back
Lots of deflection = slow
speeds throughout
Separated sidewalks
direct peds to crosswalks
Bend OR Bicycle Facility Workshop – Intersections
4-39
What does it take to make roundabouts
work for bicyclists?
Slow speeds – lots of deflection; truck apron
Simple, single lane, throughout
Splitter islands
“Escape ramps” for multi-lane roundabouts
Bicycle Facility Workshop – Intersections
4-40
Roundabouts:
Designing to
accommodate
Bicyclists
Bicycle Facility Workshop – Intersections
4-41
End bike lane to encourage cyclist to enter roadway
Bend OR Bicycle Facility Workshop – Intersections
4-42
End bike lane to encourage cyclist to enter roadway
Bend OR Bicycle Facility Workshop – Intersections
4-43
Slow speed allows cyclists to share roadway
Bend OR Bicycle Facility Workshop – Intersections
4-44Bend OR Bicycle Facility Workshop – Intersections
4-45Bend OR Bicycle Facility Workshop – Intersections
4-46Bend OR Bicycle Facility Workshop – Intersections
4-47Bend OR Bicycle Facility Workshop – Intersections
4-48
What if a cyclist doesn’t want to enter the
roundabout?
Bend OR Bicycle Facility Workshop – Intersections
4-49Bend OR Bicycle Facility Workshop – Intersections
4-50Bend OR Bicycle Facility Workshop – Intersections
4-51
Questions?