INTERSECTION DESIGN...4-37 Why roundabouts are safer for all users: •Slow speed: Deflection, truck apron, splitter islands, “reverse super” •Reduced conflicts •No left turns

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?