Newcastle cdt day 2 as delivered

DESIGNING FOR CYCLING BRIAN DEEGAN + JOHN DALES
Brian Deegan + John Dales
Designing for Cycling

Session 2 Agenda
12:30 Registration
13:00 Principles
13:20 Priority Junctions
13:40 Crossings
14:00 Roundabouts
14:20 Signal Junction Terms
14:40 Method of Control Exercise
15:00 Break
15:15 Signal Junctions
17:00 Finish

DESIGNING FOR CYCLING BRIAN DEEGAN + JOHN DALESDESIGNING FOR CYCLING BRIAN DEEGAN + JOHN DALES
Principles of Junction Design

Principles of Junction Design
Junctions need to be designed to
• Minimise delay
• Minimise hazard by managing conflicting
movements in time or space
• Accommodate all users
With specific reference to cycle traffic:
• Need to consider all cycle movements
• Minimise number of motor traffic lanes
• Reduce motor vehicle speeds
• Eliminate or manage conflict with motor traffic
• Raise drivers’ awareness of cyclists
• Guide cyclists’ and drivers’ movements

Integration and Segregation
• Integration can be appropriate when traffic speeds and flows are low
• Integrating cycle and motorised traffic minimises the number of conflicts
and can improve actual safety
• Segregated facilities necessary at busy/complex junctions
• Segregation should not mean a loss of priority for cycle traffic

Priority Junctions

Priority Junctions - Casualties
• Most common junction type
• 53% of cycle casualties (T-junctions,
cross-roads) 2011-13
• Cyclists vulnerable to turning motor traffic
Cycle KSIs at junctions (2011-2013):
• Vehicle turns right across cyclist path (14%)
• Vehicle turns left across path of cyclist (9%)
• Vehicle fails to give way (6%)

Priority Junctions - Issues
Issues for cyclists:
• Moving ahead through a priority junction:
• Turning right into and out of junctions:
• Any turn moving across more than one lane or one busy lane will be
uncomfortable.

• Reduce speed on link
• Reduce speed on turning
• Reduce number of traffic lanes
• Keep corner radii tight
• Use 90 degree approach
• Avoid left turn merges and diverges
• Closing side roads
• Making side roads one-way out
• Right turn refuges for cycles
Priority Junctions – Beneficial Measures

• Side Road Entry Treatments have
benefit for both pedestrians and cyclists
• TRL study showed significant reduction
in cycle collisions with SRET
• Reduce speed of traffic entering and
exiting minor road
• Beneficial when cycling is
o on carriageway,
o in cycle lane,
o in cycle track
Priority Junctions – Side Road Entry Treatment

Cycle Lanes and Symbols at Priority Junctions
• Use 1010 markings at junction
• Aim to provide extra 0.5m buffer
space past side roads
• If 1.5m lanes definitely use SRET
• Cycle lane may be coloured to
emphasise its presence
• If not possible to provide
adequate cycle lane, interrupt
lane at junction and use 1057
symbols in primary position

Cycle Lanes and Symbols at Priority Junctions

Segregated Lanes and Tracks at Priority Junctions
• Options for maintaining cycle priority through priority junctions:
– “Bending out”, giving space for turning vehicles to yield
– Track becomes lane at junction
– Continue track away from carriageway without deviation

Bi-directional Tracks at Side Roads Not Preferred

Bending Out - space to yield

Track Becomes Lane at Junction

Continue Track Without Deviation

Continuous Footway

Continuous Footway & Cycleway

Crossings

Crossings
• Important to provide continuity of off-carriageway cycle
routes across busy roads
• A crossing is simply a junction where one or more arms
only carries cycle traffic
Signal-controlled
Priority

Cycle Priority Crossings Without Signal Control
• Signing defines who has priority
• Options:
– Road narrowing
– Central islands
– Traffic calming
– Coloured surfacing
– Vertical give way signs
• Cycle route has to be on road
hump to have priority

Cycling Across Zebras
• TfL advice – it is legal for cyclists
to ride across zebras.
• Cyclist have no legal priority over
through traffic, however.
• Need cycle facilities on both
sides for cyclists to ‘land’ on
• “Signing the Way” (2011) – DfT
gave intention to permit trials of
cycle use of zebras

Parallel Zebras

Parallel Zebra

Encouragement of Informal Crossing

Pedestrian crossing of cycle tracks

Signal-controlled Crossings
Toucan crossings Elephants’ footprints at signals

Roundabouts

ROUNDABOUTS

• UK roundabouts rarely
comfortable for cyclists
• Typical designs bad for cycle
safety and comfort
– Multi-lane entries
– Wide circulatories
– Easy, fast exits
– Free flow left turn slips
Yet:
• Dutch practice prefers
roundabouts
• Less stop/start, effort, delay
ROUNDABOUTS

• Reduce speeds on the approaches
• Reduce speeds through the junction
• Reduce number of traffic lanes to one
• Reduce size of junction
• Keep entry and exit radii tight
• Avoid left turn slips
• Provide off-carriageway tracks
• Raise driver awareness of cyclists
Roundabouts – Beneficial Measures

Cycle Traffic and the Strategic Road Network
DMRB Interim Advice Note
• Applies to the strategic road network
but provides useful guidance to other
situations
• Use of the term ‘Cycle Traffic’
highlights the specific design
requirements of cycles as vehicles
• Covers junction design principles,
including roundabouts
• Approved by Highways England,
expected to be published in next few
weeks

Roundabouts in DMRB Interim Advice Note
• Normal roundabouts without off-
carriageway cycle facilities not
permitted
• Options
– Off carriageway tracks with
crossings (incl grade separated)
– Introduce signals with appropriate
facilities
– Change to compact roundabout
(low flows)
– Change to different form of junction

Continental Geometry
• Approaches and exits perpendicular
• Entries and exits ~4 m wide
• Entry and exit radius ~10m
• Entry path curvature <100m
• Diameter 25-35 metres
• Central island 16-25 metres
• Circulating carriageway 5-7 metres
• See Traffic Advisory Leaflet 9/97

Lund, Sweden
25m
35m

Lund, Sweden

Radegund Road, Cambridge

Compact Roundabout
• Included in DMRB TD 16/07
• Similar to Continental, although some differences
• Arguably less cycle friendly as written
• Smaller island diameter

Continental Roundabout in
Wales Active Travel Design Guidance
http://gov.wales/docs/det/publications/141209
-active-travel-design-guidance-en.pdf

Compact Roundabouts in DMRB IAN 195/16
• At low flows/speeds, cyclists can remain on carriageway
• IAN upper limit for on-carriageway cycling – 8,000 vpd
junction throughput
• Above that, off-carriageway tracks mandatory

Cycle Markings on Circulatory – Primary Position

Nantes, France

Implied Roundabout

Annular Cycle Lanes
• Used in Copenhagen/Denmark
• Strong presumption of giving way when crossing
cycle lane/track
• Concerns over left-hook problem with UK driving
behaviour
33m

Fureso, Denmark

York

York Roundabout – 5 years cycle collisions

External Cycle Tracks
• Greater subjective safety if cycling provided for off-carriageway
• Continental/compact geometry makes it easier to provide tracks
• Key question: Provide priority at crossings?
• Use one-way tracks if priority
• Two way tracks with grade-separated, no-priority or signal-controlled
crossings

DMRB IAN – Standards for Roundabout Crossings

Dutch Roundabout Without Priority

Assen, Netherlands

Dutch Roundabout With Priority
41m
54m

Amsterdam

Griffeen Way, Lucan, West Dublin – before

Griffeen Way, Lucan, West Dublin – after

Norwich

Crystal Palace

Signalised Crossings on Roundabouts
• Large delays if need to cross several arms
• 2-way track reduces problem
• Staggered crossings a further problem

Harrow

Croydon

Signalised Roundabouts
• General benefits from signals
• Cross or circumnavigate central island via ped/cycle track
• Can use signalised nodes to ‘bike with traffic’

‘Turbo’ Roundabouts

Determining
capacity and the
scope for change at
signalised junctions

Signal Junction Terms

What is the role of the engineer?

To translate science into society
• Newton’s third law:
For every action there is an equal and opposite reaction
• Centripetal force = MV2/R
• Mass of car = c1500kg (1.5 tonnes)
• Velocity = c11m/s (40kmph)
• Radius of 40m = 4,538Newtons
• Radius of 5m = 36,300Newtons
• The smaller the radius the more force is exerted on vehicle
• So wider radii is more comfortable (or drivers could slow down!)

What is the difference between highway engineers and
traffic engineers?

A highway engineer designs roads for traffic;
a traffic engineer designs traffic for roads
• Highway engineers deal with
space
• Traffic engineers deal with
time
Currency: millimetres Currency: seconds

Therefore, signal terminology is all related to time
• Time for this sequence to run through on each arm
RED RED/AMBER GREEN AMBER
2 seconds 3 seconds

Cycle Time
• Time for the signal sequence to run through
R, R/A, G, A and back to R.
• Time it takes for all movements to happen
• Maximum is usually 120 seconds
• Linsig finds optimised cycle times
• Can vary if signals demand dependent or part
of a connected network

Intergreen
• Time between losing and gaining right of way
• Calculate by looking at time to clear before opposing stream collision
• Distance represented as time
Assume East-West loses right of way.
Intergreen depends on difference AF-
BF (or CH-DH whichever is greater)
<9 metres, I/green=5 secs
10-18 metres, I/green=6 secs
19-27 metres, I/green=7 secs
Minimum intergreen is 5 seconds

Lost Time
• The time when vehicles are not moving in the cycle time on any arm
• The sum of the values of (intergreen minus one second)
• All-round pedestrian stages count as ‘lost time’

Phases
• A specific movement that has a unique signal identification
• Any movement that always goes at the same time
• Can help to think of it as all the possible movements at the start then group
them depending on your method of control
• Usually given letters on a method of control

Stages
• The period in a cycle that gives right of way to one or more traffic
movements
• Non conflicting phases can be grouped into stages. (opposing right turn)
• Usually given numbers
• Phases make stages

Method of Control
• A diagram showing how the junction works
• Made up of phases and stages

Phase Delay
• If 2 or more phases in the same stage have different intergeeens this
causes a delay to non conflicted phases

Green Split
• The amount of green shown for a specific phase out of the total cycle
time

Early Cut-off
• One or more streams are stopped but another continues to the next
stage.
• Usually for right turning vehicles who usually have an opposing
movement to cross

Early Release
• Used for cycle traffic to enable them to clear left turn conflict before
general traffic released

Fixed Time
• Predesigned settings which can alter at different times of the day

Responsive Plan
• Applies the most suitable plan based on real time monitoring from a set
collection of plans

Full Responsive
• Adjusts green times and in the
case of scoot sends an optimised
signal to the controller every
second.

All-red Period
• All arms show red to extend periods between phases for extra
assurance beyond intergreen period.

Blackout
• Clearance time after green man invitation to cross.
• If full pedestrian stage then an all red period can be used to extend
clearance time.
• Total ped stage time for 10m straight across crossing would be 16secs.
• Pedestrian crossing speed estimated at 1.2m/s
• Countdown can help avoid pedestrian confusion over when the
conflicting traffic stream will be released

Headway
• Distance expressed as the time between the front bumper of one
vehicle and that of the next vehicle.
• In free flow: the smaller the headway the larger the capacity.
• High speeds lead to loss in capacity as headway increases (SSD)

Primary and Secondary
• Each stopline has a primary signal 1m away usually on the nearside.
• Secondary signal must be within 50m and 30degress of drivers line of
forward sight.

Passenger Car Unit (pcu)
• Agreed values for modelling but actually depend on many factors such
as length, width, power and mechanics of vehicles. Also flow and layout
characteristics
• Car = 1pcu
• MGV = 1.5pcu
• HGV = 2.3pcu
• Bus = 2pcu
• Motorcycle = 0.4pcu
• Cycle = 0.2pcu

Saturation Flow
• The maximum flow through a junction (at its best)

Capacity
• The maximum discharge over a stopline in a given time.
• The fewer the stages and the longer the cycle time the higher the
capacity

Practical Reserve Capacity
• If a junction has a degree of saturation over 90% then it will not be
efficient.
• PRC shows how close to that value you are.
• If way under then consider layout or timing changes that benefit modes
other than general traffic
• PRC=((0.9-D0S) /DoS)) x 100 = ___%

The Laws of Signal Control*
• Thou shalt not have conflicting movements (unless it’s a right turn then
that’s fine)
• Thou shalt not exceed capacity as this is the definition of gridlock
• Thou shalt minimise the number of stages
• Thou shalt have as short a cycle time as possible
(*cyclists are exempt)

Traffic signal
Methods of Control
that benefit cyclists

Exercise Guidance
• No conflicting streams
• Few stages as possible

Enfield A105 – Mini Holland

Hedge Lane
GreenLanes(S)
Bourne Hill
CV
1 2 3
GreenLanes(N)
General Traffic Phase
Cycle Only Phase
Pedestrian Phase
Phase not called
Early Release for CyclesER
KEY
CV

Lea Bridge Road

Shared Pedestrian-Cycle Stage

What to do if you are over capacity
• Area reassignment (strategic modelling)
• Look at banning turns
• Look at adjusting lane widths and turning radii
• Some movements are more important than others (eg bus routes)
• Up to 10% may be removed from the network if a major public realm
improvement scheme is implemented
• FIND OUT EARLY (not 2 years down the line)

Signalised Junctions

Benefits of Signal-controlled Junctions
• Advantageous for cycle traffic, as they can gain priority in the stream by
moving to the front of the queue
• Cycles are traffic and need to be moved expeditiously
• Ensure cyclists are detected by the loops in whatever position they
usually ride through the junction

INTER-
GREEN
INTER-
GREEN
INTER-
GREEN
GREEN A RED RA
GREEN A RED RA
RED RA GREEN A RED
RED RA GREEN A RED
RED RA GREEN A RED
Signal Phases and Stages
A
B
C
D
E
D
E
C
A
B B

TfL, Design standards for signal schemes
(SQA0064)
Guidance on signal schemes
• Staging an be quite complex
• Designed to maximise traffic flow
through the junction
• Times of stages based on
splitting the optimised cycle time
in proportion to demands on each
approach

Advanced Stop Lines
• Advantages
– Places cycle traffic ahead and in line of
sight of motorised traffic if arriving during
red phase
– Can make right turning easier
– Reduces chance of being squeezed by
left turning motorised traffic
– Prioritises cycle traffic
– Increase junction efficiency

Advanced Stop Lines
• Disadvantages
– Of little value during green stage
– Can encourage cyclists to be in conflict with turning traffic
– Potential effect on intergreens
• Max. 7.5 metres deep without special authorisation in London
• Can be fed by a cycle lane or
gate (TSRGD 2011)
• TSRGD 2015 to allow cyclists
to cross first stop line legally
(so feeder/gate can be omitted)

ASL with Gate Entry

ASL with Central Feeder

Part-width ASL

• Part-width ASLs already in use – likely to gain general authorisation in
TSRGD
• Cyclists will legally be able to cross first stop line
• Integrated early release signals are being trialled
• Possibilities for ASL depths greater than 7.5m?
ASLs – Developments

Left Hooking at Signals

Merging cycle tracks into general traffic lanes

New York – Mixing Zone

Innovations in
Cycle Signal
Design

Innovations in Cycle Signal Design
• Background
• Cycle Specific Signals
• Ways to Mitigate Left Hook
o Hold the Left
o Cycle Gates
o Early Release
• Two Stage Opposed Turns

Background – Cycle Superhighway
Introduced 2010

• Predominantly on carriageway facilities
• Extensive use of Blue Paint

• Some junction redesign
• Mainly removing left-turn slip lanes

Background – Cambridge Heath

Changes in Design
New CSH
routes
TRL Trials
On Street
Trials
Changes in
TSRGD
Continental
Practises
International
Benchmarking
Better
Junctions
CSH
Upgrades

Learning from Others
International Study
• Trip to Paris – March 2013
• Trip to Copenhagen – April 2013
• Trip to Holland – May 2013
International Bench Marking
• Visits to 14 cities during
Summer 2013
• Report published by Urban
Movement for TfL – Dec 2014
https://www.tfl.gov.uk/cdn/static/
cms/documents/international-
cycling-infrastructure-best-
practice-study.pdf

Common Techniques - Junctions
• J1 - Advanced stop-lines
• J2 - Cycle-specific signals
• J3 - Two-stage opposed turns
• J4 - Measures to minimise ‘left hook’
• J5 - Cycle exemptions at red signals
• J6 - Simultaneous greens for cycles
• J7 - Cycle-friendly roundabouts
• J8 - Parallel pedestrian & cycle crossings
International Bench Marking

TRL Trials
Cycle Facility Trials
• Started December 2012 - completed Oct 2013
• 6 Physical Trials constructed
• 2 desk-top studies
• 1 Cycle Simulator build
http://www.trl.co.uk/solutions/sustainability/cycling/safer-cycling-innovations/
• Additional off-street trial - Mar ‘14 – Jul ’14
• On Street Trials

TSRGD2002 “Original” Cycle Signal

• Understanding and Compliance as
“Full Red”
• Stepping stone for LLCS
• Installed at 13 Locations in London
Red Cycle Aspects

Low Level Cycle Signals

LLCS Usages
On its own Repeater Early Start

Hold-the-Left

Kennington Oval CS2 – Cambridge Heath
Hold-the-Left

Hold the Left Video
Hold-the-Left – Cambridge Heath

Queens Circus – Before

Queens Circus – After

QC North to South
Queens Circus – Progression

Cycle Gate

Video
Cycle Gate

Early Release
Cambridge Heath Road – 4 seconds early release for cyclists

TRL 4 seconds
Early Release Video - TRL

Early Release – Estimated Benefits

• All the car drivers and about 95% of cyclists and motorcyclists said they
noticed the early release.
• Over 80% were positive about the early release
• About 75% of cyclists and about 50% of car drivers did not notice the
difference between the shorter and longer early releases
Early Release Findings

Sidney Street - Early Release
Early Release Video - Cambridge Heath

2-Stage Right Turn
A
B
C
D
Single-stage ‘normal’ right turn path
Two-stage right turn path
Adjacent approach
Storage
area or
‘box’

Use of 2-Stage Right Turn

• Original concept was to provide a choice in movements
• Assumed Cyclists mixed in traffic or cycle lane
• What happens with Segregated facilities?
“Mandatory” 2SRT

Cambridge Heath

2SRT
2-Stage Right Turn video - Cambridge Heath

• Case 3820 – 7.5m ASL
• Case 3885 – 250mm Diag 1049 marking
• Case 4079 – Toucan crossing with countdown aspects
• Case 4153 – Part-width ASL
• Case 4209 - 50mm Diag 1004 and 1008 marking
• Case 4214 – 250mm Diag 1010 marking across junctions
• Case 4222 – Reduced size elephant feet
• Case 4260 – 250mm Diag 1009 marking
• Case 4289 - LLCS, HLCS Red cycle aspect, green cycle 200mm aspect,
100mm box signs (NLT, NRT, NUT, AO/TL/TR)
• Case 4312 – “Except in Two Stages” box sign and Two Stage Right Turn
sign
DfT Authorisations

SQA651 – Design of traffic signal control for pedal cycles
Documentation

Separate stages

Cycle Track Entering Junction
• Signals designed in normal way
• Detection of cycle traffic by loops or microwave

Cycle Track Entering Junction

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