Newcastle cdt day 3 as delivered

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

Session 3 Agenda
12:30 Registration
13:00 Modelling
Introduction
Microsimulation & Cycling
Design Revision
14:00 Break
14:10 Making a Balanced Case
Health
Safety
Delay
15:20 Break
15:30 Your Project
16:00 Finish

DESIGNING FOR CYCLING BRIAN DEEGAN + JOHN DALESDESIGNING FOR CYCLING BRIAN DEEGAN + JOHN DALES
MODELLING

Introduction

• A simplified representation of a part of the real world
• Traffic models approximate the movement of goods
vehicles, taxis, buses, cyclists, cars and pedestrians
through the network
• Using our knowledge of the network, we replicate
real-life conditions in our models to test future
scenarios and predict outcomes
What is a Model?

Why do we need models?
• Offline scenario testing, avoids unnecessary disruption on street
• Contingency plans can be developed, that could not otherwise
be tested before the event
• Ensure that we balance the needs of all road users
• Help us to predict the impact of schemes in the future, in
particular a strategic view of the cumulative impact of all
schemes planned to be built
• Enables us to communicate the benefits and impacts of a
scheme to stakeholders and the public

What is Operational Modelling?
• Operational modelling focuses on analysing the predicted impact of the
many large and small changes taking place across London, and helps
to ensure that well informed operational decisions are taken.
• It provides a framework to objectively compare the performance of
scenarios or design options against each other
Strategic Model Output 3D Microsimulation Output

Data Requirements
• Traffic counts (automatic and classified)
• Accurate road information (lanes, capacities, turns, topography)
• Signal timings
• Origin / Destination data – roadside interviews
• Population and employment statistics
• Future year growth estimates
• Information on future schemes/changes in land use
Models are only as good as the information put in

Model Outputs
Results from operational modelling can tell us:
• Journey Times for each mode
• Traffic Signal Strategies
• Predicted Reassignment Effects
• Emissions / Environmental Impacts
• Congestion / Delay / Queue Lengths
/Journey Time Reliability (JTR) etc
• ...and many more!
Operational modelling delivers a network
operating strategy

Hierarchy of Models - Overview

Demand Models
• TfL Group Planning responsible for
producing demand forecasts using
their LTS, HAMs and RailPlan
models
• The demand model produces
origin-destination trip matrices,
segmented by time period and
mode.
• Demand elasticities define how
much the demand will change for a
given change in cost
Trip
Generation
Trip
Distribution
Trip
Assignment
Mode Choice
Costs
Demographic &
employment
data
Network
Demand
elasticities
4 Step Model
Gravity model
parameters

Demand Models
• Transport models calculate
forecasts of trips and cost of travel
given assumptions about the
transport network and travel
demand
• Generalised cost is linear function
used to reflect the overall
perception of difficulty of travel
• The demand and assignment
models depend on each other,
they are run alternatively until they
converge to equilibrium. ie.
changes in demand and cost are
less than a specified tolerance
Trip
Generation
Trip
Distribution
Trip
Assignment
Mode Choice
Costs
Demographic &
employment
data
Network
Demand
elasticities
4 Step Model
Gravity model
parameters

• Highway traffic assignment modelling software used for large
networks
• The model computes routes between all origins and destinations
such that each trip seeks to route along the minimum cost route,
equilibrium assignment
• Scheme assessment: Indicative view of local reassignment effects
• Feasibility study / relative appraisal of options
• Predicted impacts and flow / routing outputs to help inform the
detailed design stage
• Cyclists not historically modelled, research underway to incorporate
Strategic Models - VISUM / SATURN

Inputs Outputs
• Demand matrices, by purpose
• Network supply
- Links; speed limits, capacities
- Junctions; method of control, fixed signal
timings, lanes, permitted movements, etc
• Vehicle routing paths
• Traffic volumes, speeds, queues and
journey times on links
• Scenarios can be compared to give;
- traffic reassignment
- changes in flow, speed and JTs
Strategic Models - VISUM / SATURN

Junction Modelling - Linsig
• Used for the assessment and design of
isolated traffic signal junctions and
small networks
• Cannot model UTC systems, the stage
order and cycle time is a fixed input
when green times are optimised. Does
not account for platooning of traffic
between adjacent junctions
• Cyclists can be represented in the
network in PCUs
• Cannot model the interaction of cyclists
with other vehicles

Inputs Outputs
• Junction layout
• Junction information / geometric details
• Signal information
• Fixed turning flows
- observed in a base year traffic count
- forecast for a future year based on
strategic modelling or global growth factors
• Optimised signal timings
• Measure of Delay (PCUHrs)
• Degree of Saturation (DoS)
• Practical Reserve Capacity (%)
• Queue Lengths (PCUs)
Junction Modelling - Linsig

Junction Modelling - TRANSYT
• Used for the assessment and design of small to medium
sized networks of signalised and priority junctions.
• Cyclists can be represented in the network in PCUs
• Cannot model the interaction of cyclists with other vehicles

Inputs Outputs
• Junction layout
• Junction information / geometric details
• Signal information
• Fixed flow data
• Optimised signal timings
• Measure of Delay (PCUHrs)
• Performance Index ($/Hr)
• Degree of Saturation (DoS)
• Queue Lengths (PCUs)
Junction Modelling - TRANSYT

Junction Modelling - ARCADY
• Assessment of Roundabout Capacity And DelaY, used for the
assessment and design of non-signalised roundabouts.
• For a given set of geometric measurements of an approach
arm, the model determines entry capacity as a linear function
of circulating flow
• Cannot model the interaction of cyclists with other vehicles,
cyclists typically included within the PCU flows
• Pedestrian demand at crossings on the entry and exit arms
can be represented

Inputs Outputs
• Roundabout type
• Roundabout information / detailed geometric
measurements
• Fixed traffic and pedestrian flow data
• Measure of Delay (veh. min)
• Ratio of Flow to Capacity
• Queue Lengths (Veh)
• Accident Risk
Junction Modelling - ARCADY

Microsimulation Modelling - VISSIM
• Microsimulation traffic modelling tool developed to model urban
networks controlled predominately by traffic lights.
• Simulates motorised private transport, goods vehicles, public transport,
pedestrians and cyclists
• Displays all road users and their interactions in one model.
• Used to assess over-saturated conditions, exit blocking, accidents,
vehicles platooning, shock waves, bus priority schemes, exhaust
emissions, etc.
• Can be used to create detailed computational results or 3D animations
for different scenarios.

Pedestrian Modelling LEGION / VISWALK
• Microsimulation modelling tools
developed to simulate the movement
of pedestrians through urban
environments
• Takes into account how individuals
interact with each other and with the
physical obstacles in their environment.
• Can perform virtual experiments on the
design and operation of a site and
assess the impact of different levels of
pedestrian demand
• Can produce simulations, maps,
graphs, videos and 3D animations
• Outputs include pedestrian journey
times and Fruin’s Level of Service

Modelling Case Studies

Two-way segregated cycle
track resulting in a
reduction in lanes available
to general traffic along most
of the proposed route
• Redesigned junctions
• Banned turns at various locations
• Changes to bus and coach stops
• Changes to footways and pedestrian crossings
East-West Cycle Superhighway

Junction Modelling CountsOn-site observations
(saturation flow, flare usage)
Traffic signal
plans
Demand
dependent
stages?
LINSIG
TRANSYT
Can you improve PRC/delay to make junction more efficient?

Strategic Modelling
Validated Base
model
Proposed signal timings
Proposed designs
Outputs for VISSIM
High level performance
Can analyse multi-scheme impact

Microsimulation Modelling
Signal timings
Road layout
Base/Future demand
across all UCs
Routing information
Background map
Driver behaviour
Pedestrian data
Journey times for different vehicle types
Saturation flow across new stoplines
Vehicle speeds, acceleration
Many potential outputs including:
Queuing

Strategic Model
Junction Model
Microsimulation Model
Optimised
signal
timings
General
Traffic
Routing and
Flow
Information
General
Traffic Flows
Capacities
and Signal
Timings
Relationship Between Models

Microsimulation & Cycling

Distinguishing features of a microsimulation are:
• Individual vehicles are modelled – e.g. cars, bikes, lorries, buses.
• Vehicles interact with each other and their environment e.g. car
following, signals, stop lines, overtaking, give way.
• Vehicles have driver behaviour characteristics – e.g. Aggression,
desired speeds, acceleration profiles.
• Stochastic, random behaviour – seed values
• Time steps – ‘second by second’ simulation
• Animation – vehicles and network can be viewed during simulation.
Visual interaction between the user and the software.
Microsimulation

Microsimulation Vs Conventional Simulations
TRANSYT

VISSIM

BIG DATA
VISSIM

• Developed to model urban networks controlled predominately by traffic
lights.
• Signal control is an extremely strong aspect in so much that any existing
or proposed form of control strategy can be simulated.
• It is particularly good at simulating the interaction between general traffic
and on-street public transport.
• VISSIM was developed by the University of Karlsruhe (Germany) in the
1970s.
• Since 1993 VISSIM has been continuously updated and marketed by
PTV consultants (Karlsruhe). Current release is version 8.
• VISSIM is used by organisations world-wide.
Microsimulation - VISSIM
VISSIM is a microscopic simulation tool developed in Germany by PTV.
VISSIM is short for “Verkehr In Städten – SIMulationsmodell” which
translates to “Traffic in Cities – Simulator”

Essential data needed:
• Network layout (geometry),
• Flows and turning proportions,
• Traffic flow compositions,
• Bus frequencies, Dwell times,
• Bus stop locations,
• Signal timings and controller logic,
• Data for model validation: saturation flows, journey times, queue
lengths.
Also may need, depending on the purpose of the model:
• Speed and acceleration profiles,
• Origin/Destination matrices,
• Bus boarding & alighting numbers,
• Pedestrian flows,
• Bus occupancies,
• Various different inputs based on the required model outputs…
Microsimulation - Inputs

The physical networks within VISSIM models are constructed using links
(blue) & connectors (pink). Connectors act just as links do but provide
connections between links on a lane by lane basis and subsequently define
routes, turns and queuing behaviour.
Links/Connectors are NOT bi-directional and are strictly lane based. This
can mean schemes involving ‘shared spaces’ are extremely, if not
impossible, to model directly.
Links/Connectors can also be restricted to be used by a certain mode(s)

How does microsimulation work?
• Based on extensive field tests
• Driver Behaviour models:
– Car following
– Lane changing
– Lateral behaviour
– Gap acceptance
– and several more sub-models.
• Formulate driver psychology
– Driver aggression
– Driver awareness
– Reaction to surrounding elements
(signals, adjacent cars, etc…)

VISSIM - Cyclists
All vehicles are modelled & can be grouped in a number of ways depending
on their size, performance, purpose or applicability to highway regulations.

• The core behaviour model in Vissim is the ‘car following’ model
which is not as well suited for cyclists as it is for other modes.
• Fortunately the ‘car following’ model can be adjusted to minimise its
influence on cyclists, though not completely, and the calibration effort
can be focused on the ‘lateral behaviour’ model.
• Without this intervention cyclists are treated in precisely the same
way cars (etc.) are treated when considering safety distances,
queuing behaviour, longitudinal speeds and direction changes.
• Modelling team experience of theses difficulties has led to two
distinct ways of calibrating and validating models and interpreting
modelling results where a significant number of cyclists are involved.
VISSIM - Cyclists

• Our Team spent many hours observing the few segregated signalised
cycle lanes in London with sufficient volumes to create queues during the
red signal period.
• Our aim was to identify relationships between cycle lane width, queuing
behaviour and consequently rates of discharge.
R² = 0.9008
0
2
4
6
8
10
12
14
16
0 5 10 15
Time(s)
Number of Cyclists
Cannon St Rd
Linear (Cannon St
Rd)
Single file queue discharge
At 1m width or less a single
queue of cyclists will form.
VISSIM – Segregated Cyclists
NB This study is ongoing and values presented are likely to be refined as more data is collected

0
1
2
3
4
5
6
7
8
9
10
1 1.5 2 2.5 3
Frequency
Width (m)
1 Queue
2 Queues
3 Queues
Lane width determines the number of queues formed and thus the resulting
discharge rate. This is the basis of our calibration target in Vissim.
• Cycle lane width has an impact
on cyclist discharge rate.
• On narrower lanes of around 1m,
where cyclists are forced into one
queue, the rate measured is just
under one cyclist per second,
with an average saturation flow
of 3349 cyclists per hour.
• Somewhere between 1m and 2m
it becomes possible for cyclists to
form more than one queue.
During observations this extra
capacity was rarely fully utilised
as a second lane.
0
2
4
6
8
10
12
14
16
0 5 10 15
Time(s)
Number of Cyclists
Dock Street EB
Dock Street WB
Cannon St Rd
Linear (Dock Street
EB)
Linear (Dock Street
WB)
Linear (Cannon St
Rd)
VISSIM – Segregated Cyclists
NB This study is ongoing and values presented are likely to be refined as more data is collected

Cyclists’ Clearance Requirements
Width of cycle (static)
0.75m
Deviation from straight line in motion
0.75m + 0.25m = 1m
 a cyclist in motion has a “dynamic envelope” 1m wide
Deviation from straight line at low speed (wobbling) or on rough
surface (avoiding gullies or potholes)
0.75m + 0.75m = 1.5m
 extra width needed up hills and at junctions, smooth surface
Offset clearances from kerbs (measured to wheel)
0.25m: kerb <50mm (within dynamic envelope)
0.50m: kerb >50mm (within dynamic envelope)
0.75m: occasional feature, e.g. sign post, lamp column
1.00m: continuous feature, e.g. wall, railing, parapet

VISSIM Cycle Behaviours
• Segregated Link
• Segregated Stopline
• Mixed Link
• Mixed Stopline

Key Findings TRL Study
• Cyclists faster than modelled. Approximate mean max speed 30km/hr.
• Overtaking occurs mainly on links not at the junctions
• Speed varies during the day. AM Peak highest
• Cycle hire bike behaviour different to commuter bike

Calibration
Car following behaviour

Calibration
Lateral behaviour

Continuous Improvements

VISSIM Outputs 3D
3D pictures of the network for clients and the general public

High Resolution videos driving project excellence
VISSIM Outputs 3D

Future Developments
• Improving cycle behaviour algorithm in mixed traffic and
segregated conditions
• Software providers cycling behaviour algorithm
• Bicycle scoot in UTC-VISSIM offline modelling
• Discharge behaviour depending on the geometry
• Modelling various cyclist groups (commuters, leisure,
aggressive, passive, etc)
• Cloud modelling

Bicycle SCOOT

Design Revisions

Strategic Modelling

Lea Bridge Road Timeline
Sep 14 Dec 14 Jan 15 Mar 15
May 15 Oct 16

What MOC would you choose if over 100% DOS?
Enfield (120% DOS)

What would you change about the MOC?

MAKING A BALANCED CASE

Health

The BIG 4
Nutrition
Lack of
activity
Alcohol
Smoking

• 150 minutes of physical activity each
week reduces your risk of getting many
of the most serious long term conditions
• 4 in 10 Londoners do not get the
minimum physical activity each week
that they need
• 1 in 3 Londoners don’t get even 30
minutes of activity each week
• The easiest way to stay active
through life is walking & cycling as
part of daily routine
• The main way that people in London
stay active is through walking (and
some cycling)
Why is physical activity so important?

DESIGNING FOR CYCLING BRIAN DEEGAN + JOHN DALESSource: CMO Report 2011
How do we make the biggest difference?
We get much larger health benefits
from lots of people doing a little bit
more exercise than a few people
doing lots more exercise.

Street environments & transport are central to the
health of Londoners
The health impacts of the transport system in London
relate mostly to motorised road transport

Outcome to be monetised
Risk of
death
Illness
Healthcare
costs
Productivity
Healthmeasure
Physical Activity HEAT SART
Air Quality
Road Traffic
Collisions
Noise
Severance
Which health measures can we easily monetise?
The impact of
physical activity on
illness and
healthcare costs
are the next areas
that are likely to be
monetised

How do we describe the impacts of transport schemes
on health?

 A World Health Organisation
tool for monetising the
health benefits of walking
and cycling, due to
increased physical activity
levels.
What is HEAT?

• Inform policy making by capturing health benefits of plans &
proposals.
• Strengthen business cases, especially schemes where road space is
reallocated away from motor vehicles.
• Allow the health benefits of walking /cycling to be included in economic
decision making.
• Health is one of TfL’s strategic priorities and HEAT can be used to
assess our progress.
Why use it?

Levels of
walking and
cycling
£ health
benefits of
walking and
cycling
How does it work?

ProspectiveRetrospective
How can it be used?
Benefit right now
Valuation of the
health benefits of
increased walking
or cycling after a
project.
Valuation of the
health benefits of
all walking or
cycling in an
area right now
Valuation of
predicted health
benefits of
planned projects

ProspectiveRetrospective
How can it be used?
Benefit right now

2 key pieces of data:
• Roadside counts
• Population surveys
• Modelling/estimates
• Route user surveys
• Modelling/estimates
What information do you need?
Number of
people cycling /
walking
Average amount
of TIME spent
cycling / walking
per person
* HEAT calculates time spent cycling and walking
based on average speeds of 14km/hour and
4.8km/hour. Therefore you can enter distance cycled
or walked and the tool calculates time from this data.

HEAT Case Study:
Royal College Street, Camden

Royal College Street

Before
• Segregated cycle track clashes with side roads

After
• Cycle track on both sides
• Armadillos
• Planters as lane markers
• Resurfaced road
• Street trees
• Repaved pavements

1. Cycling data obtained before and after:
• Trip counts – manual and automatic loop
2. Cost of the scheme = £475,000
Why use HEAT?
We want to assess the value for money delivered by the scheme
What data do we have?

2012 baseline
Northbound = 499 per day
Southbound = 325 per day
Total: 824 trips per day
What were the results?
2015 counts
Northbound = 1000 per day
Southbound = 700 per day
Total: 1700 trips per day

Deaths per year prevented
“The number of
deaths per year
that are
prevented by
this change in
cycling is: 0.11”

Monetised value of deaths prevented
“The current value
of the total benefits
accumulated over
10 years is:
£2,199,000”
“The average annual benefit, averaged over 10
years is: £220,000”
“The number of
deaths per year
that are prevented
by this change in
cycling is: 0.11”

£2,199,000
£475,000
= 4.6 : 1
How do we use the HEAT output?
Monetised benefit from
deaths prevented
Calculate a BCR (benefit:cost ratio)
Cost of scheme
If you add in the benefits from walking you can improve this ratio

Clapham Old Town

Baseline
5446 trips per day
1304 trips per day
Estimated uplift
6263 trips per day
1500 trips per day
15%
15%
Clapham Old Town

Annual Health Benefit
£375,000
£49,000
Clapham Old Town

Aldgate Gyratory

Baseline
31,510 trips per day
Estimated uplift
36,237 trips per day15%
Aldgate Gyratory

£2,167,000
Aldgate Gyratory

Leonard Circus

Baseline
2,140 trips per day
Estimated/observed uplift
3,038 trips per day42%
15%
Leonard Circus

£1,762,000
£225,000
Leonard Circus

Holborn Circus

Baseline
Estimated uplift
49,450 per day
15%
Holborn Circus

£2,959,000
Holborn Circus

True or False – can HEAT tell me?
 Illness costs prevented by physical activity
 Number of deaths prevented by people switching from car to
walking
 Projected uplift in cycling from my scheme
 Health benefits of walking from a cycle scheme
 Snapshot of the health benefits of current London walking levels
 Projected uplift in cycling from my scheme
 Illness costs prevented by physical activity
 Current levels of walking and cycling in my area Current levels of walking and cycling in my area

Cyclists
Non-
cyclists
Study begins Study ends
follow up
over time
Dead
Alive
Dead
Alive
select study population
(all healthy at start)
measure outcome
Introducing cohort studies

% dead
% dead
Relative risk = ratio of the risk of death in cyclists compared to
risk of death in non-cyclists
% of cyclists who died
% of non-cyclists who died
=
Cyclists
Non-
cyclists
Dead
Alive
Dead
Alive

9 deaths / 10,000 cyclists
10 deaths / non-cyclists
Cyclists
Non-
cyclists
Dead
Alive
Dead
Alive

Determined from studies of what people would be willing to
pay for small reductions in risk of death in a population
Value of statistical life
 The value of statistical life is the monetary value given to a
death by statisticians
Enables us to value the deaths we prevent in £

Guidance

Safety

The importance of road safety globally

How do we compare?
0
20
40
60
80
100
120
Ratepermillionpopulation
Road deaths per million population: 2013 and 2014 (provisional)
2013
2014

110
Pedestrians, cyclists and motorcyclists at highest risk
in London
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
2000 2005-9 2014
KilledorSeriouslyInjuredCasualties
Other vehicle occupants
Bus or coach occupants
Car occupants
Powered two-wheeler
Pedal cyclists
Pedestrians
• 127 people killed in 2014
• 2,040 seriously injured

111
Pedestrians, cyclists and motorcyclists at highest risk
in London
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
2000 2005-9 2014
KilledorSeriouslyInjured
Casualties
Car occupants
Powered two-wheeler
Pedal cyclists
Pedestrians
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
2000 2005-9 2014
KilledorSeriouslyInjuredCasualties
Car occupants
Powered two-wheeler
Pedal cyclists
Pedestrians
Vulnerable Road User %
(Right axis)
• 127 people killed in 2014
• 2,040 seriously injured

112
Risk by mode in 2009

113
Casualty Definitions
Fatal collision: At least one person is killed.
Serious injury: An injury for which a person is detained in hospital as an “in-patient”,
or any of the following injuries whether or not they are detained in hospital: fractures,
concussion, internal injuries, crushings, burns (excluding friction burns), severe cuts,
severe general shock requiring medical treatment and injuries causing death 30 or
more days after the accident.

Department for Transport statistics
https://www.gov.uk/government/publications/reported-road-casualties-great-britain-annual-report-2014
RAS60001
Average value of prevention1
per reported casualty and per reported road accident2
:
GB 2014
£2014
Accident/casualty type Cost per casualty Cost per accident
Fatal 1,836,054 2,066,732
Serious 206,321 235,791
Slight 15,905 24,887
Average for all severities 54,849 77,825
Damage only - 2,204
1 The costs were based on 2014 prices and values
Value of Prevention
114
• Rule of thumb Fatal £2m, Serious £200k, Slight £20k i.e., ratio 100:10:1
• About 1% of UK GDP in 2014
1,836,054 2,066,732
206,321 235,791
54,849 77,825 2,204
15,905 24,887

Working together, towards roads free from death & serious injury
A Safe System to minimising road danger
Principles of a safe system
1. People make mistakes
2. There are physical limits to what the human
body can tolerate
3. All those with a role in designing, building,
operating, managing and using the road network
have a responsibility to improve safety

116
Driver error contributes to most
collisions.
Five key sources of danger identified
for London
1. Travelling too fast
2. Becoming distracted
3. Risky manoeuvres
4. Drink/Drug use whilst driving
5. Failure to comply with the laws of
the road
We can try and change these
behaviours BUT human behaviour will
fail
Safe people: Sources of Road Danger
Collisions with a Sources of
Danger contributory factor
(85%)
Without
(15%)

Speed is key
• It is estimated that each 1mph
reduction in speed reduces the
frequency of all severities of
collision by around 6%.
• If a vehicle travelling at 40mph
hits a pedestrian or cyclist there
is only a 15% chance of
survival. At 20mph however, the
chance of survival jumps to
95%.

118
Pedal cyclist KSIs per billion km cycled

Exercise: Collision Diagrams
Royal College Street, Camden

Collision Diagrams

122
Royal College Street: Case Study
Pre 2003
• One way A road
• 3 northbound lanes
• Residential and commercial
parking
• No traffic calming
2003 to 2013
• One way A road
• 2 northbound lanes
• Two-way cycle track on western
side of carriageway
• Speed cushions

Stats 19
• Covers 1979 to present
• 200,000 records a year
• Covers accident type, vehicles involved and casualties

Stats 19

Royal College Street
North
Georgiana Street
Pratt Street
Plender Street
Pancras Road
One way
general
traffic
Two way cycle
track on
western side of
carriageway

Next Steps
• Look for patterns in:
– Type of user
– Road conditions
– Seasonality
– Time of day
• Investigate possible causes through on site inspection.
• Is mitigation possible?
• Beware: No solution is perfect. Each has its risks to users.

Patterns
• Lots of cyclists
• Clusters at side roads
• Lots of hooks
• Cyclists heading south in serious
collisions
• Above average for road of this
type
• What in highway layout could be
causing collisions?

Accident remedial measures

Effect on
collisions = 0
Accident remedial measures

133
Visualisation of planned scheme

Forecast collision savings
serious slight
Accidents saved/annum 1 1
Cost per accident £178,160 £13,740
Total amount saved £178,160 £13,740
Total collision savings £191,900
Cost of scheme £160,000
First year rate of return 120%
• Predict how many collisions you will save based on
how well you met your safety objectives
• Nothing is perfect so compare to average road types
and junctions in your area

Value of Life

Risk
Compare collisions on your
scheme with the borough
average on the same road

• How many by road
type
• Also zebras,
roundabouts, pelicans
• RCS = 6 per km

How many collisions would you expect in your area at ATS?
RCS=
1.3

How many cycling collisions would you expect?
RCS= 4per km
Conclusion: something is causing the street to perform badly, so can this
cause be identified and removed?

140
Removal of bi-directional track reduced potential
for 7 of the collisions

141
(c) Alex Sully
Bus stop boarders creating effective shared space during
alighting/departing period. 0 collisions saved but subjective
safety issues.

142
Social cycling and enabled overtaking attracting increased
cycle flows which might mean more collisions
(c) Voleospeed

Elephant’s footprints providing clarity at junction
potential to save 2 collisions
143
(c) GB Cycling Embassy

Collision savings 1st year
£334,277
2 slights 0 serious from
2010 – 2012 average of 4.3 slights and 1.3 serious per year
So 2.3 x £23,136 + 1.3 x £216,203 = £334,277

Delay

We all know congestion when we see it
‘Traffic congestion is a condition on road networks that
occurs as use increases, and is characterized by slower
speeds, longer trip times, and increased vehicular queueing.’
(Wikipedia)

How do we measure congestion?
• Comes in two forms:
– Recurrent
• Responsible for the majority (possibly as high as 75%)
– Non-recurrent
• Journey times
• Delay
– Usually defined as the difference with free-flow (overnight) speeds
– Established methods for valuing
• Journey time reliability
– Key TfL metric, but much harder to value

0
20 25 30 35 40
%ofjourneys
Journey time distribution
The measure is defined as: ‘The Percentage of nominal 30 minute average
length journeys completed within 5 minutes of this time’
Average journey length
5 minute
Allowable
variation
Cut off for an
‘acceptable’
average journey
% of
‘acceptable’
journeys
TfL’s JTR metric

But there’s more!
• Pollution/emissions
– Also hard to value
– However could account for an additional 25% disbenfit on top of
delays
• For buses
– Excess wait time
– Running time variability
• Additional bus and freight operating costs
– Maintaining larger fleets
• Revenue loss
– Passenger numbers affected by congestion

Why does congestion matter?
• The size of the problem
• Targets
• Interdependencies
• ‘Politics’

The size of the problem
Safety
Health
Congestion£1.2 billion per annum
(zero injuries)
Health
Congestion
£4.2 billion per annum
(all 4.3m potential cycle trips daily)
£4.2 billion per annum
(free flow conditions,
delay only)

Interdependencies
Safety
Health
Congestion
Collisions cause congestion
Reverse relationship unclear
Congestion leads to air pollution
(a substantial disbenefit)
Swapping cars for cycling will reduce
congestion
Swapping the bus for cycling and cycling
infrastructure will increase it
More cycling may lead
to more casualties
Less casualties will lead
to more cycling

Journey time (mins)
Time of day00:00 24:00
30
40
Incident duration = 3 hours
Average additional delay = 10 mins
Calculating average incident delay

Average hourly flow = 1000 vehicles
x
x
Total vehicle hours of delay = 500
=
Calculating incident incident delay

Working Commuting Other
3%
Trip
purpose
£30Average
value of time
20% 77%
x
£7£8
(from willingness
to pay surveys)
Average occupant value of time = £8 per hour
Average value of time per person

1.2
18
1.3 1.5
Average
occupancy
10% 70%
3%
17%Average
mode mix
x
x
Value
of time
£8 £8 £16£16
Average vehicle value of time = £18 per hour
Vehicle composition

Average hourly flow = 1000 vehicles
x
x
Total vehicle hours of delay = 500
=
x
Average vehicle value of time
(£18 per hour)
= £9,000
Calculating total delay

Uplifted man-hole cover meant two lanes had to be shut.
Event location
A40 Western Avenue, Sunday 31st August 2008

Journey times rapidly increased by half an hour following
incident
Cover
reported
uplifted
Based on a daily
flow of 105,000
both directions and
monetary value of
£17 / hour / vehicle
Total cost:
£64,000
A40 Western Avenue, Sunday 31st August 2008

0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
AM
Inter
PM
AM
Inter
PM
AM
Inter
PM
AM
Inter
PM
AM
Inter
PM
West North E ast S outh C entral
Minsperkm
P rev 3 Thus S trike Wed 5th F eb S trike Thu 6th F eb
0.0
2.0
4.0
6.0
8.0
10.0
00:00
01:00
02:00
03:00
04:00
05:00
06:00
07:00
08:00
09:00
10:00
11:00
12:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Minsperkm
P rev 3 Thus S trike Wed 5th F eb S trike Thu 6th F eb
Area
Delay (veh.
hours) Cost of delay
% change vs
05/02/2014
West 12,882 £218,996 +3%
North 20,329 £345,588 -6%
East 21,175 £359,967 +1%
South 5,857 £99,562 -26%
Central 40,654 £691,121 +4%
Total 100,896 £1,715,234 -1%
Prev day 99,845 £1,697,367 n/a
Central London
Overall impact on observed road network
(estimated to be about half of total road impact)
Outer
Inner
Green = Journey time <= Profile time x 0.8
Yellow = Journey time > Profile time x 0.8
Amber = Journey time > Profile time x 1.2
Red = Journey time > Profile time x 1.5
Black = Journey time > Profile time x 2
Tube strike analysis

Reliable roads

Quality bus network

Reduced casualties

More and safer cycling

Speed contravention levels

Calculation
• 30 second delay
• AADF 10,974
• Car VOT = 8.37
• Annualisation factor from daily flow 340
• Annualisation factor from am peak 1900
• Delay x (Car VOT/3600) x Traffic Volume x Annualisation factor =

Delay cost per year
£260,248

Achieving Balance

Mayor’s Transport Strategy
• As always, there are trade-offs
which means a balanced
approach must be taken.
• London’s transport network is
finite and there is often
competition for this limited space

Royal College Street balance
-£300,000
-£200,000
-£100,000
£0
£100,000
£200,000
£300,000
£400,000
Health Safety Delay

Justification for delay imbalance
• General traffic exceeding the speed limit so drop of 5mph meant
theoretical delay
• 45% of traffic reassigned away from Royal College Street
• Attempt to make a key cycling network route through a town centre
• Parallel red route with spare capacity
• FYRR=74%

Clapham Old Town balance
£0
£50,000
£100,000
£150,000
£200,000
£250,000
£300,000
£350,000
£400,000
£450,000
Health Safety Delay

Just plain good
• Health benefits help justify high scheme costs of £3.5m
• FYRR=24%

Aldgate High Street balance
-£500,000
£0
£500,000
£1,000,000
£1,500,000
£2,000,000
£2,500,000
Health Safety Delay

Mitigating delay
• Delay for general traffic but journey time benefit of £159,446 for buses
• Health benefits justify public realm costs of £17m
• FYRR=15%

Leonard Circus balance
-£500,000
£0
£500,000
£1,000,000
£1,500,000
£2,000,000
£2,500,000
Health Safety Delay

A healthy street
• Scheme would have no business case with health benefits
• Justify expenditure in first year alone £350k spend for £2m annual
benefit
• Back streets with no collision records can be strategically import places
for pedestrians and cyclists
• FYRR= 561%

Holborn Circus balance
-£500,000
£0
£500,000
£1,000,000
£1,500,000
£2,000,000
£2,500,000
£3,000,000
£3,500,000
Health Safety Delay

Creating a place
• Health benefits justify scheme expenditure in first year
• Yearly benefits of £3,438,794 for £3,261,000 investment
• FYRR=105%

Balance issues
• The cumulative effect of delay
• Where there is congestion and buses JTR is king so you need to
improve or stabilise
• Cherry picking the category that benefits your scheme and neglecting
obvious disbenefits in others is unethical practice
• Health and Safety benefits should never be negative if we want better
streets but they often are

Conclusions
• Quantifying health supports all public realm enhancement and cycling
schemes
• Sometimes safety is not an issue but something still needs to be done
to entice people to walk and cycle
• Only do journey time analysis if you have congestion or high flows
otherwise results can be skewed

Conclusions

YOUR PROJECT

Choosing a site
• 400m in length
• At least one signalised junction
• Choose something challenging (you will learn more)
• Don’t think of a solution before you have assessed it thoroughly
• It can be a project you are working on
• It can be in a different borough

Assessing existing conditions
• Site visits should be taken during peak conditions (AM usually)
• Signal assessment will take 30mins to 1 hour
• Traffic counts should be for at least 15mins
• Observations and photos are crucial
• Pick up key information for the level of service (next session)
• What does the street feel like?
• How are people crossing the road?
• Are drivers being aggressive?
• Do people look confused?
• Is it well kept?
• What are the people like?
• How are people choosing to travel?
• Are cyclists behaving aggressively?
• What is the potential for conflict?

Gathering data
• Traffic counts for all modes in all directions at your chosen signal
junction (on site 15minute count, x4 for hourly count x10 for
approximation of AADTF)
• Signal timings ( from on site observation or timing sheets)
• Pedestrian counts (pen and paper, tally in 5’s or 10’s if busy)
• Pedestrian comfort (pedestrians per metre per minute)
• Collision data 3 years within 50m buffer of your link and junction (London
Collision Map)
• Traffic speed data (set a distance get a stopwatch)
• Air Quality (clean air London website or app)
• Noise (generated from traffic data)
• Degree of saturation (pen, paper and stopwatch)
• Gradient (smartphone and calculator)
• All the data you need is either easy to get on site or freely available

Plan view of signalised junction
• Clearly show new kerb lines, old kerb lines and infill (tip: its generally
easier going out into carriageway than in to the footway because of
services)
• Clearly show existing parking and relocated parking (tip: only a few
people ever get to remove parking so reposition it)
• Show final line markings
• Text boxes and arrows should be used to reference any change to the
existing layout (if something is moved say how much in metres)

Key layout points
• Need to find space for a primary and secondary signal post (tip: if more
than 2 lanes a splitter island is recommended)
• Show pedestrian signal direction (can be far side or near side)
• Every stop line needs a closely associated signal
• Pedestrian crossings need studs and L shaped tactile paving

Key dimensions
• ASL minimum 5m maximum 7.5m
• Gates 18m between stop lines
• 450mm clearance for any vertical object (post, sign, bollard etc)
• Lane widths vary from c2.4m to c5m. Standard UK lane width 3.65m
(12feet)
• Crossing width 4m min
• Studs to stop line distance = 3m
• Can be 1.7m if ASL present
• Island with post min width=1.3m
• If cyclists on one side min= 1m
• Side mounted 1.6m

Writing Style
• Feasibility study
• Assess existing condition
• Come up with options
• Assess impact
• What does your street need?
• What impact will this have?
• You decide the layout
• Cover all elements from course
• Evidence is better than opinion
• BE
• Accurate
• Concise
• Clear
• Well Structured

• 3rd person, present tense
• Reference any statement
• If you state your opinion make sure it is based on site observation and
not assumption
• Every decision has a positive and negative impact. Make the case for
the positive and mitigate for the negative.
• Make a balanced case for your scheme
• Design an option that meets your objectives
• Estimate your option cost
• Make a business case for it based on health impact, collision savings and
potential journey time savings
• Come up with a funding strategy
• Justify the expenditure!
Writing Style

“There is a risk of collision from alongside involving cyclists and
general traffic on the northbound approach to the junction of
Marlborough Road and Constantine Hill. This is due to the
pinch point caused by the pedestrian island which narrows
the carriageway to 3.4m”
“I feel cyclists are in danger of being hit by lorries as the
situation is unsafe. Lorries came over the crest of the hill not
looking out for anybody.”
Writing Style

Presenting Evidence

Contents
Executive Summary
1. Background 5
1.1 Policy Context 5
1.2 Design Objectives 5
1.3 Existing Site Details 7
1.4 Existing Parking Conditions 17
1.5 Existing Site Constraints 17
1.6 Sub Regional Perspective 17
1.7 Place Shaping 17
2. Collision Data and Analysis 18
2.1 Collision Data 18
2.2 Analysis of Collisions 18
3. Traffic Data and Analysis 29
3.1 Traffic Survey 29
3.2 Traffic Data and Analysis 30
4. Site Observations 37
4.1 Site visit 30
3.2 PERS audit 30
5. Statistical Tests37
6. Summary of Safety Problems 37
7. Options for Treatment 38
7.1 Option 1 39
7.2 Option 2 39
7.2 Option 3 39
8. Estimated Accident Savings 40
8.1 Option 1 40
8.2 Option 2 40
8.2 Option 3 40
9. Estimated cost of scheme 42
9.1 Option 1 43
9.2 Option 2 43
8.2 Option 3 40
10. First Year Rate of Return 44
11. Recommended Scheme 45

Suggested Structure
1. Context – Location, geography, street type, link profile
2. Outcomes – Policy context (local), key scheme objectives
3. Existing condition – On site observations, junction type, signal operation,
observed conflicts, interaction with other modes
4. Data and analysis – collision record and patterns, traffic flow, degree of
saturation, signal timing, CloS and JAT
5. Option sketch – Plan drawing of junction, isometric sketch of link
6. Option costs – quick estimation of main elements, highlight funding
7. Business case – balance health, safety and congestion
8. First year rate of return
(estimated report length 10 pages)

Newcastle cdt day 3 as delivered

Recommended

Recommended

More Related Content

What's hot

What's hot (6)

Similar to Newcastle cdt day 3 as delivered

Similar to Newcastle cdt day 3 as delivered (20)

More from Northumbria University

More from Northumbria University (20)

Recently uploaded

Recently uploaded (20)

Newcastle cdt day 3 as delivered