Presentation by Clare Linton at UTSG January 2015. www.city.ac.uk/utsg-2015/programme www.engineering.leeds.ac.uk/dtc-low-carbon-technologies/student-profiles/ClareLinton.shtml

1. DTC Low Carbon Technologies
FACULTY OF ENGINEERING
Developing a methodology to
quantify emissions associated with
excess capacity in urban transport
systems
Clare Linton, pmcli@leeds.ac.uk
Dr. Susan Grant-Muller
Prof. William Gale

2. Overview
• Background and context
Defining capacity
The case study area - Greater Manchester
• Approach
Socio-technical system and capacity
• Developing a framework to quantify capacity and emissions
• Future work, Summary and Conclusions
Background Approach Framework Conclusions

3. Background and context
• Urban transport
dominated by private car
travel and flow is
concentrated into peaks
• Average UK car
occupancy is 1.6
persons
• Collaborative consumption uses resources more
sustainably and could help utilise excess transport
capacity
Data from (Department for Transport, 2012)
Background Approach Framework Conclusions
0
200
400
600
800
1000
1200
1400
1600
1800
Numberofvehicles
Vehicle Mix A34 Manchester (both directions, weekday)
HGV
LGV
Buses/Coaches
Cars
Motorcylces
Pedal Cycles

4. Defining Capacity
• This work defines capacity as the space within the transport
system through which transport demand can be met
• This refers to physical space, both within vehicles and the
roadspace, which can facilitate mobility.
• There are also elements of temporal capacity, with periods
of high and low loading
Background Approach Framework Conclusions

5. Research Questions
1. How much excess capacity is there within the urban
transport system?
2. What is the potential for enhanced use of excess capacity
to deliver emission reductions?
3. How can the principles of collaborative consumption be
applied to examine excess capacity in the urban transport
system?
Background Approach Framework Conclusions

6. Greater Manchester
• Greater Manchester is the
case study area
Large metropolitan county in
NW England
Covers 1276km2
2.6 million residents
10 local authorities
• The framework is applicable
to other urban areas in the
UK and beyond
Background Approach Framework Conclusions

7. Approach
• Socio-technical systems
capture the range of
technological and socio-
economic factors involved
in a complex system such
as transport
• This figure shows the
factors involved in urban
transport capacity
Socio-technical configuration for urban transport
capacity (adapted from (Geels, 2002))
Background Approach Framework Conclusions

8. • This figure shows the
elements that are captured
in the current framework
presented here (those
excluded are in greyed
italics)
• Additional factors are
incorporated in future work
and others are included as
exogenous factors
Socio-technical system and
capacity
Socio-technical configuration for urban transport
capacity (adapted from (Geels, 2002))
Background Approach Framework Conclusions

9. The framework
• The following section presents the framework for
quantifying excess capacity in urban transport systems and
the potential emission reductions.
• This is done mainly through the presentation of a flow chart
and more detail about the inputs, processes and outputs
Background Approach Framework Conclusions

10. Flow chart of framework

11. Flow chart of framework

12. Inputs to the framework
• Survey
500 residents of Greater Manchester
Questions include information about journeys in last 7 days, mode,
journey purpose, time of day and occupancy rates
Survey conducted by Accent MR
• Fleet Data
Vehicle available space (number of seats / standing room)
Vehicle fuel type
Vehicle size
Emission factors
Background Approach Framework Conclusions

13. Flow chart of framework

14. Outputs from the framework
• The main outputs are:
• Fractional vehicle excess capacity (for individual modes
and a mode weighted value)
• CO2 emissions (per person per week)
Background Approach Framework Conclusions

15. Vehicle Average
Occupancy
Comfort Case Extreme Case
Available
Space
Associated
Excess Capacity
Available
Space
Associated Excess
Capacity
Car (national
average)
1.6 4 60% 5 68%
Car (GM peak) 1.22 4 70% 5 76%
Car (GM off
peak)
1.36 4 66% 5 73%
Local Bus
(national
average)
9.5 70 86% 85 89%
London Bus 19.3 70 74% 85 77%
Examples of vehicle fractional
excess capacity
Background Approach Framework Conclusions

16. Future work within this project
• Scenario construction for future use of urban transport
capacity in emission reductions
• Traffic network modelling of capacity scenarios
• Additional indicators of capacity
Roadspace capacity
Delays and congestion
Background Approach Framework Conclusions

17. Conclusions
• Options available for utilising excess capacity include car
sharing and re-allocation of roadspace for public transport
• Given current occupancy rates for cars and buses, between
60-89% of capacity is excess
• It remains to be seen what the rebound effects and impacts
of induced congestion might be
• Achieving an 80% reduction in emissions by 2050 is
challenging, using excess capacity could contribute to this
Background Approach Framework Conclusions

18. Thanks for your attention
Clare Linton
pmcli@leeds.ac.uk