This presentation has been done in Xi'an Chang'an University and is a slight improvement of the Chengdu one . It concerns the application of transportation complexity theory to optimal driving strategy.

1. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Institut français
des sciences et technologies
des transports, de l’aménagement
et des réseaux
Transportation system complexity
: Optimal driving strategies
Olivier Orfila
TongJi University (High End Foreign Expert)
IFSTTAR-COSYS-LIVIC (Senior Researcher)
olivier.orfila@ifsttar.fr

2. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
What are our objectives?
• We want to mitigate a wide range of
transportation issues (congestion, pollution,
safety, etc)
• In our case: Reduce the negative impact of
road transport on health and environnement:
• Reduce greenhouse gases emissions (GHG);
• Reduce pollutants emissions;
• Reduce energy use;
• All of this without increasing travel time nor
road insecurity.

3. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Regulation is pressing!
• Emissions
standards:
• Increasing
constraints
• COP21 :
• Limit global
warming to 2°C
targetting 1.5°C
Historical fleet CO2 emissions performance and current or proposed
passenger vehicle standards (ICCT, International Council on Clean
Transportation):

4. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
What about passenger cars?
• Fuel use data in the US (IEA)
• In France, 55% of GHG
emissions are due to light duty
vehicles (source : MEEM,
french ministry of ecology)

5. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Role of infrastructure,
vehicles and drivers
Drivers :
•Driving
•Use choice,
maintenance, client
choices
Vehicle :
•Mass,
aérodynamics
•Engine
•ADAS
•Tires,…
Infrastructure :
•Geometry
•Road texture
•Urban planning
•ITS

6. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
USE CASE OF OPTIMAL
DRIVING: ECODRIVING
First part

7. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
A few energy reach the
wheel and we are still
spoiling it!
Ecodriving =
cooking leftovers
Ecodriving definition proposal

8. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Ecodriving history
Toyota, Glass of
water
BMW, econometer

9. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Ecodriving definition
« Ecodriving is a strategy to reduce fuel use by following several
advice: do not accelerate strongly, reduce speed, keeping low
RPMs, anticipate traffic. » M. Barth, K. Boriboonsomsin, 2009. Energy and
emissions impacts of a freeway-based dynamic eco-driving system
« Ecodriving should not be confused with hypermiling wich
neglects safety to reduce fuel use while ecodriving has no trade-
off » J. N. Barkenbus, 2010. Eco-driving: An overlooked climate change initiative
« Ecodriving aims at following a vehicle safely in order to reduce
energy use on the long term » M.A.S. Kamal, M. Mukai, J. Murata and T.
Kawabe, 2010. On board eco-driving system for varying road-traffic environments
using model predictive control

10. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Ecodriving definition proposal
• Ecodriving is a set of driving technics, dealing with all driving tasks,
aiming at minimizing the energy losses and/or emissions rate of the
driven vehicle, from an origin to a destination, without trading-off
safety nor total travel time.
• Note: Ecodriving is a real time multi objective optimization process.

11. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Is ecodriving efficient?
Wengraf I.: Easy on The Gas, The effeciteveness of ecodriving, RAC Foundation, London,
2012, pp.16-17
Experimental : 20 weeks
before and after ecodriving
training (golden rules)
Isuzu Motors: Fuel
economy challenge: One
trip before and one after

12. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Some ecodriving research
questions
• Can ecodriving famous golden rules, taken
one by one:
• Reduce the energy used by the concerned
vehicle?
• Reduce the emissions rates of the concerned
vehicle?
• Improve road safety for the concerned vehicle?
• Reduce congestions?
• Increase comfort?
• Reduce traffic noise?
• And what about a whole network?

13. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
IFSTTAR ecodriving research
methodology
• Ecodriving optimization• Ecodriving modelling
• Ecodriving assistance
systems
• Impact of ecodriving
Smart and Green ACC
ddriver
Tdriver
V
d
Vi
g
SAGA Mode
Target Speed
Target Acc.
ErrorFlag
Accuracy
Dyn. Limit
Func. Limit
70
Vdriver
eHorizon
Fuel use in congested urban
traffic
Fuel use in nearly congested
interurban roads
δ
ωmax2
Olivier Orfila, Guillaume Saint Pierre, Cindie Andrieu. (2012) « Gear Shifting Behavior
Model for Ecodriving Simulations Based on Experimental Data », EWGT2012
H. T. Luu, 2011, Développement de méthodes de réduction de la consommation
en carburant d’un véhicule dans un contexte de sécurité et de confort : un
compromis entre économie et écologie. Thèse de doctorat, Université d’Evry
Orfila O., Saint Pierre G., Messias M. (2014), « Development of an ecodriving
assistance application for nomadic devices performing real-time and post trip
coaching for road vehicles », TRA 2014, Paris, La Défense.
O. Orfila, 2011, Impact of the penetration rate of ecodriver on traffic and fuel
consumption, YR2011, Copenhaguen

14. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Methodology: an ecodriving
modelling
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion
Ecodriving
parameters
Ecodriven
vehicles
Normally
driven
vehicles
Traffic
demand
Road
network
Traffic micro
simulation
Fuel consumption
Traffic indicator
(mean speed)
%
•IDM (Intelligent
Driver Model)
Treiber, 2000
•Gipps model 1981
(AIMSUN)
•Interurban
•Urban
•Free traffic state
•Intermediate traffic
state
•Congested traffic
state
2 types of roads x 3 traffic states x 11 proportions of ecodrivers x 10 replications = 660
numerical tries

15. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Traffic micro simulation on urban
roads
• Gipps model (Gipps, 1981) with Aimsun (TSS)
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion
0%
50%
100%
Free
Intermediate
Congested

16. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
RESULTS:
Interurban roads
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion

17. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Results : interurban road – free
traffic
• Fuel consumption
• Slight and steady decrease
• Fuel consumption reduces
by 7.7%
• Traffic indicator
• Slight decrease (9.1%)
• 2 minutes lost on a 20
minutes travel
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion
Optimal proportion of ecodrivers : 100%

18. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Results : interurban road –
intermediate traffic
• Fuel consumption
• Non linear variation
• From 0 to 20% of ecodrivers
: -8.5%
• From 0 to 100% : +2.4 %
• Traffic indicator
• Sharp decrease : -38%
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion
Optimal proportion of ecodrivers : 20%

19. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Results : interurban road –
congested traffic
• Fuel consumption :
• Strong reduction : -35.8%
• Traffic indicator
• Sharp decrease : -55%
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion
Optimal proportion of ecodrivers : 30%

20. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
RESULTS:
Urban roads
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion

21. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Results : urban road – free traffic
• Fuel consumption
• Slow decrease : -9.8 %
• Traffic indicator
• Strong decrease : -19.7%
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion
Optimal proportion of ecodrivers : not defined

22. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Results : urban road –
intermediate traffic
• Fuel consumption
• Non linear variations : -7.6%
• Traffic indicator
• Non linear variations : -
32.3%
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion
Optimal proportion of ecodrivers : not defined but 80% should be avoided

23. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Results : urban road – congested
traffic
• Fuel consumption
• Strong effect: -19.6%
• Traffic indicator
• Nearly steady
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion
Optimal proportion of ecodrivers : 100%

24. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Conclusions
• Ecodriving is efficient at a global point of
view for energy use only.
• The optimal proportion of ecodrivers varies
with the situation.
• In some situations, the fuel
consumption increases with the
proportion of ecodrivers
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion

25. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Proposed solutions for
ecodriving
• Short term: promote ecodriving on
identified situations
• Middle term: giving real time advice to the
driver
• Long term: develop a strategy to manage
a whole network.
• Change subsystem definition
Impact of the penetration rate of
ecodriving on fuel consumption and traffic
congestion

26. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
STUDYING TRANSPORTATION
SYSTEM COMPLEXITY
Second part

27. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Transportation system and life cycle
Automotive
industry
energy
production
infrastructure
construction
multimodality
recycling
depolluting
maintenance
highways –
periurban
roads
urban
networks
rural
networks
Usage

28. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Decomposing the transportation
system
• Structural analysis:
• Physical structures
• Administrative structures
• Studying interaction between elements

29. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Road transportation system
Physical
• Infrastructure:
• Road, power supplies,
power stations, public
transport stations, ITS,…
• Vehicles:
• Private cars, shared cars,
trucks, buses, bikes,
motorbikes,…
• Users:
• drivers, pilots,…
Administrative
• Government
• Local collectivities:
• Province, City, District,
• Private companies:
• vehicle sharing, vehicle renting,
infrastructure managers
• Associations:
• User association, road
association, vehicle
manufacturers association
• Laboratories:
• Resaerch centers, universities
We should think about
interactions and scales!

30. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
HOW TO DEFINE A
SUBSYSTEM LIMITS
Third part

31. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Defining the subsystem limits
• Selecting a subsystem is a complex task
that generally consists in finding the good
study scale (select the right numbers of
actors, select the right study area such as
a street, a quarter, a city, a province or a
country).
• A wrong selection leads to suboptimal
solutions or cons-productive results.

32. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Isolated system, closed system,
opened system?
• Isolated system: that is totally separated from other
systems and that does not interact with others.
• Closed system: system exchanging energy with
other systems
• Opened system: system exchanging energy and
matter with other systems

33. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Co-evolution
• Host, parasitic co-evolution: metaphoric,
Road (host) and car (parasitic)
• Combined co-evolution:
• Antagonistic : Taxis and private cars service,
buses and trains.
• Symbiosis : commercial centers and cars,
thermal engine and fuel.
• Diffuse co-evolution: ITS, as related to
several transportation means.

34. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
Conclusion
• When trying to mitigate very important
issues we might first have to:
• have a good overall vision of the global
tranportation system and subsystems and
their interactions
• define the subsystem in accordance with
transportation system decomposition and by
interacting with transportation actors.
• make research studies to proove the concept
efficiency

35. Institut français des sciences et technologies des transports, de l’aménagement et des réseaux
www.ifsttar.fr
THANK YOU VERY MUCH FOR
YOUR ATTENTION!