Gaelle Le Bars - HDMGlobal - Egis

1. Gaëlle LE BARS
Egis - Pavement and asset management department
“Using HDM4 to support decision making”

2. Roads issues
• Road costs include:
• Costs for the construction and the maintenance,
• Costs for the users and for travel time.
• Roads condition are linked to transport costs
• Roads are directly linked to sustainable development issues :
• Economy : transport costs, construction costs, maintenance costs, ….
• Environnemental : natural and human environment ..
• Social : Human développement, health, éducation,
• An economical optimum must be found to reduce transport cost regarding
available budget.

3. Roads management
Regarding the user :
• Requirement for a level of service :
• Requirement to drive to their destination
• In the best conditions : transport time, comfort,…
• In safety conditions
Regarding the asset manager
• The asset manager must guarantee this level of service
• Durability
• .

4. Road asset management
• A road network has an important asset value over the life cycle.
• Roads are directly linked to sustainable development issues :
• Economy : transport costs, construction costs, maintenance costs, ….
• Environnemental : natural and human environment ..
• Social : Human développement, health, éducation,
Decisions regarding road investment are often « political » decisions regarding both :
A responsible vision
A technical vision

5. By using HDM-4
as a decision
making tool
C
O
N
D
I
T
I
O
N
?
Where?
What?
priorities?
What solution?
I
S
M
O
N
E
Y
W
E
L
L
U
S
E
D
?
How much ?
How answering those questions ?

6. • Highway Development and Management model
• Strategic decision tool for paved and unpaved roads :
• Strategical analysis : long term 10 / 30 years
• Works programs : middle term 2 / 5 years
• Projects study : short term
• HDM IS ...
• Determinist ( # probabilistic)
• Quantitativ ( # qualitativ)
• Algorithmic ( # expert system)
HDM-4 Model
6

7. 7
HDM – 4 allows :
•Analyse the pavement behaviour over the life cycle and calculate :
• The annual prediction of the pavement behaviour of a road network
• The effects of the maintenance and road improvement
• A advantage/cost analysis of the roads use
• Calculate economical indicators such as the Net Present Value (NPV), the
Economic Internal Rate of Return (EIRR), the Benefit Cost Ratio (BCR).
• Define maintenance plan, strategy, project that ensure the sustainability
of the road network maintenance
• To evaluate technically and economically road projetcs
• To define maintenance budget over the long term at the network level

8. 8
• Predicts road network performance as a function of:
• Traffic volumes and loading
• Road pavement type and strength
• Maintenance standards
• Environment / Climate
• Quantifies benefits to road users from:
• Savings in vehicle operating costs (VOC)
• Reduced road user travel times
• Decrease in number of accidents
• Environmental effects (vehicle emissions)
HDM-4 model

9. 9
• By using laws, methods, well established and accepted
• for paved and unpaved roads (mainly based on IRI = International Roughness
Index )
• Laws on the works effects on the users and the vehicle
• by testing strategies with or without budget constraint
• Maximise the Net Present Value
•  long term benefit
• Maximise the level of IRI
•  long term level of service
HDM-4 model

10. HDM 4 Approach
Network matrix
HDM-4 strategy
Unconstrained
Under budget
constraint
Maximizing NPVMaximizing NPV Maximizing IRI
Alternatives for
maintenance
Level of serviceBenefit
Network analysis
Results

11. HDM 4 Approach
• The aim :
• Global approach : design and maintenance
• Optimization of the global cost
• Budget allocation
• Road network performance predictions
• The difficulties:
• Prediction of the traffic growth
• Condition of the existing roads
• Prediction of the deterioration of the pavement ( traffic, climate, material
characteristics,…)
To make decision
• At the project level
• At the network
level

12. • Creation of integrated road data base :
• inventory, history, traffic, survey
• Introduce modern practices for maintenance
management :
• Cost-effective maintenance operations
• Optimization at three levels :
• Strategy
• Program
• Projects
Choosing
appropriate
alternatives
Defining
intervention
criteria
Road functional
Classification
Primary, Secondary
Condition
class
Traffic
class
Good Fair Poor High Medium Low
How using HDM-4?

13. Example of an analysis of the optimal level of investment
« International » Network
0
1
2
3
4
5
6
7
8
9
10
100 200 300 400 500 600 700 800 900
Budget (Mi USD)
IRI
Local Network
0
2
4
6
8
10
12
14
100 200 300 400 500 600 700 800 900
Budget (Mi USD)
IRI
Benefits / Budget
6 000
7 000
8 000
9 000
10 000
11 000
12 000
100 200 300 400 500 600 700 800 900
Budget (Mi USD)
BA(MiUSD)
IdéalOptimiséCrise
Budgets total (Mi USD)
MiUSD
200 300 400 500 600 700 800
Budget per category
Local
Secondaire
Primaire
International

14. Economical analysis
• Cost benefit analysis
• base” case (example : Routine + Rehabilitation when IRI > 8) = “do minimum”
• proposed alternative interventions = “do something”
• road condition impact – measured by change in roughness (IRI)
• cost (budgetary) impact – measured by Net Present Value (NPV)
• Objectives
• Simulates the impact of different alternative interventions over time (life-cycle
analysis)
• Computes quantities and costs for each alternative
• Compares each proposed alternative to the base case
• Computes economic indicators (Net Present Value NPV)

15. • Economy :
• The costs of construction and maintenance
• Transport costs
• Economical indicators
• Social :
• Human development impact, local development,…..
• Accident costs
• Environnement :
• Pollution, green house gaz
• Landscapes,
• Energy consumption
HDM-4 and sustainable development

16. Budget allocation : some results
Type of works vs length of the network
Maximising NPV
28%
42%
29%
1%
Routine
4 AC
6 A C
8 AC
% of the
network Length (km)
Routine 28% 499
4 AC 42% 751
6 A C 29% 526
8 AC 1% 14
Budget over the 10 year analysis
0
10
20
30
40
50
60
70
80
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Year to perform the works
Budget(MillionEuros)

17. Stategy analysis :some results
• With respect to investment budgets:
• change in average roughness (IRI)
• change in NPV
0
50
100
150
200
80 85 90 95 100 Without
budget
constraints
Budget (Millions Euros)
NetPresentValue(MillionsEuros)
0
1
2
3
4
5
6
80 85 90 95 100 Without
budget
constraintsBudget (Millions Euros)
AverageRoughnessIRI

18. Strategy analysis : some results
“Optimised” strategies:
600 Km of Major maintenance
410 Km of Medium maintenance
– “Fixed” strategies:
– 880Km of Major maintenance
0%
20%
40%
60%
80%
100%
RQI: Scenario 1 Optimised strategies
VP
F/P
E/G
0%
20%
40%
60%
80%
100%
RQI: Scenario 1 Fixed strategies
VP
F/P
E/G

19. Asset value : some results

20. The advantages of using HDM-4
• Fast constitution of a road data base
• Production of a strategy study in a relatively short time.
• Global overview of the maintenance needs at a road network level.
• Restitution of main results in an usual format
• Definition of a complete chain of decision for preparation pluri-annual program
• Introduction of cost-efficiency principles in maintenance decisions
• Highlighting of the current technical potential
• Offer a framework for technical improvement of maintenance staff

21. • Strong model to support decision making
• An international reference tool that uses well-established and globally researched
concepts, methods
• Accurate and usable outputs
• Possible local adaptation of the tool calibration to be convenient to several context
• Taken into account the sustainable development and asset value (long term
approach)
• A technical and development support (HDM Global) to guarantee the update of the
tool regarding technical and technological evolutions
HDM-4 : a strong model

22. • HDM-4 helps to answer these questions
That’s why HDM-4 is a very strong
support to decision maker
Conclusion

23. Información
Nombre
Le Bars Gaëlle
Cargo del Relator
Pavement and asset management manager
Empresa
Egis
Sitio web
http://www.egis.fr/
Correo Electrónico
gaelle.le-bars@egis.fr