Renaud Sarrazin Belgian Road Research Centre, Université Libre de Bruxelles Yves De Smet

1. About the use of D-Sight in the performance evaluation of road projects for sustainable road safetyComputing and Software for MCDM – MCDM 2011 Renaud Sarrazin Belgian Road Research Centre, Université Libre de Bruxelles Yves De Smet Université Libre de Bruxelles Quantin Hayez Decision Sights 21st International Conference on Multiple Criteria Decision Making Monday 13 June 2011 – Jyväskylä, Finland

2. Using D-Sight for the evaluation of sustainable road safety « • Introduction “Road safety will play an important role in transport policy 2010 – 2020, as lowering the number of road users' casualties is key to improving the overall performance of the transport system.” “In view of achieving the objective of creating a common road safety area, the Commission proposes to continue with the target of halving the overall number of road deaths in the European Union by 2020 starting from 2010.” European Commission, 20/07/2010 Towards a European road safety area: policy orientations on road safety 2011-2020 “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs. […] The world must quickly design strategies that will allow nations to move from their present processes of growth and development onto sustainable development paths. This will require policy changes in all countries.” United Nations World Commission on Environment and Development (WCED), 1987 Bruntland rapport – Our Common Future »

3. Using D-Sight for the evaluation of sustainable road safety • Framework of the research • Context

4. + Using D-Sight for the evaluation of sustainable road safety • Framework of the research • Road safety & sustainable development • A posteriori approach (accident statistics) • Economic evaluation only (few or any environmental or social concerns) • A priori evaluation (preventive actions) • Definition of road safety: elementary triangle of road safety Accidents in Belgium: • From 18% to 28% are related to an unsafe infrastructure • More than 55% on rural roads • Improve infrastructure-related road safety on rural secondary roads • Awareness of sustainable development concerns

5. 1. Planning 2. Pre-design (draft) 3. Design (detailed) 4. Construction + 5. Opening & Exploitation Objective : evaluating the sustainable road safety performance at the pre-design stage. Offer to the decision maker a support (i.e. a decision aid) in the selection of an alternative. Using D-Sight for the evaluation of sustainable road safety • Framework of the research • Design process of an infrastructure

6. Using D-Sight for the evaluation of sustainable road safety • Research motivations • Multicriteria decision aid problem • Typical MCDA problem: • Alternatives: draft alternatives of a project • Criteria: sustainable road safety performances • Aim: ranking of the alternatives in order to select the best one • Definition of a set of criteria: • Road infrastructure and road environment performance • Sustainable concerns • Data should be available during the design process • Important stage of modelling and creation of data • Development of new criteria constitutes a full and complex problem

7. Using D-Sight for the evaluation of sustainable road safety • Research motivations • Multicriteria decision aid problem

8. Using D-Sight for the evaluation of sustainable road safety • Methodology – MCDA problem • Definition of a set of criteria • Infrastructure – Road legibility and consistency • To maximise • Driver’s mental representation of the road • Importance of some roadway geometric design elements • Sight distance: distance required to avoid an obstacle on the road or to stop at an intersection • Control of the adequacy of the operating speed by measuring the sight distance on the n sections of the road : Fig. 1 - Illustration of the stopping sight distance when approaching an intersection (PIARC – MSR, 2003)

9. Using D-Sight for the evaluation of sustainable road safety • Methodology – MCDA problem • Definition of a set of criteria • Infrastructure – Visibility • To maximise • Roadway elements and equipments which convey visual information • Positive or negative influence • Complex effects (or combination of effects) • Lack of information about this topic • Measure of the coefficient of visibilityαk of the m roadway elements and equipments of the road :

10. Using D-Sight for the evaluation of sustainable road safety • Methodology – MCDA problem • Definition of a set of criteria • Infrastructure – Safety equipments • To maximise • Prevent run-off accidents or head-on collisions, or reduce them severity • Lack of information about this topic • Temporary scale • Measure the influence of safety equipments on the reduction of accidents severity:

11. Using D-Sight for the evaluation of sustainable road safety • Methodology – MCDA problem • Definition of a set of criteria • Infrastructure – Road surface quality • To maximise • Poor road surface quality + inappropriate speeds = high risk of accidents • Performance indexes about quality parameters • PIR: transverse evenness • PIS: skid resistance • PID: drainability • PIWC: sensitivity to winter conditions • Index which measure the global quality of road pavements: Fig. 4 – Drainability (BRRC) Fig. 3 – Sensitivity to winter conditions (BRRC) Fig. 2 – Transverse evenness (BRRC)

12. Using D-Sight for the evaluation of sustainable road safety • Methodology – MCDA problem • Definition of a set of criteria • Infrastructure – Protection of Vulnerable Road Users (VRU) • Secondary roads: multimodal nature • High risk of accidents for pedestrians, bicyclists and motorcyclists (VRU) • Development of safety indexes • Bicyclists - Bicycle Safety Index (CBSI): • Suitable equipments required on straight sections and intersections • Operating speed of the motorized traffic • Geometric design parameters • Volume of traffic • Roadway equipments

13. Using D-Sight for the evaluation of sustainable road safety • Methodology – MCDA problem • Definition of a set of criteria • Infrastructure – Protection of Vulnerable Road Users (VRU) • Pedestrians - Pedestrian Safety Index (CPSI): • Suitable equipments required on straight sections and crossings • Motorcyclists - Motorcyclist Safety Index (CMSI): • Slippery surfaces or road markings • Roadside safety barriers • Global safety indexto evaluate the level of safety for vulnerable road users on the road (CVRU):

14. Using D-Sight for the evaluation of sustainable road safety • Methodology – MCDA problem • Definition of a set of criteria • Infrastructure – Work zones • Protection of workers and road users during the reconstruction and maintenance activities • Impact on accessibility and costs • Lack of information about this topic • Any criterion has been developed yet • Further research • Services – Emergency and Trauma care • To maximise • Evaluation of the quality of the emergency and trauma care services • Complex to define • Subjective scale from very bad to very good • Further research

15. Using D-Sight for the evaluation of sustainable road safety • Methodology – MCDA problem • Definition of a set of criteria • Environmental – Greenhouse gases emissions • To minimise • Most frequently used criterion to represent environmental concerns • Construction and maintenance activities • Traffic activities not considered (for the moment) • Summing the emissions generated by all the activities of the road: • Environmental – Noise pollution • To minimise • Noise generated by the vehicular traffic on the roadway • Very complex (many parameters) • Limitation to the characteristics of the road surface • Evaluation of the noise sensitivity of the road surface material

16. Using D-Sight for the evaluation of sustainable road safety • Methodology – MCDA problem • Definition of a set of criteria • Economic – Construction costs and Maintenance costs • To minimise • Evaluation of the economical performance of the road project • Criteria expressed in euros (€) • Summing the costs of all the construction or maintenance activities • Social – Mobility and accessibility • To maximise • Accessibility: quantification of the efficiency of a road network • Important to guarantee a good mobility and accessibility of a road • Speed Efficiency Coefficient (SEC) which measures the extent of a road that performs at least as well as the target or threshold speed:

17. Methodology – MCDA problem Global methodology of the problem Evaluation and multicriteria optimisation tool “MULTISED/D-SIGHT” “MULTISED” premodelling tool Ranking of the draft alternatives of the project (PROMETHEE & GAIA) Sensitivity analysis of the problem Evaluation on criteria for each alternative - Development of the evaluation table (outputs) Parameters of draft alternatives (inputs) Multicriteria evaluation and selection of the best draft alternative with respect to the preferences of the Decision Maker Visibility, legibility and consistency, protection of VRU, environmental impact, services, construction and maintenance costs, etc. Data infrastructure (geometry, design, materials), volume of traffic, operating speed, safety equipments, etc. Using D-Sight for the evaluation of sustainable road safety

18. Using D-Sight for the evaluation of sustainable road safety • Case study • Pilot project : N243a (Walhain, Walloon Brabant, Belgium) • Redevelopment secondary road in a rural area • Main characteristics of the road project: • Length: 2.4 km • Number of lanes: 2 • Available width: 13.70 m • Intersections: 5 • Cycle lane: Yes • Average daily traffic: 3250 vpd

19. Using D-Sight for the evaluation of sustainable road safety • Case study • Pilot project : N243a • Type of road surface material • Geometric design parameters • Vertical alignment • Bicyclists equipments • Roadside equipments • Maintenance activities • … • Calculation of the evaluation table by using the pre-modelling tool • 7 draft alternatives

20. Using D-Sight for the evaluation of sustainable road safety • Case study • Pilot project : N243a • Using the D-SIGHT software to assess the quality of these alternatives • Definition of the preferences parameters (column Weights) • On the basis of subjective judgements • Judged not too arbitrary by a road safety expert

21. Using D-Sight for the evaluation of sustainable road safety • Case study • Pilot project : N243a • Ranking of the 7 draft alternatives (PROMETHEE II net flow scores) • Alternatives 3, 4 and 7 seem to be the best according to DM’s preferences

22. Using D-Sight for the evaluation of sustainable road safety • Case study • Pilot project : N243a • Analysis of the GAIA plane: • Alternatives and Decision Stick • Some criteria are highly correlated • Two groups of criteria are in opposition: complex problem • DM Brain: complex problem

23. Using D-Sight for the evaluation of sustainable road safety • Case study

24. X X X Using D-Sight for the evaluation of sustainable road safety • Case study • Pilot project : N243a • Sensitivity analysis: stability level of the first position • Problem quite robust

25. Using D-Sight for the evaluation of sustainable road safety • Conclusions and prospects • Conclusions • Preliminary study • First encouraging results • Many specificities due to the complexity of the road safety theory… • …and the draft design stage of road projects • Innovative concept (preventive approach and recognition of sustainability) • Actual contribution already bring some added value in this application field • Future prospects • Improvement of the existing set of criteria • Definition of missing criteria • Better understanding of some complex phenomenon about road safety • Recognition of the uncertainty (unpredictable behaviour of road users) • Case study: it will be crucial not to particularize the evaluation

26. Using D-Sight for the evaluation of sustainable road safety • Thank you for your attention • Questions ? Renaud Sarrazin BRRC / CoDE-SMG (ULB) r.sarrazin@brrc.be +32/499526143 http://www.brrc.be