1. Corsi di laurea magistrale in Ingegneria dei Sistemi Idraulici e di Trasporto - Gestionale Corso di GESTIONE DEI SISTEMI DI TRASPORTO “Informazioni all’ utenza”

2. ITS (Intelligent Transportation Systems), -ATIS (Advanced Traveller Information Systems) - ADAS (Advanced Driving Assistance) -ATMS (Advanced Traffic Information Systems)

3. ATIS sono mirati ad influenzare le scelte di viaggio (ad esempio scelte di percorso) degli utenti, fornendo loro informazioni e/o suggerimenti sul contesto di traffico che presumibilmente incontreranno durante lo svolgimento del loro itinerario tra origine e destinazione dello spostamento;

4. ADAS tendono a modificare le scelte di guida (comportamento al volante, per intenderci) in funzione del contesto che influenza la marcia del veicolo, in tale modo vengono influenzate le variabili fondamentali del deflusso sull’infrastruttura (tipicamente, flusso, velocità densità delle correnti veicolari e variabili di deflusso microscopico con esse correlate);

5. ATMS agiscono attraverso il controllo semaforico, delle intersezioni e delle regole di deflusso/circolazione, sono finalizzati a influenzare il meccanismo con cui i flussi di traffico si propagano da un elemento al successivo di una infrastruttura stradale e/o tra gli elementi di una rete di trasporto e (solo parzialmente) hanno un effetto indiretto anche sulle scelte di viaggio

6. intelligenza cognitiva permette una sempre più ampia, profonda ed accurata coscienza/conoscenza del contesto in cui le scelte (di viaggio e/o di guida) avvengono. L’incremento di intelligenza cognitiva permette tipicamente di ampliare il campo delle possibilità/alternative di scelta a disposizione e/o di aumentare l’accuratezza con cui la utilità delle possibili alternative può essere conosciuta/stimata

8. intelligenza decisionale OGGI è lasciata al guidatore; in altri termini, la responsabilità del processo di scelta è interamente del guidatore/viaggiatore, eventualmente supportato nell’implementazione di tale processo da appositi sistemi di supporto L’introduzione di un maggiore grado di intelligenza decisionale tecnologica, invece, prevede la possibilità di spostare tutto o parte del processo decisionale da un soggetto umano ad un soggetto tecnologico

9. Information quality Static InstantaneousEnhanced PredictiveAccurate 9Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS Typically based on free-flow travel-times or average travel times (e.g.: traditional TomTom navigation) Dynamic information, based on instantaneous travel-times (or queue lengths) measured by different kind of sensors (e.g. traditional Broadcast info and/or VMS) Measures from different sensors are integrated. A broad picture of the transportation system is computed. Customised Information is dispatched via personal devices with reference to current travel choice and alternatives. (e.g. dynamic TomTom experiments, OctoTelematics) Based on actual travel-times (forecast required) Anticipatory: a sort of time-machine in which the “Grandfather” paradox has to be solved (forecasting and consistency)

10. The role of transportation models StaticInstantaneousEnhancedPredictiveAccurate Cino Bifulco - 05/11/201010 The importance of information accuracy and travellers’ compliance in ATIS Technological aspects are dominant Transportation modeling aspects are dominant Increasing technological complexity Increasing Transportation Models complexity May be… a graph is enough! Sensors required (and the ability of using traffic/travel data) A network of sensors and a traffic network: models for spatial augmentation of information Traffic/Transportation models with forecast Transportation Models with: -Explicit travelers’ reaction models -Elasticity of travelers’ compliance to info accuracy -Algorithms for the anticipatory route guidance problem

11. The anticipatory-route-guidance problem (1) The Grandfather paradox (http://en.wikipedia.org/wiki/Grandfather_paradox)http://en.wikipedia.org/wiki/Grandfather_paradox – A man travelled back in time and killed his biological grandfather before the latter met the traveler's grandmother. – As a result, one of the traveler's parents (and so the traveler himself) would never have been conceived. (This would imply that he could not have travelled back in time after all, which means the grandfather would still be alive, and the traveler would have been conceived allowing him to travel back in time and kill his grandfather) The solution is that… – Travelling back in time not all the actions can be carried out by the traveler. – Only a restricted set of actions is feasible and this is the set of the actions that are consistent with the future the traveler comes from. Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 11

12. The anticipatory-route-guidance problem (2) The anticipatory route guidance is the forward-case of the Grandfather paradox (but being forward is not a paradox) – A prediction of future traffic patterns is made. Such a prediction is dispatched to travelers and they use it in order to make their travel choices. However, the aggregate result of travel choices are traffic patterns. – As a result, the prediction of traffic patterns is disrupted Traffic models for ATIS have to explicitly implement travelers’ reaction to information – Traffic patterns have to be searched among these consistent with travelers’ reactions Bi-level-programming approach Hierarchical fixed-points approach … Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 12

13. Inadequateness of the pure technological approach also in simple contexts Cino Bifulco - 05/11/201013 The importance of information accuracy and travellers’ compliance in ATIS The travel time from origin A to destination B is required Technological solution 1 – I’m able to measure/estimate (somehow) the travel time of each arc at time t – TT t AB = Σ a tt t a (instantaneous travel-time) Technological solution 2 – Floating car datat = time at which the vehicle is detected in B t-Δt = time at which was detected in A – TT t AB = Δt (actual – but backward – travel time) The only chance for dispatching actual+forward travel times is to use (complex) traffic models with forecasting abilities In the general case of dynamic networks, none of these times will be experienced by the traveller

14. What is enabled by accurate information? A great role for traffic/transportation modeling is not only once ATIS are implemented but also in order to drive ATIS implementations – What can be expected? – Which are the results that can be achieved? – What is utopian? – … and… most of all … what is needed for successful implementations? In the following 2 examples (only results) strictly related to the role of the information accuracy (and of the travelers’ compliance with information) – The examples refer to ATIS applications in recurrent traffic contexts – Different considerations apply in case of non-recurrent (e.g. emergency) contexts Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 14

15. ATIS for optimisation of traffic patterns? (Bifulco and Simonelli, 2007)  Information modifies travelers’ choices  It could be nice (especially in urban areas) to push traffic patterns toward desired configurations (e.g. system-optimum instead of user-optimum/equilibrium) Inaccurate information have to be dispatched ○ Otherwise travelers still will chose according to user-optimum Inaccurate information → less compliant travelers less compliant travelers → less flow redirected from optimum toward system-optimum  The strategy can be successful if: The desired travel pattern is quite similar to the “natural” one ○ A reduced amount of compliant travelers is needed ○ A reduced inaccuracy is needed The balance between (in)accuracy and required compliance can be reached  Most of the times “the game’s not worth the candle” Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 15

16. ATIS for optimisation of traffic patterns? Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 16

17. ATIS for effective signal-setting design  One of the most relevant measures for optimization of traffic patterns is (especially in urban areas) proper signal setting Even if this can be obtained by adaptive/advanced traffic management systems (ATMS), an effective and robust reference solution is required ○ Regulation around the reference solution allow for effective ATMS  Once searching for the reference signal-setting solution Provided that signal settings depend on traffic volumes and vice versa, an equilibrated solution (consistent with traffic assignment) has to be searched Also provided that ○ the equilibrated solution has to be reached by the traffic system (solution observable and to be reached, in Systems Theory) ○ The traffic is regulated around the equilibrated solution A stable+equilibrated solution has to be searched Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 17

18. ATIS for effective signal-setting design Solutions of the signal-setting problem (thank to prof. G.E. Cantarella – Università di Salerno) – Unconstrained (first-best) – Equilibrium constrained (second-best) – Equilibrium + Stability constrained (third-best) The only feasible solution is the third-best Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 18

19. ATIS for effective signal-setting design  Using ATIS in order to make the first or the second-best solutions admissible  Making admissible the first-best solution is identical to force user-equilibrium toward system-optimum. Generally, this is not feasible  Making admissible the second-best solution can be obtained by expanding its stability domain…THIS IS A JOB FOR (ACCURATE) ATIS Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 19

20. (ACCURATE) ATIS and traffic system stability  The stability of traffic networks is generally studied by analyzing a proper discrete-time dynamic (non-linear) system  The most accepted dynamic formulation for traffic networks is based on exponential smoothing for both the learning/forecasting submodel and the choice-updating submodel f t = α B D p(- B T x t ) + (1-α) f t-1 x t = β B c(f t-1 ) + (1- β) x t-1  The equilibrium solution can be viewed as a particular fixed- point attractor of the dynamic process f * = B D p(- B T c(f * ) ) ( c * = c(f * ) )  The equilibrium stability depends on the eigenvalues of the transition function of the dynamic process, evaluated around the equilibrium Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 20

21. (ACCURATE) ATIS and traffic system stability  In absence of ATIS, eigenvalues of the matrix J 11 =(1-β)·I J 12 = β·J c (f) J 21 =α· (1- β)· J f (c) J 22 = (1- α)· I + α·β · J f (c)· J c (f)  In presence of ATIS and for accurate information, eigenvalues of the matrix (Bifulco and Simonelli, 2010) J 11 =(1-β)·I J 12 = β·J c (f) J’ 21 =(I – α· max · J f (c)·J c (f)) -1 J 21 J’ 22 =(I – α· max · J f (c)· J c (f)) -1 J 22  max ·= ATIS market-penetration = max travellers' compliance = actual travellers compliance in case of accurate info Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 21

22. (ACCURATE) ATIS and traffic system stability  Eigenvalues of the dynamic process can be analyzed with reference to a transformed problem in which:  Associated eigenvalues depends only on J c (f) and J f (c)  The eingenvalues have to be (in the Argand-plane of the imaginary numbers) within an elipse that only depends ○ On α and β in absence of ATIS ○ On α, β and max in presence of (accurate) ATIS  The effect of max is to extend the Elipse, so (for given α and β) to extend the stability domain Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 22

23. (ACCURATE) ATIS and traffic system stability  The previous result in terms of enhanced stability under ATIS …  strongly depends on the accuracy of the information  is in (apparent) contrast with many findings in literature that claim for traffic instability in case of high diffusion (market penetration) of ATIS  Because accuracy and elasticity of travelers’ compliance with information were not properly taken into account  Actually, ATIS are a good tool for stabilizing traffic networks (and can be effectively coupled with other measures like as ATMS) Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 23

24. Other possible insights  The theory behind the accurate ATIS can be employed in order to show that  The market of the Advanced/Adaptive information is limited by the accuracy of the dispatched information  If the market penetration is low, the problem of the information accuracy (anticipatory information) is relatively easy to be solved  If the market penetration tends to be high, the accuracy problem grows. If unresolved, the compliance decreases with respect to the market penetration and on the medium term the market penetration decreases as well. The market equilibrates it-selfs…  High accuracy = High market penetration  Low accuracy = Low market penetration  The accuracy of the information corresponds to the share of market of adaptive information services  May be it is impossible to have (on the long term) several content-providers for traveler information  Competition of different subject should be in service-providing (e.g. different technologies, different user experience, different cost, ecc) Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 24

25. Conclusions  ATIS are not only a technological problem  Issues related to ATIS accuracy and to travelers’ compliance with information can lead to unexpected conclusions if deeply investigated  Pure technologistics should establish strong collaboration with traffic and transportation analysts (and vice versa)  ATIS, as well as other ITS (Intelligent Transportation Systems) applications, need for the establishing of a new integrated scientific discipline  ITS need for the establishing of new dedicated research and development centers Cino Bifulco - 05/11/2010 The importance of information accuracy and travellers’ compliance in ATIS 25