1. 1 I MPROVING ROAD SAFETY AND OPERATIONS OF URBAN ARTERIALS: The study-case of Viale Ariosto in Sesto Fiorentino, Florence (Italy) Antonio Pratelli Department of Civil Engineering “Vie e Trasporti” University of Pisa (Italy) CE552 Highway Safety Meeting 7th April 2009

2. 2 Tuscany (Central Italy) Lectures at the IOWA STATE UNIVERSITY – April 2009

3. 3 Sesto Fiorentino (“Florence Belt”) Lectures at the IOWA STATE UNIVERSITY – April 2009

4. 4 Urban street: Park Avenue Length: 1700 mt (1,06 miles) Main intersections: 5 (2 roundabouts + 3 signals) Traffic: 1900-2100 vph (AM peak flow rates) Passing trough vehicles (Master Plan forecasts): 67% VIALE ARIOSTO Lectures at the IOWA STATE UNIVERSITY – April 2009

5. 5 Reducing traffic congestion 4 MAIN GOALS Traffic negative impacts mitigation (pollutions, noise, delays and queues) Enhancing and improving roadway environment and urban landscape Increasing road safety for all road users (vehicles + pedestrians + bicyclists) Lectures at the IOWA STATE UNIVERSITY – April 2009

6. 6 Construction divided into two different lots (due to both functional and economic matters): Lot 1) from Via Querciola to Via Rimaggio (950 m); Lot 2) from Via Pavese to Via Neruda (750 m). THE “ARIOSTO” PROJECT System approach design: the project has been extended to the arterial in its whole. We show some interesting design items, such as: - Querciola and Pavese (roundabout functional improvement); - Gavine and Oca Bianca (traffic calming device); - Neruda (conversion from signal to roundabout ); Lectures at the IOWA STATE UNIVERSITY – April 2009

7. 7 THE “ARIOSTO” PROJECT (2) We show some interesting design items, such as: Querciola and Pavese (roundabout functional improvement); Gavine and Oca Bianca (traffic calming devices); Neruda (conversion from signal to roundabout). Lectures at the IOWA STATE UNIVERSITY – April 2009

8. 8 VIA QUERCIOLA Lectures at the IOWA STATE UNIVERSITY – April 2009

9. 9 VIA QUERCIOLA DESIGN CATEGORY: Improving the present roundabout via geometrical corrections related to the European standards. NEW GEOMETRY FEATURES: INSCRIBED CIRCLE DIAMETER 54,00 m GRASSY CENTRAL ISLAND RADIUS 13,1 0 m CIRCULATORY ROADWAY WIDTH (without shoulders) 10,5 m APRON WIDTH 2,15 m NUMBER OF CIRCULATORY LANES 2 NUMBER OF ENTRY LANES 2 Lectures at the IOWA STATE UNIVERSITY – April 2009

10. 10 VIA QUERCIOLA (before) Lectures at the IOWA STATE UNIVERSITY – April 2009

11. 11 VIA QUERCIOLA (after) Lectures at the IOWA STATE UNIVERSITY – April 2009

12. 12 VIA QUERCIOLA (superimposed) Lectures at the IOWA STATE UNIVERSITY – April 2009 WHITE = actual RED = design

13. 13 VIA QUERCIOLA EXPECTED RESULTS* (AM peak scenario): Entry direction:Present stateDesign stateDifference % 1) VIA TOGLIATTI Average delay = 51 sec/v Average delay = 6,5 sec/v  87 % 99%Queues > 180 m 99%Queues  42 m  77 % (min.) Entry capacity = 983 vph Entry capacity = 1549 vph+ 58 % 2) VIA QUERCIOLA (sud) Average delay = 6 sec/v Average delay = 3,5 sec  42 % 99%Queues = 12 m 0 % Entry Capacity = 615 vph Capacità = 1048 veic/h+ 70 % 3) VIALE ARIOSTO Average delay > 60 sec/v Average delay = 19 sec  68 % (min.) 99%Queues > 180 mt99%Queues = 150 mt  17 % (min.) Entry capacity = 1329 vph Entry capacity = 1658 vph+ 25 % 4) VIA QUERCIOLA (nord) Average delay = 42 sec/v Attesa media = 5,5 sec/v  87 % 99%Queues = 84 m 99%Queues = 30 m  64 % Entry capacity = 582 vph Entry capacity = 1040 vph+ 79 % (*) Values obtained by SETRA model for large roundabouts. Lectures at the IOWA STATE UNIVERSITY – April 2009

14. 14 VIA QUERCIOLA (3D simulation) Lectures at the IOWA STATE UNIVERSITY – April 2009

15. 15 VIA QUERCIOLA (yesterday) Lectures at the IOWA STATE UNIVERSITY – April 2009

16. 16 VIA QUERCIOLA (today) Lectures at the IOWA STATE UNIVERSITY – April 2009

17. 17 GAVINE & “OCA BIANCA” Lectures at the IOWA STATE UNIVERSITY – April 2009

18. 18 GAVINE DESIGN CATEGORY: Traffic calming features obtained by insertion of a median traffic island to carry out: 1) safe island for pedestrians crossing the road; 2) left turns elimination; 3) make a severe obstacle to bikers overpassing the bus where the bus stop is placed. Lectures at the IOWA STATE UNIVERSITY – April 2009

19. 19 GAVINE EXPECTED RESULTS: Accidents reduction due to: Suppression of all the left turn conflict points. Better protection offered to pedestrians at the zebra- crossing. Impeding dangerous overpasses, especially for mopeds and bikes, of the bus stopped at the bus stop. Global increase of road safety (with low costs). Lectures at the IOWA STATE UNIVERSITY – April 2009

20. 20 Lectures at the IOWA STATE UNIVERSITY – April 2009 GAVINE (today)

21. 21 Lectures at the IOWA STATE UNIVERSITY – April 2009 “Oca Bianca” - Giardini DESIGN CATEGORY: 1.Removal of the pedestrian actuated signal (due to the actual poor pedestrians rate of flows). 2.Insertion of a new median traffic island to carry out: safe island for pedestrians crossing the road; left turns conflicts elimination; make a severe obstacle to bikers overpassing the bus where the bus stop is placed.

22. 22 Lectures at the IOWA STATE UNIVERSITY – April 2009 “Oca Bianca” - Giardini Previous layout Design layout

23. 23 Lectures at the IOWA STATE UNIVERSITY – April 2009 “Oca Bianca” - Giardini Via Lazzerini Via Corsinuovi Viale Ariosto

24. 24 VIA PAVESE Lectures at the IOWA STATE UNIVERSITY – April 2009

25. 25 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA PAVESE befor e after Inscribed circle diameter (no shoulders) 62,50 m 53,50 m Grassy central island radius 23,00 m 13,60 m Circulatory roadway width 7,5 m10,50 m Apron width---2,00 m Number of circulatory lanes 12 Number of entry lanes 1 per entry 2 per entry DESIGN CATEGORY: Improving the present roundabout via geometrical corrections related to the European standards. NEW GEOMETRY FEATURES:

26. 26 Lectures at the IOWA STATE UNIVERSITY – April 2009 Via Pavese Via Osmannoro Viale Ariosto Aerial view of the situation before works.

27. 27 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA PAVESE (design layout)

28. 28 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA PAVESE (superimposed) WHITE = actual RED = design

29. 29 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA PAVESE EXPECTED RESULTS*: DELAYS (weekday AM peak scenario ): Entry E[t] before E[t] design  (sec/veic) %% LoS Before LoS Design 1) Viale Ariosto (Ovest) 145- 9- 64%BA 2) Via Osmannoro 43- 1- 25%AA 3) Viale Ariosto (Est) 83,5- 4,5- 56%AA 4) Via Pavese > 609> - 50> - 90%FA (*) Values obtained by SETRA model for large roundabouts.

30. 30 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA PAVESE EXPECTED RESULTS*: QUEUES (weekday AM peak scenario ): (*) Values obtained by SETRA model for large roundabouts. EntryL 99 before L 99 design  (vehicles)  (metres) %% 1) Viale Ariosto (Ovest) 126- 6- 36- 50% 2) Via Osmannoro 43- 1- 6- 25% 3) Viale Ariosto (Est) 74- 3- 18- 43% 4) Via Pavese > 308> - 20> - 120> - 90%

31. 31 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA PAVESE (under construction)

32. 32 VIA NERUDA Lectures at the IOWA STATE UNIVERSITY – April 2009

33. 33 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA NERUDA (under construction) DESIGN CATEGORY: The signal controlled intersection is replaced with a large roundabout. GEOMETRY FEATURES: Inscribed circle diameter (no shoulders) 42,50 m Grassy central island radius 9,25 m Circulatory roadway width 9,50 m Apron width 2,00 m Number of circulatory lanes 2 Number of entry lanes 2 on 3 branches 1 on 1 branch

34. 34 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA NERUDA (before) Viale dei Mille Via Neruda Viale Ariosto

35. 35 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA NERUDA (design layout)

36. 36 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA NERUDA COMPARISON BETWEEN DELAYS* (weekday AM peak scenario ): EntryE[t] signal E[t] roundabout  (sec/veic) %% LoS signal LoS round 1) Viale Ariosto (Ovest) 44,12,5 - 41,6- 94% DA 2) Via Neruda 27,62,5 - 25,1- 91% CA 3) Viale Ariosto (Est) 10,33 - 7,3- 71% BA 4) Viale dei Mille 19,62,5 - 17,1- 87% BA (*) Values obtained by SETRA model (roundabout) and by HCS 5.2 (signalized intersection).

37. 37 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA NERUDA COMPARISON BETWEEN QUEUES* (weekday AM peak scenario ): (*) Values obtained by SETRA model (roundabout) and by HCS 5.2 (signalized intersection). EntryL 98 signal L 99 roundabout  (cars)  (metres) %% 1) Viale Ariosto (Ovest) 263 - 23- 138 - 88% 2) Via Neruda 113 - 8- 48 - 73% 3) Viale Ariosto (Est) 32 - 1- 6 - 33% 4) Viale dei Mille 83 - 5- 30 - 62%

38. 38 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA NERUDA (the road yard wallpaper)

39. 39 Lectures at the IOWA STATE UNIVERSITY – April 2009 VIA NERUDA (work in progress, April-July 2008)

40. 40 I MPROVING ROAD SAFETY AND OPERATIONS OF URBAN ARTERIALS: The study-case of Viale Ariosto in Sesto Fiorentino, Florence (Italy) Antonio Pratelli Department of Civil Engineering “Vie e Trasporti” University of Pisa (Italy) ISU – Iowa DOT Meeting 6th April 2009 Many thanks for your attention