I MPROVING ROAD SAFETY AND OPERATIONS OF URBAN ARTERIALS:

1. CE552 Highway Safety Meeting 7th April 2009 IMPROVING 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)

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

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

4. VIALE ARIOSTO Lectures at the IOWA STATE UNIVERSITY – April 2009 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%

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

6. THE “ARIOSTO” PROJECT • System approach design: the project has been extended to the arterial in its whole. Lectures at the IOWA STATE UNIVERSITY – April 2009 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). • We show some interestingdesign items, such as: • - Querciola and Pavese (roundabout functional improvement); • - Gavine and Oca Bianca (traffic calming device); • - Neruda (conversion from signal to roundabout);

7. THE “ARIOSTO”PROJECT(2) • We show some interestingdesign 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. VIA QUERCIOLA Lectures at the IOWA STATE UNIVERSITY – April 2009

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

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

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

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

13. Entry direction: Present state Design state Difference % 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 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 mt 99%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 % VIA QUERCIOLA EXPECTED RESULTS* (AM peak scenario): Lectures at the IOWA STATE UNIVERSITY – April 2009 (*) Values obtained by SETRA model for large roundabouts.

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

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

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

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

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. 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. Lectures at the IOWA STATE UNIVERSITY – April 2009 Global increase of road safety (with low costs).

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

21. “Oca Bianca” - Giardini • DESIGN CATEGORY: • Removal of the pedestrian actuated signal (due to the actual poor pedestrians rate of flows). • 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. Lectures at the IOWA STATE UNIVERSITY – April 2009

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

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

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

25. VIA PAVESE DESIGN CATEGORY: Improving the present roundabout via geometrical corrections related to the European standards. NEW GEOMETRY FEATURES: Lectures at the IOWA STATE UNIVERSITY – April 2009

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

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

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

29. VIA PAVESE EXPECTED RESULTS*: DELAYS (weekdayAM peak scenario ): Lectures at the IOWA STATE UNIVERSITY – April 2009 (*) Values obtained by SETRA model for large roundabouts.

30. VIA PAVESE EXPECTED RESULTS*: QUEUES (weekdayAM peak scenario ): Lectures at the IOWA STATE UNIVERSITY – April 2009 (*) Values obtained by SETRA model for large roundabouts.

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

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

33. VIA NERUDA (under construction) DESIGN CATEGORY: The signal controlled intersection is replaced with a large roundabout. GEOMETRY FEATURES: Lectures at the IOWA STATE UNIVERSITY – April 2009

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

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

36. VIA NERUDA COMPARISON BETWEEN DELAYS* (weekday AM peak scenario): Lectures at the IOWA STATE UNIVERSITY – April 2009 (*) Values obtained by SETRA model (roundabout) and by HCS 5.2 (signalized intersection).

37. VIA NERUDA COMPARISON BETWEEN QUEUES* (weekday AM peak scenario): Lectures at the IOWA STATE UNIVERSITY – April 2009 (*) Values obtained by SETRA model (roundabout) and by HCS 5.2 (signalized intersection).

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

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

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