Dallas Horseshoe ATM Design. Mike Holt, PE, PTOE Senior ITS/Traffic Engineering Manager

Transcription

1 Dallas Horseshoe ATM Design Mike Holt, PE, PTOE Senior ITS/Traffic Engineering Manager

2 Project Background $798 million Design-Build project south of Downtown Dallas Reconstruction of I-30/I-35E interchange and approaches across Trinity River Construction of new signature bridge over I-30 Started construction summer 2013; scheduled completion fall 2017

3 Project Team Texas DOT is owner Pegasus Link Constructors is D-B Joint Venture (Fluor Enterprises and Balfour Beatty Infrastructure) Parsons Brinckerhoff is lead design firm

4 Existing Conditions 460,000 ADT through interchange I-30/35E canyon depressed freeway section with 8 mainline lanes and auxiliary lanes Extensive existing signage Multiple lane closures and ramp detours

5 Existing Aerial Overview

6 Existing Conditions Photos

7 ATM Overview ATM proposed for value added project feature

8 ATM Overview Initial proposal included: Overhead lane control signals (LCS) Dynamic message signs Travel time signs Contractor negotiated DMS and TTS out of project scope PB proceeded with LCS design

9 Lane Control Signals 8 locations include: New overhead gantries (4) Existing bridge attachments (3) Existing overhead sign bridge attachment (1)

10 Lane Control Signals Skyline SlimLine LED Variable Message Signs 5 x 5 full color matrix 64 x 064 pixel layout 336S cabinet 2070 ATC controller Envoy DMS Central Control Software

11 Design Challenges Power Communications Structural attachments Sign visibility

12 Power 120/240 VAC 50 amp service to cabinet 20 amp service to each LCS Alpha Micro Secure 100 UPS

13 Power Challenges Need meter and disconnect for some cabinets Use existing ITS service for some cabinets Service points were not always close to LCS Prepared voltage drop calculations for service conductor sizing

14 Communications Wireless communications to temp. project TMC Sierra Wireless AirLink LS300 Gateway AntennaPlus Hockey Puck antenna Cat 5e cabling from cabinet to LCS

15 Communications Challenges Existing fiber network not accessible Cellular comm. to temporary TMC Cat 5e cabling limitations (<300 )

16 Communications Schematic

17 Structural Attachments Gantry Existing bridge Existing OH sign bridge Submitted customized structural details

18 Structural Details

19 Structural Details

20 Structural Details

21 Sign Visibility Reviewed available guidance documents for LCS visibility requirements: MUTCD Section 2L.03 Legibility and Visibility of Changeable Message Signs Offers guidance that CMS on roadways with speed limits of 55 mph or higher that messages should be legible from a minimum distance of 600 feet for nighttime conditions and 800 feet for normal daylight conditions.

22 Sign Visibility MUTCD Section 4D.12 Visibility, Aiming and Shielding of Signal Faces Offers guidance that traffic signal faces should be continuously visible to approaching traffic, from a point at least the minimum sight distance provided in Table 4D-2 85th-Percentile Speed Minimum Sight Distance 20 mph 175 feet 25 mph 215 feet 30 mph 270 feet 35 mph 325 feet 40 mph 390 feet 45 mph 460 feet 50 mph 540 feet 55 mph 625 feet

23 Sign Visibility MUTCD Section 4M.03 Design of Lane-Use Control Signals States the color of lane-use control signal installations shall be clearly visible for 2,300 feet at all times, unless otherwise physically obstructed

24 Sign Visibility Analysis Section 2L.03 applies to CMS (messages vs. LCS) Section 4D.12 addresses traffic signals (single color) Section 4M.03 most commonly applied to reversiblelane control and toll plaza lanes (more complex) Section 4D.12 (625 ) appears most appropriate for LCS visibility

25 LCS Deployment Recommendations LCS #1 (I-30 EB) proposed gantry LCS #2 (I-30 EB) proposed gantry LCS #3 (I-30 WB) existing bridge LCS #4 (I-30 WB) existing bridge LCS #5 (I-35E NB) proposed gantry LCS #6 (I-35E NB) existing bridge LCS #7 (I-35E SB) existing OH sign structure LCS #8 (I-35E SB) proposed gantry

26 Gantry Plan

27 Bridge Mount Plan

28 OSB Mount Plan

29 LCS Deployment

30 LCS Deployment

31 LCS Deployment

32 LCS Deployment

33 LCS Mounting

34 Current Progress

35 Current Progress