Traffic Signal Design Guidelines

TRAFFIC SIGNAL DESIGN GUIDELINES

Revision: 2.0
September 2010

Document Revision History

DATE | REV. | SPCR(s) | SECTIONS | DESCRIPTION | 11/2000 | Rev. 1 | | | Initial release of document | 05/2003 | Rev. 1.1 | | | Draft of first major update | 11/2003 | Rev. 1.2 | | | Final of first major update | 7/2010 | Rev. 2.0 | | | Major update |

GEORGIA DEPARTMENT OF TRANSPORTATION
TRAFFIC SIGNAL DESIGN GUIDELINES

TABLE OF CONTENTS
Section 1 1
INTRODUCTION 1
1.1 Applicable Standards and Specifications 1
Section 2 1
GENERAL INFORMATION 1
2.1 General Signal Plan Presentation 1
2.2 List of Materials/Pay Items 2
2.3 Miscellaneous Elements and Special Situations 2
Section 3 1
DESIGN STANDARDS 1
3.1 Traffic Signal (Concurrent) Phasing 1
3.1.1 Left-Turn Phasing 2
3.1.2 Split Phasing 2
3.1.3 Preemption 3
3.1.3.1 Railroad Preemption 3
3.1.3.2 Blank-Out Signs 4
3.1.3.3 Emergency Vehicle Preemption 6
3.2 Vehicular Signals 6
3.2.1 Display 7
3.2.2 Mounting 7
3.2.3 Position 7
3.2.3.1 Head Placement Guidelines 7
3.2.3.2 Guidelines for Channelized Left-Turn Lanes with Wide Medians 8
3.2.4 Signal Head Equipment 10
3.3 Pedestrian Signals and Poles 10
3.3.1 Pedestrian Considerations 10
3.3.2 Pedestrian Signal Heads 11
3.3.3 Curb Ramps 11
3.3.4 Pedestrian Refuge Islands 11
3.3.5 Poles 12
3.3.6 Signs 12
3.4 Traffic Signal Poles 14
3.4.1 Pole Placement 14
3.4.2 Strain Poles 14
3.4.3 Timber Poles 14
3.4.4 Joint Use Poles 15
3.5 Span Wire Configurations 15
3.6 Mast Arm Configurations 15
3.7 Cabinet Assemblies 16
3.7.1 Controller Equipment and Software 16
3.7. 2 Cabinet and Cabinet Bases 16
3.7.2.1 Input File 17
3.7.3 Battery Backup (Definitions and Reasons Why) 18
3.7.4 Modems 18
3.7.5 Cabinet Placement 20
3.7.6 Power Disconnect 20
3.8 Vehicle Detection 21
3.8.1 Detector Modes 21
3.8.1.1 Presence Detectors 21
3.8.1.2 Pulse Detectors (Volume Density/Setback Detectors) 22