New edition of Publication 46, Traffic Engineering Manual

Publication 46, Traffic Engineering Manual, has been revised on January 27, 2026. This update coincides with Pennsylvania's adoption of the Manual on Uniform Traffic Control Devices, 11th edition and includes changes proposed through Clearance Transmittals T-25-008 and T-25-012. 

Changes related to traffic signals in Publication 46 include:

• Incorporated several strike-off letters:
• 494-25-06, Traffic Signal System Toolbox (Publication 46 portion only)
• 494-25-05, Chapters 7 and 11
• 494-25-01, Chapter 12, Engineering Software
• 494-21-03, Chapters 1 and 4, Proprietary Equipment Approval Process
• Removes meanings of traffic signals in Chapter 4 since this repeats information already in the Vehicle Code and the MUTCD
• Removes traffic signal design-related content, which is proposed to be added to Publication 149 (see Clearance Transmittal T-25-001). Note: the policies in the 2012 edition of Publication 46 being relocated from Publication 46 to Publication 149 will remain in effect until the 2026 edition of Publication 149 is issued.
• Removed traffic signal maintenance-related content, which has been incorporated into the 2020 edition of Publication 191, Traffic Signal Maintenance Manual
• Updates to various hyperlinks and cross-references