Protected-Permitted Left Turn comparison

A PowerPoint presentation I made to illustrate the differences between various types of Protected/Permitted Left Turn controls.

Category:

Science & Technology

Tags:

• Traffic Engineering
• Traffic Signals

[DjPyro2010]

The way you solve this problem with the doghouse is to start the protected left turns first (red lights with green arrows on both sides) and then permissive left turns until perpendicular traffic needs to get through (green lights with no lit arrows on both sides

[ljthefro]

@DjPyro2010 Doing both protected left turns first does not address the issue of signal coordination where left turns are concerned. For good signal coordination along an arterial, lead-lag left turns (where one side gets the green left arrow at the beginning and the opposite side gets it at the end) are a must. Previously, before Dallas Phasing or FYA, the 5-section display would create the yellow trap when transitioning to the lagging left. The FYA is more accommodating in this regard.

[JKVIRALNETWORK]

How did you do that on power point?

[ljthefro]

A lot of complex custom animation.

[101moosefan]

They know have that 4 -section PPLT Display Flashing Yellow Arrow signal at the intersection near Champs and Costco on Burnhaven Dr. and W141st St. in Burnsville,MN