Tech Tip
by Jack Mason, PTE

NWSVoyage™ FYLTA/Pedestrian Safety Module

This module was developed on contract with Oregon DOT and is to be added to the NWSVoyage™ 2070 program. The problem which is addressed has been of increasing concern to government and consulting traffic engineers and signal timers. Responding to ever increasing traffic demands a Flashing Yellow Left Turn Arrow (FYLTA) display was developed to provide a permissive period for left turns. This created a new conflict with pedestrians who are crossing the adjacent street in the crosswalk that the left turners go across. On high speed, 5-lane roadways the conversion from a protected left turn to a protected/permissive left turn has created unsafe maneuvers where the left turning vehicle doesn’t see the pedestrian, who is legally crossing in the crosswalk. We present this module as a graduated means to lessen the left turn & pedestrian conflict.

In general, regarding FYLTA operation it is good to think of it as 4 phase-pairs where the even phase is the through movement and the odd phase is the left turn. All of the various controller data entries  work on only one central problem: Relative to the start of the even phase green, when shall the FYLTA be displayed?

FYLTA/Ped Modes:

This module primarily addresses the common condition where the main street is Green and its left turn signals are in FYLTA. A pedestrian then arrives and pushes the button to cross the side street, in parallel with the main street. Currently, if the intersection is in Free or if it is in coordination and the ped permissive is open, the Walk will come up immediately with no change to the vehicle signals. With this new module there is a very significant change for the pedestrian. Pedestrians will have increased safety and also increased delay. They won’t get their Walk until one or both of the main street phases are terminated with a Yellow & Red and then come back to Green with a Walk but no FYLTA.
The following matrix shows the two major elements of this module.
1. How will the even phase of the pair be cleared?
2. What level of protection will the pedestrian receive?

Behavior Matrix for the mode of FYLTA/Ped Operation:

Note: To comply with MUTCD a 3 second buffer is incorporated into modes 2 & 4. This buffer will delay the start of the FYLTA after the end of FDW.

A more detailed description of modes 1 to 4 is below.

Mode 1: If an Even Phase Pedestrian Call is serviceable and the FYA is not active, the FYA will be delayed until the WALK is completed. If an Even Phase Pedestrian Call exists and the Even Phase/FYA is active, Red Revert will be initiated if a serviceable call does not exist across the barrier. If the FYA is active, then the Even Phase Pedestrian will be omitted. If Coordination is active, then Mode 3 will be used.

Mode 3: If an Even Phase Pedestrian Call is serviceable and the FYA is not active, the FYA will be delayed until the walk is completed. If an Even Phase Pedestrian Call exist and the FYA is active, a call across the barrier will be generated on the first non-omitted phase in the sequence if no serviceable call exist. If the FYA is active, then the Even Phase Pedestrian will be omitted.

[See NWS for description of Modes 2 and 4]

Programming the NOT PED Operation:

The 1st screen below is reached by Next-2-2-8-6. It is the 1st of 6 FYLTA screens. From there advance with the ‘A’ key to the 2nd screen below. The last line on this screen is the programming area for this feature. It is called NOT PED MODE. Place a value of 0 – 4 here for each of the FYLTA phase pairs which are used. If the additional Plans A – D are to be used advance to these screens with the ‘A’ key and enter the appropriate values for NOT PED MODE.

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Tech-Tips
by Ryan McKibben

“Ring out” the Field Outputs

When a new cabinet is installed at an intersection it is common practice for the electrician to “ring out” the field outputs to ensure continuity from the output terminals to the field devices. This is done by applying AC power to each output terminal and observing whether or not the associated field device turned on. While this process is adequate to identify errors in the field wiring, it does NOT prove continuity all the way back to the traffic signal controller.

NWS has provided a UNIQUE method for establishing continuity from the controller unit to the field devices called OUTPUT TESTING. The testing is performed through the menu of the controller while observing the field devices.

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Output Testing
by Ryan McKibben

When a new cabinet is installed at an intersection it is common practice for the electrician to “ring out” the field outputs to ensure continuity from the output terminals to the field devices. This is done by applying AC power to each output terminal and observing whether or not the associated field device turned on. While this process is adequate to identify errors in the field wiring, it does NOT prove continuity all the way back to the traffic signal controller.
NWS has provided a UNIQUE method for establishing continuity from the controller unit to the field devices called OUTPUT TESTING. The testing is performed through the menu of the controller while observing the field devices.

To use the Output Testing feature in NWSVoyage™, press the NEXT key, 3. Utilities, 7. Output Testing.  You’ll note that in the Utilities Programming Menu screen, under option 7 it states that the controller must be in Soft Flash operation in order to use the Output Testing feature.

To put the controller into Soft Flash operation – press the NEXT key, 2. Program Mode, 3. Coordination, 1. Coordination Modes.  The ‘<’ cursor should be to the right of ‘33’ in line with “FLASH”.  ‘33’ means that the Soft Flash mode can be activated via the Time Clock.  To use the Output Testing feature, we need to activate Soft Flash.  Change the ‘33’ to the value of ‘1’ and press the ENT or E key, or arrow down.  Now press the ‘*’ key and your screen should look like the one below.

Note: You need to have entrance and exit phases programmed for Soft Flash operation, or you will be prompted with a “See Help” message on the main run screen.  To program the entrance and exit phases, press the NEXT key, 2. Program Mode, 2. Controller, 5. Power-Up/Flash.  Cursor over to ENTR FL and EXIT FL and enter phase numbers for both R1 & R2 (ring 1 & 2).

Once you have entered the Soft Flash condition, now return to the Utilities Menu and select the Output Testing feature(NEXT, 3, 7).  The outputs will be displayed.  You can use the ‘A’ and ‘B’ keys to advance and go back through the different output screens.  To place an output to the street, cursor to the output you wish to turn on and place the AUX switch, on the front panel of the controller, to the ON position.  You will notice an ‘X’ appear under the output.  The ‘X’ indicates that you have turned on that output.  Check the output in the street to verify that it is in the ON condition.  Continue to do the same for all the outputs and you will have successfully tested your outputs in the field in a safe manner.