[sumo-user] Traffic Light State

[Nick S. <nic...@gm...>]

Hey there still a relatively new user. I am writing a program that sends
out an emergency vehicle to a crash site where certain driving policy
changes are made on the emergency vehicles' route. One of these is to set
al traffic lights it reaches green.

At first I attempted to change it using the get/setPhase() methods which
proved unsuccessful:

def setNextLight(ambulanceID) :
tral = getNextLight(ambulanceID)
if tral:
print "Next light is : ", tral
if traci.trafficlights.getPhase(tral)!=4 :
traci.trafficlights.setPhase(tral, 4) #if not green set green
print "traffic light set to green"

I can't remember why I thought setting it to 4 would make it green I wrote
this in my first two weeks of using Sumo, I tried to fix it by using the
setRedYellowGreenState() method instead but this caused invalid phase
length exceptions (I assume because it interrupted a current phase to make
the change).

So my question is how do I make this function work (getNextLight() is a
 function I wrote myself, it seems to work fine).

Thank you!

Nick