A vehicle's signals are encoded in an integer, each by one bit, encoding whether the according signal/... is on or off. Most signals are rather meant to be used by an external application. However, a few signals are computed in each step.
The following signals are computed in each time step. The value set via TraCI is only retained for the current time step.
- VEH_SIGNAL_BRAKELIGHT: The brake light is set whenever the vehicle is standing (not stopped) or when the vehicle decelerates beyond a threshold value. The signal value is used by the vehicles when trying to avoid jamming on an intersection.
- VEH_SIGNAL_BLINKER_RIGHT and VEH_SIGNAL_BLINKER_LEFT:
The blinker is activated in either of the following conditions
- The vehicle is about to take a turn at an intersection (activated 7 seconds before reaching the intersection)
- Either of the continuous lane-change models is active
- A desired lane change cannot be executed due to neighboring vehicles.
- a vehicle is about to stop for parking
- the vehicle is stopped on a lane that is not the rightmost usable lane (emergency blinkers on both sides are active)
- VEH_SIGNAL_EMERGENCY_BLUE: when switched on, a blinking blue light is shown in the GUI for vehicles with vClass="emergency" and shapeClass="emergency"
The following table shows the defined signals.
Sending a negative signal value immediately resets all signals to their computed values.