Final answer:
The signal indicating the alternate route would PROBABLY display the aspect (27-109), which typically consists of a green arrow pointing to the left or right.
Step-by-step explanation:
The signal indicating the alternate route would PROBABLY display the aspect (27-109).
In the context of traffic signals, the term 'aspect' refers to the pattern of lights displayed by the signal. The number in parentheses represents the specific aspect displayed by the signal. In this case, aspect (27-109) would indicate the alternate route.
For example, aspect (27-109) may consist of a green arrow pointing to the left or right, indicating that drivers should take the alternate route in that direction.