In your own words what does ambiance mean?

Ambiance means the way I would describe a character an or some place I am at

Ambiance means mood of a place

The sentence needs a descriptor of exactly "what" will happen at gurley and marina. in this case, it is the light at the intersection turning green. in this case, the sentence could be rewritten as "the light at the intersection of gurley and montezuma will turn green exactly three seconds after the light at the intersection of gurley and marina."