This is the 8207th most frequent Japanese word.
差し掛かっ
"差し掛かっ" means "to approach" or "to reach (a point or place)."
Here, "差し掛かった" indicates approaching or arriving at a certain location, namely the bridge.
橋に差し掛かって、車が急に止まりました。
As we arrived at the bridge, the car suddenly stopped.
Here, "差し掛かった" is used to express that a situation or event, specifically the season, is nearing or beginning to happen.
秋が差し掛かってきました。
Autumn is approaching.
In this case, "差し掛かった" describes the action of reaching or arriving at a particular location, specifically turning a corner.