The initial value of 1,400 represents the distance from your starting point to your final destination.
In the equation \( f(x) = -350x + 1,400 \), when \( x = 0 \) (the start of your journey), the function \( f(0) = 1,400 \). This indicates that at the beginning of your trip, you are 1,400 miles away from your final destination.