2019 sees the centenary of the ending of WW1 and 75 years since D;Day during WW2. The series has been placed with this, in mind.
The difficulty rating is a mix of the puzzle and the final location.
At each final there is enough room for a single car to pull over to allow room for a car to pass, if you are sensible.
The only hint for the series is at No1 for the puzzle
Now for the puzzle
Brentwood ABCD
Aldringham FGHJ
North F(A-B) C(G*H).(G+D)H(A+B) West (D-G)(C-F)(H+J) G(A-B).(G*H(D*H)(A*H+B)