A plan to widen Pacific Coast Highway has received the go-ahead from the California Transportation Commission. Two lanes will be added to the four existing between MacArthur Boulevard and Bay Shores Drive at a cost to the city of $8.1 million. Because of the widening, 14 homes in the De Anza Mobile Home Park will be purchased by the city and the residents relocated. Also, the highway will be striped to six lanes between Newport Boulevard and Dover Drive. Work on the project is scheduled to begin in 1986 and end in the fall of 1988.