YOU SAID:

I had a friend in highschool who was fairly useless as a mode of transportation

INTO JAPANESE

高校時代の友人がいて、交通手段としてはかなり役に立たなかった

BACK INTO ENGLISH

I had a friend from high school and it was pretty useless as a means of transportation

INTO JAPANESE

高校時代からの友人がいて、交通手段としてはかなり役に立たなかった

BACK INTO ENGLISH

I had a friend from high school and it was not very helpful as a means of transportation

INTO JAPANESE

高校時代からの友人がおり、交通手段としてはあまり役に立たなかった

BACK INTO ENGLISH

I had friends from high school and was not very useful as a means of transportation

INTO JAPANESE

高校時代からの友人がおり、交通手段としてはあまり役に立たなかった

BACK INTO ENGLISH

I had friends from high school and was not very useful as a means of transportation