When William Least Heat-Moon Heat wrote ‘Blue Highways: A Journey into America’ in 1979, he coined the term ‘blue highways’ because secondary highways on the old paper road maps were always printed in the blue. On the return from our holiday East Coast trip, Brennan suggested driving a ‘blue highway’ and since we relish road trips. but definitely dislike traveling on major interstates unless necessary, we opted to take his suggestion.