question: What is unusual about I-19 ?
answer: the only Interstate highway that uses `` kilometer posts '' instead of `` mileposts ''
turker_answer: I-19 is unusual because it is the only Interstate highway that uses `` kilometer posts '' instead of `` mileposts . ''
rule-based: Unusual about I-19 is the only Interstate highway that uses `` kilometer posts '' instead of `` mileposts .