Which Opened has a Category of diesel light rail?
CREATE TABLE table_name_3 (opened INTEGER, category VARCHAR)
SELECT MAX(opened) FROM table_name_3 WHERE category = "diesel light rail"
### Context: CREATE TABLE table_name_3 (opened INTEGER, category VARCHAR) ### Question: Which Opened has a Category of diesel light rail? ### Answer: SELECT MAX(opened) FROM table_name_3 WHERE category = "diesel light rail"