【Indirect】 , 【circuitous】 ,  【roundabout】  are comparable when applied to ways, routes, or means with the meaning not leading by a straight path to a destination or goal.

【Indirect】 basically implies departure from the straight and short line between two points. In its extended uses  【indirect】 implies following a course that is not plain, obvious, explicit, or straightforward.

【Circuitous】 implies not only indirection but usually a winding and, because of its length, slow way or course.

【Roundabout】  may be used interchangeably with  【circuitous】 , but specifically it implies a following of a more or less circular or semicircular course from one point to another; the term more often than  【indirect】  or  【circuitous】 , especially in its extended use, implies deliberate, often blameworthy evasion or avoidance of the direct course or way.