真っ直ぐ and 直接: a straight path and going without a stopover
Separate a straight course from going directly to an office, without treating direct travel as proof that a road has no bends.
Following a straight line
真っ直ぐ, read まっすぐ, describes a straight course or shape. この道を真っ直ぐ進んでください。 asks someone to proceed straight along this road.
線を真っ直ぐ引きました。 says that someone drew a straight line. The word can describe a line’s shape as well as a course of movement.
Going without visiting an intermediate place
直接, read ちょくせつ, describes a method without an intermediate step. 駅から事務所へ直接行きました。 says that someone went directly from the station to the office.
家に寄らず、会場へ直接行きます。 says that someone will go directly to the venue without stopping at home. 家に寄らず specifies the omitted visit.
Road shape and intermediate visits are separate
道は曲がっていますが、店には寄らず、宿へ直接行きました。 says that the road was curved, but someone went directly to the lodging without visiting the shop. Curves do not require a stopover.
真っ直ぐ進んで、途中の店に寄りました。 says that someone proceeded straight and stopped at a shop along the way. A straight course does not rule out an intermediate visit.
Does 宿へ直接行きました。 establish that the road to the lodging was straight?
Show the answer and why
No. Here 直接 describes going without an intermediate visit. It does not specify the road’s shape.