Meaning of いかにもついでに~ような

Question

I found this sentence in a book:

いかにもついでに掘ったような細い道を無視し、放置されたライトが多くぶら下がってる方向を選んだり、と自分なりに工夫しながら進む

I think I kind of understand it: something like "Ignoring the narrow dug paths, I chose the direction in which many abandoned lights hung, and proceeded while devising my own way", but I'm not sure about what いかにもついでに and ような means in this context.

I think those two parts, いかにもついでに and ような, are not linked in a single form. As for いかにもついでに, I know the single words いかにも and ついでに, but I'm not really sure about what they mean in this case.

For context, the character is trying to find her way to the surface, and after finding a service tunnel and opening it by thawing some ice, there is not sign she dug any passage; there is not much added by the text, as far as I understand, since one chapter ended with the character entering the tunnel, and the next started with:

右、右、左、上、左ちょっと下って、また上へ。

迷路のような入り組んだトンネルを私は黙々と進んでいく。

followed by the sentence I'm unsure about.

All in all, my guess is:

• the paths in questions aren't dug by the character, but they are already there
• いかにも is linked to 無視, meaning she is completely ignoring those paths; or maybe is linked to ついでに掘った, reinforcing it
• ついでに is linked to 掘った, and adds a sense like those paths were dug incidentally, while digging the main path
• ような means "ignoring the path that looked like they were dug incidentally", so is how the character perceives them, rather than an objective fact

but I'm not really sure.

Answer 1

You should parse it this way.

［いかにも［ついでに掘った］ような］［細い道］

ついでに indeed modifies 掘った. Digging those narrow paths was (apparently) not the main purpose of whoever dug them. I have never known how to accurately translate ついでに. I am not sure if "incidentally" conveys its nuances completely.

ついでに掘った細い道 would mean that the speaker knows for a fact that the paths were dug in such a manner.

ような indicates that it is the speaker's perception that the paths are such.

いかにも further adds the sense that that perception is obvious from the appearance of the paths.

So the character ignored narrow paths that obviously looked like they had been dug only as secondary purposes of whoever dug all those tunnels.

Answer 2

You are pretty close.

This いかにも is defined in Wiktionary as:

見えたり感じられたりするさまを強調する。推量や様態、比喩の明確化。まさしく、みるからに（そのようだ）。

It should be easier to tease out a better sense of its usage with my highlighted keywords. Namely, this usage stresses that how something looks/sounds/smells to you or how you perceive something is true/just like that. If you look it up in a Japanese-English dictionary, you'll probably only get "truly", "really", but I think with just that the actual usage eludes you.

The important thing here is this usage of いかにも latches onto a word that describes perception, making the perception more concrete, and affirmatively reinforcing that perception.

あいつっていかにも優しそうだな！
That guy does seem nice!

いかにもロスらしい雰囲気
very L.A.-ish ambience

It's very perceptive of you to use the word "reinforce". Good job. Your second guess is a good one. いかにも adverbially modifies ついでに掘ったような細い道: "what appear to be incidentally dug narrow paths" or "seemingly incidentally dug narrow paths".

いかにもついでに掘ったような細い道
narrow paths that truly look like they were incidentally dug