daitairuuto to kousokusen wo kuraberu.

Here と means with in the sense of compare A with B.

A very common pattern is:

A と B を 比べる
= compare A and B / compare A with B

So in this sentence, 代替ルート and 高速船 are the two things being compared.

Because 代替ルート と 高速船 works together as one comparison set, and を marks that whole set as the object of 比べる.

So the structure is basically:

• 代替ルート と 高速船 = the two items
• を = marks them as the object
• 比べる = compare

This is normal Japanese grammar. You do not need を after both nouns.

Yes. That is also grammatical, and it is a very useful comparison.

• 代替ルート と 高速船 を 比べる
  = compare the alternative route and the high-speed boat/ferry

• 代替ルート を 高速船 と 比べる
  = compare the alternative route to/with the high-speed boat/ferry

The meaning is very similar, but the second version can make 代替ルート feel a little more like the main thing being examined.

Because Japanese is normally an SOV language: subject - object - verb.

So instead of English compare the alternative route and the high-speed ferry, Japanese puts the verb last:

• 代替ルートと高速船を = the things being compared
• 比べる = compare

This verb-final order is one of the most basic features of Japanese sentence structure.

Japanese often leaves out the subject when it is obvious from context.

So this sentence could mean things like:

• I compare the alternative route and the high-speed ferry
• Compare the alternative route and the high-speed ferry
• We will compare the alternative route and the high-speed ferry

The exact subject depends on the situation. Japanese very often omits information that English usually states directly.

The dictionary form is often used when a sentence is:

• a plain statement
• a heading or label
• an instruction in notes or lists
• an informal description of an action

So 代替ルートと高速船を比べる could sound like:

• a simple plain-form sentence
• a textbook example
• a note such as compare the alternative route and the high-speed ferry

If you wanted a polite sentence, you could say:

代替ルートと高速船を比べます。

Yes, 代替ルート is a noun compound.

• 代替 = alternative / substitute
• ルート = route

Together they form alternative route.

Japanese often combines nouns directly without の, especially in set compounds, technical terms, and borrowed-word combinations. So 代替ルート is completely natural.

高速船 literally means high-speed boat or high-speed vessel.

Depending on context, it may be translated as:

• high-speed ferry
• fast ferry
• speedboat or fast boat in some situations

So the best English translation depends on what kind of vessel the context is talking about. If the meaning shown to the learner is high-speed ferry, that is a very reasonable translation.

No. Normal Japanese writing usually does not use spaces between words.

So it would normally be written as:

代替ルートと高速船を比べる。

Spaces are often added only for learners, textbooks, or situations where someone wants to make the structure easier to see.

They are close, but not always identical in feel.

• 比べる is a very common everyday verb meaning to compare
• 比較する is a more formal or analytical word, often used in writing, reports, or academic contexts

So:

• 代替ルートと高速船を比べる sounds natural and straightforward
• 代替ルートと高速船を比較する sounds a bit more formal

Both can be correct, but 比べる is simpler and very common in basic Japanese.