In other words, the merits, etc. of making detours are the consideration of the attitudes of the landowners whose property the line would cross, the convenience of other towns and villages, as well as connection with other railway lines.
There are merits and demerits to both your opinions so I'm not going to decide right away which to support.
Investing money in your home has some merit; when it is time to sell it you can get more money.
But in spite of the merits of being single, they do want to get married some day.
Carpets have the effect of a dust pocket, with merit of sucking up dust and stopping it flying around, but you can say that effect backfires.
Charms strike the sight, but merit wins the soul.
There's little merit in asking him for help.
There is little merit in this plan.
To do him justice, he is not without some merits.
Let's discuss the respective merits of the candidates.