How to count trains per day?

Question

In this sentence, how does one read the counters?

1日あたり16本運行しています
There are 16 trains per day.
https://www.fnn.jp/articles/417130

I found several answers, such as...

• 1日【にち】あたり16本【ほん】運行【うんこう】しています (https://www.jcinfo.net/en/tools/kana)

• 1 にち-あたり16-ぽん うんこう して います (https://j-talk.com/)

• 日あたり【ひあたり】(2) (日当たり, 日当り, 日当 only) per day (http://wwwjdic.biz/)

My best guess is

• [1日]【いちひ】あたり[16本]【じゅうろっぽん】運行【うんこう】しています

Answer 1

• This 1日 is read いちにち. Other readings (ついたち, いちじつ, いっぴ, etc) are incorrect. Although there is a phrase ひあたり ("per day"), this is an independent phrase that cannot be used with a number like "1".
• As for 16本, you can read it either as じゅうろっぽん or じゅうろくほん. Both sound natural, and I don't know which is better.