I think that there are more non-reserved seats available during this time.
"この時間は自由席の方が空いてると思うよ"
- I think that there are more non-reserved seats available during this time.
- There are probably more non-reserved seats around this time.
新幹線の切符を買う際、時間帯によっては指定席より自由席の方が空いている時があるので指定席より自由席を買って乗った方がいいかもよ
- When you buy a ticket for the shinkansen, depending on the time, there might be more non-reserved seats than reserved ones so you may want to get a non-reserved seat.
There aren't as many people in the non-reserved cars around this time compared to the reserved cars.
There are fewer people in the non-reserved cars than the reserved cars around this time.
この場合、次のような言い方ができます。
ーThere aren't as many people in the non-reserved cars at this time of the day compared to the reserved cars.
「この時間帯は、指定席車両と比べて、自由席車両にはあまり人がいない」＝「指定席より自由席の方が空いている」
ーThere are fewer people in the non-reserved cars than the reserved cars around this time.
「この時間は、指定席車両より自由席車両の方が人が少ない」＝「指定席より自由席の方が空いている」
the non-reserved cars「自由席車両」
the reserved cars「指定席車両」
ご参考まで！
アメリカ合衆国 
カナダ 
