The two sentences you see provided above are great ways to express to your listener that you have to use a train to get to a particular area. In the second sentence you will notice the word access. This means to enter a place or area. This word is appropriate for both formal and informal settings. They would make great additions to your vocabulary.
Native speakers will say like this: “We have to take a train to get there”.
There are lots of other ways to say it, but this one is the most accurate and most commonly used.
Here is an example on how to use this in a conversation:
A: Can you drive us to the airport?
B: I can't. We have to take a train to get there.
ネイティブスピーカーは次のように言います。
“We have to take a train to get there”
（電車に乗らないとそこには行けません）
他にもいろいろな言い方ができますが、これが最も正確で一般的です。
会話では以下のように使えます。
A: Can you drive us to the airport?
B: I can't. We have to take a train to get there.
↓
A: 空港まで車で送ってもらえますか。
B: 無理です。電車で行かないといけません。
You should use the train to arrive at that destination
The best way is by train or the only way is by train. We you "by" for transportation often: You go by foot , that means walking, or you can go by car or by bike or even by airplane. If the only way to get to the destination is by using the train you can say that one must or has to go by train, it's the only way. If the train is the best option, maybe its the fastest or the most direct, or the most comfortable you can suggest, You should use the train to get there or the best way is by train. Trains in many countries are very convenient and easy, many destinations are best by train.
"The best way is by train"（一番良いのは電車です）または、
"The only way is by train."（唯一の行き方は電車です）
交通手段には"by"をよく使います。"by foot"は「徒歩で」という意味です。
他にも、
"by car"（車で）
"by bike"（自転車で）
"by airplane"（飛行機で）
などと言います。
もし電車でしか目的の場所に行けないなら、「唯一の行き方（the only way）は電車である」という言い方ができます。
もし電車が、一番早いとか快適などの理由で最良の選択肢なら、以下のように提案できます。
You should use the train to get there（電車で言った方がいいです）
または、
The best way is by train.（一番良いのは電車です）
多くの国で電車は便利で使いやすいので、電車で行くのがベストなことが多いです。
日本 
インド 
アメリカ合衆国 
カナダ 
