The driver ahead is a menace to other road users!!
You may just state that the car is dawdling or going slowly, or, as the number of cars affected grows, you may then state that a traffic jam is being caused. If you find yourself getting annoyed with the slow progress and the seemingly illogical pattern of driving of the car ahead, you may describe that driver as 'a menace to other road users!'
To dawdle - delay, procrastinate, lag, loiter, dawdle. This means to move or act slowly so as to fall behind or delay.
ただ単にその車は "dawdling"（ぐずぐずする）又は "going slowly"（ゆっくり進む）と言う事が出来ます。
または、その車によって影響を受けている車の台数、
その車によって交通渋滞が起きている事を言い表すことが出来ます。
前の車のノロノロ運転や、不合理な運転の仕方にイライラしてきたらその車の事を次のように言い表すことが出来ます。
'a menace to other road users!'
（道路使用者の脅威）
To dawdle （ぐずぐずする、ノロノロする）
- 遅らせたり、ノロノロしたり、ぐずぐずしたりすることを意味します。
There are a load of cars backed up because of this slow driver.
When cars are backed up, it means they are all bunched together and moving very slowly like a traffic jam. This happens when a car is driving too slow and the cars behind catch up and then have to slow down to avoid a collision.
"The road is backed up with cars."
cars are backed upというのは、車がまとまって渋滞のように非常にゆっくりと動くことを意味します。これは、遅すぎる車があり、それに追いついた車が衝突を避けるために減速しなければならないときに発生します。
【例文】
"The road is backed up with cars."（道が車で渋滞しています）
The driver in front of me is causing a traffic jam.
By saying that a driver is "slowing down traffic" you are implying that he/she is causing a traffic jam and that the cars behind him/her would then also be driving slowly.
slowing down trafficと言う事によってそのゆっくりな車が交通渋滞を引き起こしていて後ろの車がゆっくり運転になることをほのめかすことが出来ます。
You can say that 'The car ahead of me is driving very slowly'. The slow driver could cause a traffic jam because he is driving too slowly!You could also say that 'Other cars in the same lane are backing up behind the slow car because the driver is driving far too slowly'.
次のように表現することが出来ます。
'The car ahead of me is driving very slowly'.
（前の車のスピードが遅い）
あんまり遅すぎる"slow driver" （遅い運転）は交通渋滞を引き起こします。
また、次のようにも表現することが出来ます。
'Other cars in the same lane are backing up behind the slow car because the driver is driving far too slowly'.
（あの車遅すぎるから同じレーンの車が渋滞してる）
The driver ahead of me is causing a traffic jam with his slow driving.
Native speakers will say like this: “The driver ahead of me is causing a traffic jam with his slow driving”.
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: Finaly, you're home. What took you so long?
B: The driver ahead of me was causing a traffic jam with his slow driving.
ネイティブスピーカーなら、このように言うでしょう：
“The driver ahead of me is causing a traffic jam with his slow driving”.
（前の人の運転が遅くて渋滞が起きている）
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。
会話で使うと次のようになります：
A: Finaly, you're home. What took you so long?
［訳］やっと帰ってきたわね。なんでこんなに時間かかったの？
B: The driver ahead of me was causing a traffic jam with his slow driving.
［訳］私の前を走ってる車が遅すぎて渋滞してたのよ
There is a traffic jam starting because the car in front of me is driving really slow.
The car in front of me is driving very slow so cars are backing up behind me.
"There is a traffic jam starting because the car in front of me is driving really slow." This is a way of explaining that the car in front of you is driving slow so there is a traffic jam forming.
"The car in front of me is driving very slow so cars are backing up behind me. " This is another way of explaining a traffic am is starting due to the car in front of you driving very slow.
"There is a traffic jam starting because the car in front of me is driving really slow." という例文について
この文は、あなたの前の車が遅いせいで、後ろに渋滞が起こっていることを説明しています。
"The car in front of me is driving very slow so cars are backing up behind me. " という例文について
この文は、上記と同じ意味の別の言い方です。
The car in front is causing a build up of traffic as it's going so slow
The driver in front is causing a traffic jam
A traffic jam is when cars there are alot of cars that can't really move or are moving very slowly
You could simply say 'The car in front is going slow' although this doesn't really explain it well so you would be better to say 'The car in front is causing a build up of traffic/traffic jam as it's going so slow' this explains exactly what is happening although a simpler way is 'The driver in front is causing a traffic jam'
traffic jam'（交通渋滞）は、車が混雑してほとんど動かないこといいます。
シンプルに、
'The car in front is going slow'（前の車が遅い）
と言えます。ただ、これだとあまりうまく説明できていません。
こちらの言い方がいいと思います：
'The car in front is causing a build up of traffic/traffic jam as it's going so slow'（前の車が遅いので、渋滞になってしまっています）
これで状況を正確に説明できます。
よりシンプルに、
'The driver in front is causing a traffic jam'（前の車が渋滞を起こしています）
と言うこともできます。
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