There were lots of bicycles left behind and they were a nuisance.
どちらも「放置自転車で溢れていて邪魔だった。」というニュアンスです。
1) There were so many abandoned bicycles in the way.
so many abandoned bicycles で「たくさんの放置自転車」と言えます。
in the way で「邪魔になって」
2) There were lots of bicycles left behind and they were a nuisance.
「たくさんの自転車が放置されていて迷惑だった。」
lots of bicycles left behind で「たくさんの自転車が放置されて」
nuisance で「迷惑・妨害」
ご参考になれば幸いです!