编辑以下段落，以将Passive Voice转换为Active Voice。
"由于城市规划上的错误，路边停车往往受到限制，有时候非常困难。"

Due to errors in urban planning, restrictions on roadside parking are often imposed, making it sometimes very difficult. 

(Active: Errors in urban planning often impose restrictions on roadside parking, making it sometimes very difficult.)