That's about the same weight as the three to four commercial trucks.

这和三到四辆商用卡车的重量是一样的。

Parkways are freeways that do not allow large commercial business trucks and so forth.

。 公园大道是不允许大型商业卡车等通行的高速公路。

So, he's saying here that it is a more serious and important kind of music; it is not just something that you should listen to when you are watching a truck commercial, or advertisement.

所以， 他在这里说这是一种更严肃、更重要的音乐；这不仅仅是您在观看卡车商业广告或广告时应该听的东西。