Transport System is the sixth level of R-Type, an area that pilots will have to travel through between The Den and City in Ruins. This is a claustrophobic area, and large transports, known as Dops, will make some corridors completely impassible until they leave. There isn't a proper boss here, but instead pilots will have to contend with a horde of Dops.Sometimes it's called a Dops Rush (similar to the Zub Rush in the Gradius Series)
In the PC-Engine port of R-Type this stage does have a boss after beating the Dops Rush. It will forward to the screen to fight a boss. This playthrough, the boss from this stage is similar to the boss in the Real Stage 2 from Image Fight.