Category C (Class 2) LGV / HGV training runs around Ipswich, Suffolk and uses the DVSA Test Centre in Ipswich. C is the category that allows you to drive a rigid vehicle over 3,500kg.
USB 2.0 is much faster than the DVD data rate. DVD 1x (slowest) write speed is 1.39MB/s. DVD 24x (fastest) write speed is 33.24MB/s. USB 2.0 write speed is up to 35MB/s. A 24x DVD max is about 32MB/s while USB2 max is about 60MB/s.
The root of the faster performance lies in how quickly SSDs and HDDs can access and move data: SSDs have no physical tracks or sectors and thus no physical seek limits. The SSD can reach memory addresses much faster than the HDD can move its heads. The distinction is unavoidable given the nature of IO.