Yeah, that part confused me too; the latency goes up, but the throughput stays the same. It looks like it's just a bad example, because the later example under

Yeah, that part confused me too; the latency goes up, but the throughput stays the same. It looks like it's just a bad example, because the later example under "Forming a Lock Convoy" shows better understanding of the problem's dynamics. A better initial example would be fast food or retail workers serving a single queue of customers.