One of the four woodblock prints I bought. This one shows a procession that always preceded the arrival of a daimyo, or provincial governor. All daimyo were required to live in Edo for six months of the year. Their families were required to live in Edo full-time. This was a ploy by the Shogun to keep the daimyo on a short leash. So when the daimyo came into town, he didn't just have a duffel bag over his shoulder.
I don't know for sure, but there's a good possibility that they're crossing Nihombashi ("Japan Bridge").