Here's the concrete arriving for the last section of the culvert roof. Note cyclists are advised not to pass down the left of the wagon.
This last section was quite large. After it was poured, the contractors stayed late to compact it.
The brickies built the stone wall of the parapet. This is much higher than the previous one, which had railings on it.
Maybe the idea is to dissuade people from chucking road signs in the river.