My first influence map, based on William Heath Robinsons' work. There is already a sense of something happening in a city, a lot of steam, a lot of machinery and people frantically adding more to it, experimenting and pushing the boundaries of their own metropolis.
Second influence map is about the transportation of the people. Thankfully H. Robinson spent a lot of time on the subject - I think the Metropolis should be surrounded by water. Boats and submarines, and strange looking and over-sized bikes and vehicles on land.
The last influence map is concerned with the colour palette of the Metropolis. Since the overall feel is cartoony - the colours are blocky - with not a lot of shading involved and a welcoming palette of warm colours.