I am going to take some photographs myself of different buses but thought I would start with a couple of images from the web.
It must be decided whether the bus will be English or American (or neither of them) based, as this will also affect the location choices and the characters that ride upon it. Here are a few American ones.
I can rule out the school bus straight away because I do not want to limit the type and ages of the characters that ride the bus. I do however like the shape of the bus and its rounded roof.
The next image is also interesting as the colour breaks with convention, although it may look quite garish on screen.
The shape is also more square and it looks lower to the ground so this will affect the way it moves over the ground and also when it comes to a stop.
Things to consider:
- weight of the bus
- weight of the passengers
- how the bus moves around corners/ straight road
- speed the bus is travelling
- height to the ground and size of the wheels
This is going to get quite scientific!
Finally, I could not look into buses and leave out the classic red London bus. The difference between this and my other pictures is that it is a double decker, which could allow more character animation (with them climbing the stairs maybe drunk or looking shifty), and also more camera tracking shots from the different levels. The added section will also change the points listed above.