Fun idea, and I like how it shows the passengers who are waiting etc.
Really could do with a fullscreen button and more zoom levels. I had to zoom in manually in the browser which at least made the controls big enough, but the world was still either way to small or way too large when I zoomed in, so it strained my eyes too much and I had to stop testing it.
Another quality of life suggestion would be to make the game remember the rotation of the previous road you placed, that way if you are placing a line of vertical roads you don't have to press rotate before placing the next one.
You could then make right clicking on a placed road delete it, which would make redesigning the road layouts a bit easier / more natural.
Overall though I really liked the vibe of the game. The music and sound effects work really well for this genre of game, and I liked the simplicity of the main menu design :)