I'm bidding on your project because I have the necessary experience and ability to complete it.
As an undergraduate I worked with a professor of Physics creating various physics applets, I completed a game foundations certificate by creating and testing a game (as part of a team of 19 people) which used python and a graphics library called pygame. I also have experience using a graphics library called OpenGL. Suffisant to say I know how to work with python, graphics, and a little bit about physics.
From what you've posted, it looks like you want to copy the basic simulation you had referenced, and you would provide the specifics for the lane change and car following models.
I'd be able to create vehicle classes, as well as a street class which could both be modular. The biggest challenge here is the display of these objects - I could allow the model to scale to any size, but the optics might be a challenge. The other option is to put a limit of x lanes, and y vehicles. I'll work with you on that particular point.
Beyond that, the project looks interesting and fun, and I'd be excited to get to work on it.
Let me know if you'd like some clarification, or if you'd like me to get started.
I hope to hear from you soon,
Steven