Ah, finally I've got back to this after a 2 1/2 month group project that took all my time up.
I'm just getting my head back into the code but am making progress already

This step shows the beginnings of a user interface and allows the user to set a number of vehicle types to be used in the animation. This basically means you can drop your own vehicles etc in, select them and then have them randomly generated on the road.
There are some additional controls (not activated yet) that will allow you to change the road style (left hand drive or right), how many lanes are in use and more.
The vehicle type chooser will have a percent amount or slider so that you can change the amount of certain types of vehicles - e.g, if its a busy road near a port then you would increase the truck vehicle frequency etc...

https://www.youtube.com/watch?v=bYuV79cQ-KA

Simon