You can validate and tune by using a routeplanner to simulate how people will travel.
Starting from the existing road network you close streets or add new infrastructure. You model the new transport scheme by adding your own data to it.
We've built a routeplanner and some related tools that allow you to simulate how people will travel using the new transport scheme.
Share your work with the world and publish your transport scheme. This can be via a routeplanner or just using the API.