A tentative rebalancing scenario has been released for the 2017 Regional Freeway and Highway Program. According to MAG (Maricopa Association of Governments), the rebalancing program combined with current projects such as the I-10/Loop 303 interchange and the South Mountain/Loop 202 freeway represents a $5 billion program to meet current and future traffic demand.
Page 4 shows a map of all the projects, while page 5 shows the West Valley project: Adding lanes to Loop 101, SR-30, Loop 202/South Mountain, I-10 near Buckeye and Loop 101 north of Surprise.
You may also be interested in the ADOT 2017 Certification of Revenue and Costs.