1. Toll roads - You can either choose to avoid, or choose to take. But I want to avoid toll roads when it will cost me > $x / saved hour. Or how about some optimization between fuel use and the value of my time? Paying $2 to save 30 minutes makes sense, buy not $15 to save 2 minutes. Where's the in-between setting/dial?
2. High-Occupancy Vehicle lanes. The highway may make a lot of sense with 2 people, but not while being a solo driver.
3. Traffic levels and when to wake up. I wish Waze could integrate with my alarm clock to wake me up extra early when major roads are closed, and I'd be majorly late for work without giving me an extra margin.
4. I'm not a trucker, nor an SUV driver, but something to account for high-height vehicles could be useful for many.