Comment by cbhl

I actually think the Viva system in York Region, Ontario, Canada is a great model for this.

Highway 7 started as a car-only multi-lane highway. They took a multi-phase approach to building out a light-rail system. The first phase was adding bus rapid transit, increasing fares, and increasing density of new construction. The second phase was adding dedicated bus lanes and light-rail-ready stations. The final phase will be to add tracks and trains on top of the road.