"Curious about what Portland's traffic and its growing signal system might look like 100 years from now, I recently asked Peter Koonce, the city's chief traffic signal engineer, to take us into the future. Here's how he responded in an email:"
I am not a futurist (yes, that's a title), but I played one when writing a Strategic Highway Research Program Project proposal back in my consulting days. There are so many scenarios, it is really hard to imagine and state what's actually possible. So, in order to talk around the question, it is best to describe various possible scenarios.
There's what I would call the pessimistic view that suggests that we'll have the same constraints in the future because the public sector will be financially constrained and afraid to innovate and adopt new technologies.
There's an optimistic perspective that offers that technology will change everything and what we have today will be obsolete. Driverless cars and "Connected Vehicle" concepts will be the new normal. Technology could eliminate the need for much of the travel that we have to make today including the typical work commute.Amazon.com is a good example of the impact of technology on shopping trips, video conferencing for business should continue to evolve and become more useful, and the population will change albeit slowly as we age more gracefully (if that trend continues).
At the end of the day, the cost of energy (think Peak Oil and climate change) will likely play a large role in this and that's hard to pin down since you're asking a transportation professional, so that will be an influence.