What a bunch phooey. Just more peddling of flawed studies to promote increased taxation.
If you want to reduce congestion try the obvious. 1) Mixed zoning, allowing more residential and retail to be close together. So people have less distance to travel. 2) Raise speed limits where possible so people can get to their destinations faster. 3) Build for the future. Don't just add a lane or two, add six. 4) And yes trains, do help. The problem in the States is that we hardly have any. Only the major metro areas have any sort of adequate rail system and even they are fairly slow, limited and antiquated. Which brings me to my last point: 5) Consult with Elon Musk.
I'm sorry but you are simply way off base. When a road is expanded, it does temporarily shorten commute times and reduce traffic. But that makes the cheap land farther away from everything more desirable, causing people to move out further, increasing traffic. Those new suburbs require a massive infrastructure investment to install water, sewer, gas, electricity, etc. Not to mention building surface streets, schools, libraries, shopping centers, etc.
We've been building roads at a massive clip around the Dallas area, sprawling out over huge suburbs, many of which support mixed development (as does the city of Dallas itself). When I first moved here, the previous two lane highway had just been turned into a six lane toll road and there were no traffic jams, not even during rush hour. It's been 8 years and now we have stop and go traffic every day for about a 30 minute window and that window continues to grow larger.
If you think about the design of roads it should become clear why this happens... You have many on-ramps dumping cars into a fixed set of lanes. If, at any point, there are more cars that want to enter than there is room traffic must slow to accommodate them. In reality it happens before the road is full as people leave space for braking, etc. When that happens at any point, it creates a wave of slowed traffic that begins to ripple backwards from that point, meaning anywhere further backward that is close to capacity begins to jam up, making it even more difficult for new vehicles to enter the roadway, amplifying the wave even more.
Even if demand were 100% evenly spread out (which it never, never will be simply by the fact that brand new areas have empty fields or wooded lots - it takes time to build offices, start businesses, etc), the friction of merging & exiting the highway would eventually require more cars to exit than are entering, the exact opposite of rush hour conditions.
Building more lanes merely delays the inevitable; that's assuming you can, which in Dallas is impossible - most of the current roads (and 100% of the worst congested ones) would require tearing down skyscrapers or 100% tunneling / elevated highways because there is no more space.
Can you please explain how taxation plays into this? Are you implying that decreased investment in roads coupled with increased investment in public transit would increase taxation? What's your argument?
If you want to reduce congestion try the obvious. 1) Mixed zoning, allowing more residential and retail to be close together. So people have less distance to travel. 2) Raise speed limits where possible so people can get to their destinations faster. 3) Build for the future. Don't just add a lane or two, add six. 4) And yes trains, do help. The problem in the States is that we hardly have any. Only the major metro areas have any sort of adequate rail system and even they are fairly slow, limited and antiquated. Which brings me to my last point: 5) Consult with Elon Musk.