I've never found the narrative that more roads were supposed to cause more congestion particularly convincing. If you fulfill demand, and then more demand springs up, then you fulfill that demand too. It's like with housing: the solution is to build more, not less.
Only in infrastructure construction do you see complaints that people take advantage of the provided service. In any other business where creating more product prompted superlinear demand, this would be seen as a marvelous opportunity.
There can exist a situation where the parameters limit possibilities.
For example, you can’t fit the world’s population in California and still have the same quality of life, even if you build 3 billion houses.
Same thing with roads, especially with regards to pedestrians and bicyclists. You simply can’t have big roads and big vehicles traveling at high speed in the same space as walking and bicycling people. Not to mention the exponential effects of spreading things out makes everything too far away, compounding the number of vehicles and need for lanes and so on and so forth.
Any elderly (or small child) person can’t cross a typical suburban 6 to 8 lane intersection. It takes a healthy adult 20+ seconds to cross some of these intersections.
The real solution is to create more desirable cities, walkable cities, and more economically productive cities so that all the demand isn’t in a few select locations. However, modern zoning and regulations don’t allow for the type of tight construction that allowed dense urban areas to come into existence in the first place.
Not to mention the politics of dealing with people who simultaneously want a single family house with a detached garage and front and back yard, but also want a walkable neighborhood where the kids can roam around outside with little risk of being hit by a pickup truck. These are conflicting demands and will never be satisfied.
The fewer people that drive, the less you have to expend on massive road projects and the better the experience for anyone who actually needs to drive. The whole bicycle infrastructure of a city like Amsterdam probably costs less than any single major highway, and the number of cars it eliminates from the road is massive. In my experience though, once a place has become car dependent, the attitude changes into one where alternative city design is almost impossible to contemplate. The assumption just becomes that adding a lane to a highway is the best course of action even though it doesn't really increase the flow that much at all.
Only in infrastructure construction do you see complaints that people take advantage of the provided service. In any other business where creating more product prompted superlinear demand, this would be seen as a marvelous opportunity.