But people don't drive randomly. They drive in predictable locations where the city, county and country have decided they should drive. Building all the homes over there, building all the offices over here, and having the whole population go from there to here at 8-9 in the morning and back at 5-6 in the evening was not an individual choice. The government (collectively, all parts of it) made those choices for us. And if you think it's an individual choice to commute at all - consider that you'd get arrested if you slept on the street outside of your office.
It’s worse than that because let’s say you have people commuting to their office from a suburb and let’s say it takes an hour. So you increase the road capacity so it takes 30 minutes instead. This just lets people from even farther away to take 60 minutes to commute. This means the employers have access to more employees who live farther away and pay less in their cost of living. This means more business can open and more employees can be hired for overall less money. Overall the problem is that any time you increase capacity you are just inviting more cars.
Imagine if we did not have congestion control in TCP and instead every time we got congestion we just upped the bandwidth. Do you think at some point our ability to increase capacity would outpace the demand for what is for the most part a free resource (I know neither roads nor network badwidth are free but the cost is amortized such that it “feels” free to the users)? Or do you think demand would grow as fast or faster than capacity?
The real answer is to reduce demand. You can do this by introducing something like congestion pricing: make it expensive to use the resource when demand is close to capacity. Or you add some form of congestion control. For example you could dynamically set speed limits on secondary roads and when the freeway traffic flow slows down you slow down cars as they try to get to the on ramp of the freeway. Or you could raise the price of gas by $1/gallon to discourage car use and use the revenue to build more public transit. You could charge single person car use fees. You could keep roads free but make parking downtown extremely expensive and use the proceeds to build more public transit. You could reduce speed limits in the cities to no more than 10 miles per hour and strictly enforce that; obviously this only works if you have much faster and higher speed public transit: imagine choosing between buying a car, car insurance, gas, and still taking 3x as long to get to where you want to go compared to buying a $50-100 monthly pass and using public transit.
