% capacity and % utilization are measures of congestion - not of demand. If your roads are only meeting 10% of latent demand and you double their capacity, guess what? They will be just as congested as before.
Leave it to "years of urban planning" to determine a proper solution is to make roads so poor that people decide not to use them.
> Leave it to "years of urban planning" to determine a proper solution is to make roads so poor that people decide not to use them.
What a weird level of snark. At least in NYC, demand is effectively infinite. Close to 2 million people commute into Manhattan every day, not counting commercial vehicle transportation. Building enough roads to satisfy all of those people is theoretically possible, but leads to plans like these:
I can't find it now, unfortunately, but there was a serious analysis done of what would be required to accommodate all of the potential demand for car transit into Manhattan, and it was insane how many bridges and roadways were required.
Thats' why you can't look purely at demand. As you make it easier to drive into a city, more people will opt to do so, thereby increasing both demand and capacity.
You even see this in US cities like Atlanta that are not islands, where increasing demand led to more and more road construction, which drove more and more people to live further and further outside the city, since they could just drive an extra 15-20 minutes each day. In the end, the only thing that capped demand for Atlanta was rising gas prices, making it more expensive to commute.
That's why you talk about capacity and utilization - demand is effectively infinite until other costs and considerations reduce demand.
NYC is the most extreme case. A good local example of is the San Mateo Bridge, at rush hour the San Mateo Bridge / 92 interchange backs up the 101 all the way to Woodside (several miles) but clears up after that. By the time they get around to expanding the bridge or adding another one (ha, when pigs fly) the demand will cause whatever the replacement is to be jammed as well as I would assume many more people would live in the East Bay which is cheaper.
I guess we would have to do something that requires effort like actually examine why people need to drive at all. The real problem is probably workers being denied the opportunity to live close to their places of employment due to predatory pricing and poor services downtown. But then we couldn't put the blame the average working stiff or use it as an excuse to decrease public works spending.
Leave it to "years of urban planning" to determine a proper solution is to make roads so poor that people decide not to use them.