Comment Re:But is high speed rail a *good* public investme (Score 1) 419
yet the reality at least here in the UK is that many of the major road-building projects in recent years have been carried out precisely to simplify junctions or eliminate the need for some of them altogether
The ONLY way they can be avoided altogether is with flyovers/unders. And other than motorways, they are as rare as hens teeth. A miniscule fraction of a percent of junctions. And that's not changing.
Widening motorways doesn't create junctions, but it does pour ever more traffic onto the existing roundabouts that most motorway sliproads feed onto. With ever lengthening queues to get on and get off the motorways as a result.
You talk of projects to simplify junctions. And that's true. But equally more and more junctions with traffic lights or roundabouts are created. Every time theres a new housing estate, business park or supermarket built for starters. Plus wider busier roads mean more pelican crossings are created.
It is self-evident that if you build enough road then there will be enough space for a finite population of drivers and vehicles.
Common sense is commonly wrong. There is no finite population. The number of cars increases every year.
http://racfoundation.wordpress...
Nor is there an eventual limitation of the population figure, as the population rises every year too.
And you are thinking about it in the wrong way completely when you talk of "road space". The only thing space gives predictably you is car parks. The road system is a mostly 2D network. And as such it's limited by it's nodes. The bottlenecks are the junctions.