Building bigger roads won’t make driving nicer. It will make traffic worse. That may seem counterintuitive. It’s also one of the most studied assertions of the last few decades in transport planning. A report from the University of Berkeley shows that for every 1% of extra highway capacity added, traffic volumes increase 0.9% in the longer term. When Houston, Texas expanded the Katy Freeway to 26 lanes at a cost of $2.9 billion, commute times went up. But you don’t have to look to the southern tip of a failed state for examples. Traffic volumes around the $1.4 billion Waterview Tunnel are roughly back to where they were before its construction.
This makes sense when you think about it for more than two seconds. When Apple releases new iPhones, people buy phones. When Hayden Donnell releases episodes of Get It To Te Papa, people watch Get It To Te Papa*. When governments build flash new roads, people drive. Even if the resulting traffic doesn’t clog up the motorways in question, it tends to funnel into suburban streets or smaller highways. The best we can hope for is to shift the bottleneck.
This is actually a fascinating look into the simplistic world view of someone like you. Motorways don’t simply end at the CBD like that, with everyone driving to the same place. They have a number of on and off ramps, with people getting off and on before and after the CBD.
Take the Taupo bypass, for example. Would you say not having heavy traffic chugging it’s way through the city centre has improved or worsened the situation?
I’d engage if you weren’t so inflammatory most of the time, as it stands, I just don’t have the energy.
You’ve argued yourself into a corner with your silly graphic, more like it.
It’s a well studied phenomenon now: more lanes in the long run do not improve traffic, and might also make them worse. There is nothing to dispute about that.
And the graphic portrays the problem perfectly.