How to Fix Traffic Forever
Wendover Productions thinks it has the answers to the world's traffic problems.
After the Katy Freeway between Houston and Katy, Texas, expanded to become the world's widest freeway—26 lanes across at its widest point—travel times actually increased by up to 55 percent. Adding more lanes actually made traffic worse rather than better. The video goes into detail as to why, but essentially the initial drop in traffic when the new lanes open convince more people to use the road who previously avoided it. This brings more traffic, which clogs up the road just as badly, or worse than before the expansion. Beyond a certain point, a small addition of cars adds a large amount of congestion.
Fortunately, the reverse of this is also true, which has led to many places implementing ramp meters. These slow down the flow of new traffic onto the highway, which helps traffic already on it keep moving smoothly. Another way to reduce the number of cars in congested areas is to charge a fee to drive there. London has had a congestion charge for years, and the video describes how Stockholm has significantly reduced traffic by doing something similar.
Another method Wendover Productions suggests is the use of roundabouts. Not only do these ease congestion by allowing traffic to keep moving slowly but continuously, they also eliminate the possibility of deadly head-on crashes since you never cross oncoming traffic. The side impacts at lower roundabout speeds are significantly less severe. But Wild in the Streets: The Boston Driver's Handbook describes the problem with roundabouts (or, as Bostonians call them, rotaries). One law says that traffic already in the intersection has the right-of-way. Another law says that the car on the right—the one entering the roundabout—also has the right-of-way. It's unclear who has the rightest way of all, so in true Massachusetts fashion everyone simply assumes it's them, everyone goes at the same time, and fender-bending hilarity ensues.
The final method discussed is the diverging diamond interchange, which replaces traditional on-ramps. Cars turning right onto a highway to do so the same way as normal. Then traffic crossing the highway temporarily swaps to the "wrong" side of the road, providing easy access for cars turning left to do so without cutting across oncoming traffic. Like the roundabout, this both eases congestion and eliminates the danger of head-on collisions.
Unfortunately, there is no magic bullet to eliminating traffic congestion. But given the experience of the Katy Freeway, it's clear that more creative solutions are needed than just throwing more lanes at the problem. Though none of these options will work in all circumstances, they're all worth considering in certain situations.