Paris has long had one of the world’s best public transport systems, but in recent years the city has made giant strides forward in reducing the impact of cars on the quality of the city – including the quality of its air. In 2016 cars were removed from the banks of the river Seine, opening up an amazing new public space for the city:
This Tuesday, Paris deputies submitted a report to Mayor Anne Hidalgo proposing a reduction of the speed limit on the Parisian Boulevard Périphérique, the 22-mile-long highway that encircles the central city, to 50 km/h (about 31 miles per hour). Cars and trucks on one of Europe’s most notoriously congested and polluted urban highways would not only be obliged to drive more slowly, they’d have less room to do it: The number of beltway lanes open to all traffic would also be slashed from eight to six. One lane will be reserved for public, emergency, and zero-emissions vehicles. The other one is to be devoted to trees.
It’s not that surprising to see Paris take another step towards improving the quality of their city, but perhaps what might be a bit surprising to some is a major likely benefit from these changes – reduced congestion.
Making a busy highway smaller and slower might seem like a counterintuitive means of defeating traffic in the U.S., where certain states and cities are working on widening, not culling, their traffic-clogged beltways. But during its peak hours, traffic is already moving at a very stately pace on Paris’ inner beltway: Average rush hour speeds are around 35 km/h. And many traffic experts say that lower speeds can improve fluidity and lower travel times by limiting the so-called accordion affect, in which vehicles accelerating and decelerating gradually create build-ups around junctions that turn into fully fledged jams. Driving more slowly, in some cases, can get you where you need to go faster.
It’s also likely that we will see the inverse of ‘induced traffic demand’, where removing vehicle capacity actually results in overall less traffic and less congestion. A classic case study of this recently was in Seattle, where there was a brief gap between the Alaskan Way Viaduct being closed and a new tunnel opening – yet traffic was actually better than usual during this time!
About 90,000 vehicles per day traveled the Alaskan Way Viaduct until it was closed on Jan. 11.
“The cars just disappeared,” he wrote. “Where did they all go?”
A spokesperson for the traffic data company Inrix told Gutman they “disappeared.”
Some people are walking and biking, preliminary city data shows. And some additional people took the bus and train. And a lot of people appear to be telecommuting.
As a result, traffic speeds haven’t been effected much by what everyone predicted would be gridlock.
Viadoom is looking more and more like another much-hyped “Carmageddon” that wasn’t. Time after time, cities anticipate crushing outcomes from the closures of key freeways — but the actual outcome is muted. We saw it with the closure of Los Angeles’s 405 freeway in 2011. And we saw it in more recently with the same highway in Seattle closed for two weeks of maintenance in 2016.
The changes in Paris will be great for safety, noise and air quality in this part of the city, as well as helping to reduce congestion:
That the Périphérique needs change is no secret. Since being completed in 1973, the city’s inner ring has developed a fearsome reputation for jams. It’s a formidable smog machine, too, pumping out >37 percent of all nitrous oxide emissions for the Greater Paris region. And with 156,000 people living within 200 meters of the road, it discharges these pollutants in a heavily populated band of territory…
…Slower traffic is quieter, too—Paris noise observatory Bruitparifreckons that holding vehicles to 50 km/h should reduce average levelsby a moderate but still significant two to three decibels. It is also notably safer, with slower speeds giving drivers more reaction time and lessening the force of collision impact. Past experience in Paris bears this out. In 2014, the Périphérique’s speed limit was reduced from 80 km/h to 70. This ten kilometer drop saw accidents fall by 15.5 percent in a single year.
Despite some backlash, it seems likely the changes will be approved in June.