The study was in 1998 with a follow up review piece in 2002 https://nacto.org/wp-content/uploads/2015/04/disappearing_traffic_cairns.pdf

The study looked at dozens of sites across several countries. More recently, the Waltham Forest experience has reduced traffic overall, more people are walking and cycling plus modeled https://twitter.com/oneoval_/status/1283166275674480644

air quality assessments are showing improvements even on the main roads.

The problem we have here is the approach of the last 20+ years (if we're talking about the period since the study) has been to do very little to change the status quo. We have tried and failed to

"smooth" traffic flow by playing with traffic signals and we have spent a lot of money on traffic calming which has to a great extent been a failure. LTNs do produce good outcomes, even at a city-wide level (look at Ghent and Olso). The counter to complaints about the lack of

democracy we keep hearing about is interesting. If you go and read a local council's transport and planning policies, you'll find all sorts of good stuff about putting walking and cycling first, including policy documents which are really old. It's just that at long last,

councils are actually implementing those policies rather than them sitting on a shelf. Further to this, I don't ever remember being consulted on motor vehicles being given priority on the streets. This is hard for the "antis" to accept because they have become used to a way of

life where they can hop into their cars (especially for very short journeys - the data is there) without a second's thought for the impact they are having on their communities and especially the safety of children who have suffered from being chased off the streets and losing

their independence. Every time I see push back on this, I read the same old arguments (which are *never* backed up with data, just anecdote). Things have to change, we have allowed cars to dominate us for too long, despite being being useful tools.