NYCs new congestion pricing scheme under threat. But what impact has this approach to traffic management had in other cities? A Congestion Pricing sign on Park Avenue in New York, US, on Friday, Jan. 3, 2025. The fate of NYC ... [+] new scheme hangs in the balance after the U.S. Transportation Secretary Sean Duffy announced that the Federal Highway Administration had "terminated approval" for it. Photographer: Michael Nagle/Bloomberg 2025 Bloomberg Finance LPOn 5 January 2025, New York became the first city in the U.S. to introduce a congestion pricing zone, in an effort to ease traffic in central areas, and to raise funds for the city's public transit system. The scheme requires drivers to a pay a fee for their vehicle to access Manhattan (below 60th Street), with the fee set higher for larger vehicles and for travel during peak times, and lower for smaller vehicles and for travel during off-peak times.Within the schemes first week, traffic had fallen by 7.5%, with 273,000 fewer cars entering Manhattans central business district, and travel times on inbound river crossings had been cut by more than a third, leading to faster bus journeys. By the end of January, tolls from the congestion pricing program had generated $48.66 million in revenue, putting it on-track to meet the Metropolitan Transportation Authoritys first year target of $500 million. So far, so successful.And then, on 19 February, the U.S. Transportation Secretary Sean Duffy announced that the Federal Highway Administration had "terminated approval" of New York City's congestion pricing scheme, calling it backwards and unfair. The next day, the official White House account tweeted an image of President Donald Trump, in which he likened himself to a king saving the city.In response, New York Governor Kathy Hochul said Im here to say New York hasnt labored under a king in over 250 years. And we sure as hell are not going to start now. The MTA filed a lawsuit in Manhattan federal court challenging the decision, and theyve since been joined in that effort by environmental groups and transit advocates.At the time of writing ten days before the termination date of 21 March set by the Trump administration no decision has yet been made on the lawsuit. The fate of NYCs scheme hangs in the balance.But are congesting pricing programs really worth pursuing? Lets look at some of the impacts that theyve had in other cities around the world.A local bus passes an ULEZ (Ultra Low Emission Zone) sign on the South Circular at Tulse Hill, on ... [+] 21st July 2023, in London, England. The scheme has been extended since it was first introduced, and now incorporates all London boroughs (Photo by Richard Baker / In Pictures via Getty Images)In Pictures via Getty ImagesWhats happening elsewhere?Urban congestion pricing has existed for 50 years Singapore was the first place in the world to adopt it, but schemes have since been rolled out in cities including Milan, Stockholm and London. Each of these cities use their own slightly different zoning schemes and pricing mechanisms, but ultimately, all are trying to reduce the number of cars and other vehicles in specific areas.Economists argue about the details of road- or zone-based tolls, e.g. around how much to charge, and how to reduce the cost of running a pricing scheme but most agree that such schemes have a net positive effect on society. Congestion pricing is often very unpopular when first introduced, and is (sometimes rightly) viewed as profitable but inequitable. Ultimately, the key to making congestion pricing zones both fair and popular is through the provision of alternative modes of transport beyond private vehicles frequent and low-cost mass transit, and safe cycleways and footpaths. On that front, some cities are more successful than others.Londons pricing zones are the most extensive and the most well-known. The city has two overlapping schemes that manage the type and quantity of vehicles that can drive on its roads. Ultra-low-emission zones (ULEZs) are areas in which vehicles that exceed specific exhaust emission standards are either banned entirely, or are required to pay a toll. As of 2019, the ULEZ covers all London boroughs; an area measuring 1,500 km2, which is home to nine million people. Theres also a smaller Congestion Charge Zone (CCZ) in central areas, which, like NYC, charges all vehicles to enter during specific times.The Stockholm congestion tax was made permanent in 2007, after being discussed for close to two ... [+] decades. (Photo by JOKER / Paul Eckenroth/ullstein bild via Getty Images)ullstein bild via Getty ImagesDoes congestion pricing decrease traffic?Short answer yes, generally.The Stockholm congestion tax was introduced in 2007, after being discussed for close to two decades. What really made it possible was a seven-month trial period (January to July 2006), which included some public transit expansion in addition to the introduction of tolls. Prior to the trial, public support for the system was low, at just 36 %. But a significant drop in traffic volumes measured during the trial changed that. 53 % of voters ultimately supported the decision to retain the system permanently. Since then, congestion has stayed low, with fewer delays on the roads than projected. In addition, its had an impact on the type of vehicles people drive over a three-year period, the share of cleaner, alternative-fuel vehicles on the roads rose from 3 % to 14 %.Singapore has continued to keep its traffic flowing relatively freely, even as the number of cars in the city-state has grown. Speaking to the NYT, economics professor Walter Theseira explained that pricing was just one lever used to keep the car fleet manageable. The other is a vehicle quota system which limits car purchases to only those Singaporeans who have a specific certification.The situation in the British capital is more nuanced. According to Transport For London (TfL), the number of vehicles driving into the city center dropped by 18 % during weekdays as a result of congestion pricing. But earlier this year, transport analytics company Inrix declared London as the most congested city in Europe, saying that the number of hours drivers spend sitting in traffic continues to increase. When asked why this might be the case, Alina Tuerk, head of transport strategy and planning at TfL told CBS News that its partly because some car lanes have been repurposed for other uses, such as walkways, bus lanes and bike lanes. This has reduced capacity for drivers, but it has increased capacity for other transport users, making Central London and the city a much more pleasant, people-centric place to be. But also increasing the throughput of people that you're getting through," Tuerk told CBS.NYC's congestion pricing zone has led to leading to faster bus journeys for commuters. Photographer: ... [+] Michael Nagle/Bloomberg 2023 Bloomberg Finance LPDoes congestion pricing increase uptake of mass transit?Probably. However, its likely that much depends the existence of extensive public transit networks, as well as the quality and frequency of services offered on them, and the demographics of those travelling.In Stockholm, the number of passengers on public transit was 4.5 % higher after the introduction of the congestion tax than before, but that just 0.1 % of the reduction in vehicle traffic can be ascribed to expanded bus traffic.A 2023 study looked at the impact of a sudden, temporary pause in the Milan congestion pricing scheme. It showed that bike-sharing declined by between 5% and 8 % during that time, which the authors attribute to the increase of road traffic congestion, which makes cycling less safe and pleasant.A survey of Beijing drivers in 2019 concluded that congestion pricing strategies were more effective than reward strategies in promoting mode shifts among more habitual automobile travelers.People living in London are relatively well-served by public transport, which explains why, in 2022, 67 % of Londoners travelled by active or public transit. But I didnt manage to find any research that explicitly links the adoption of the citys CCZs and LEZs to the use of mass transit.A recent study that looked at the London low emission zones and congestion charging zones showed ... [+] that together they have a statistically significant effect on long-term public health.(Photo by Hollie Adams/Getty Images)Getty ImagesWhat impact do congestion zones have on air quality?Overall, the effect on air quality is overwhelmingly positive.A few days ago, Londons City Hall (the office of the citys Mayor, Sadiq Khan) released a new report that showed significant improvements in air quality as a result of the ULEZ. Particle emissions (PM2.5) from vehicle exhausts are estimated to be 31 % lower on the outskirts of the city than they would have been without the ULEZ expansion. Nitrogen Dioxide (NO2) a gas known to impair lung function has decreased by 27% across the entire city, with central London seeing the largest drop. The data also showed that vehicles in the city are getting cleaner 100,000 fewer non-compliant vehicles were detected in London on an average day in 2024 than on an average day in 2023.Before introduction of its congestion charging zones, Milan had repeatedly violated European Commission targets for particular particulate matter (PM10 and PM2.5). Various studies have shown overall reductions in particulate emissions, as well as pollutants like carbon monoxide, since adopting a pricing scheme.In Stockholm, total emissions of NOx and PM10 fell by 8.5 % and 13 %, respectively, as a result of their congestion tax.Traffic congestion especially when it includes vehicles powered by fossil fuels is bad for us. A ... [+] 2014 study from The World Bank concluded that air pollution and injuries from on-road motor vehicles cause 1.5 million deaths globally each year.gettyDo we see any health benefits to reducing traffic?Yes, absolutely.Its been well established that traffic congestion especially when it includes vehicles powered by fossil fuels is bad for us. In fact, in 2014, a study from The World Bank concluded that air pollution and injuries from on-road motor vehicles cause 1.5 million deaths globally each year. That represents 2.9 % of deaths from all causes.There have also been several studies that aim to investigate the health impacts of congestion pricing schemes. The most comprehensive review of these studies was published in Lancet Public Health in 2023. It screened more than 2000 papers to find those that included reliable data on the health effects of low-emission zones (LEZs) and congestion charging zones (CCZs). From that, they focused on 16 studies from Italy, UK, Germany, Sweeden and Japan.Results varied across each health specific outcome they were interested in, but they concluded that LEZs have an overall positive effect on cardiovascular disease. In other words, lower emissions lead to better heart and circulatory health among populations living in those areas. In some instances, they also found that LEZs led to a reduction in the number of people suffering from respiratory conditions, and in Germany, the health benefits of LEZs were most felt by those over 65. CCZs were associated with reductions in road-traffic incidents, with lower overall incidence of injuries. Analysis of childhood asthma in Stockholm found that the introduction of a CCZ led to a drop in acute asthma visits to hospitals.And a separate paper from 2025 that looked at the London LEZs and CCZs showed that together they have a statistically significant effect on long-term public health.Overall, Id argue that congestion pricing is a positive thing to introduce to a dense city well-served by public transit services. So, Ill be watching what happens in New York with interest.