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Navigating Low-Emission Zones

Why cities aim to change how we travel by Holden Foreman

Imagine attending a work meeting in an unfamiliar city, tens of miles away from home, for the first time. You must adjust your morning schedule, waking up earlier than usual in order to reach the meeting. After rushing to get prepared, you get into your car, a used 2008 Volkswagen Jetta that you recently purchased for your daily commutes. After all, you wouldn’t make it to work on time by riding a bicycle, and your access to public transit between cities is limited. As you drive, you find yourself on track to arrive 10 minutes before the meeting. But when you reach the city limits, you are shocked to see on a road sign that vehicles failing to meet Euro 4 emission standards are forbidden entry. The ban applies to your vehicle, and you will now be late to your meeting.

Although this is a hypothetical scenario, its likelihood is increasing. Oxford and other cities around the world are currently taking steps to implement low-emission zones (LEZs), areas in which vehicles must meet certain emission standards lest they face a fine or ban. In Oxford, the City Council has proposed a specific type of LEZ known as a zero-emission zone (ZEZ), to be implemented by 2035. A ZEZ forbids all vehicles with tailpipe emissions, leaving one to wonder what types of vehicles can be driven in such a zone. Electric vehicles (EVs), including battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs), do not release tailpipe emissions and therefore qualify for use in zero-emission zones. But for cities looking to clear congestion and develop picturesque streets, it is often preferable that the only vehicles on the road are those deemed necessary in specific circumstances, such as health emergencies, or for individuals with exceptionally inhibited mobility. 

Although they are ostensibly beneficial for the environment, it is worth exploring why else ZEZs are desirable. In 2017, the European Union issued a ‘final warning’ to the United Kingdom for persistent violations of air pollution limits across the country. After failing to adequately address matters brought up in other similar warnings, the UK was referred to the European Court of Justice in May this year, along with France, Germany, Hungary, Italy, and Romania. These referrals occurred after a 2017 report from the European Environment Agency, which attributed over 500,000 premature deaths to air pollution across the 28 EU countries at the time (including the UK). It has become abundantly clear that an alternative to petrol and diesel vehicles in urban areas is necessary. 

EVs may provide the answer. For people running errands and undertaking long-distance travel, EVs offer both practicality and preservation of air quality. Imagine if, after a long day at work, even from an office that is only 2 miles from your home, you are asked to pick up the weekly shop on the way home. Balancing such cargo on a bicycle would likely prove difficult and even dangerous, whereas transporting it in the boot of an EV would be simple. These difficulties are often compounded for families with young children, for whom mobility by car is almost essential. EVs offer far greater utility than bicycles for the modern way of life, while releasing an equivalent amount of emissions: zero.

As of now, however, very few people worldwide own EVs. In fact, the Centre of Automotive Management (CAM) found only 2 percent of all vehicles newly registered in the first 3 months of 2018 were EVs. Norway had the highest share of EVs registered, at 48 percent, but the country is an outlier by several factors. It has offered some of the most ambitious EV-incentives on the planet, including tax exemptions, priority parking and bus lane access. These incentives cost the government (and taxpayers) money, of course, but parties in Norway and beyond argue that such investments are worth it to help mitigate the damages and costs of poor air quality. However, Norway’s generous set of incentives represents an outlier in terms of EV-friendly policy. So how are other countries implementing cost-effective reform?

Although ZEZ initiatives have proliferated rapidly in the 2010s, less strict LEZ policies experienced their own growth surge in the 2000s. London has operated a Congestion Charge zone, in which drivers of personal vehicles must pay a daily fee to drive, since 2003. Elsewhere, in 2008, the German cities of Berlin, Cologne, and Hannover independently implemented the country’s first three LEZs, known as environmental zones. The government provided a framework for such zones, of which more than 20 have been formed, but they are individual city initiatives. 

In both Germany and London, studies have found LEZs to correlate with reduced emissions in the affected areas, but the broader effects of LEZs remain unclear due to confounding factors. Weather phenomena, infrastructure developments and non-LEZ policies, for instance, can change during studies of LEZ impacts and may skew the collected data. Furthermore, as people shift driving habits in response to an LEZ, pollution may be displaced beyond the area being studied, increasing danger in other communities.

LEZs often come with exemptions meant to address numerous special circumstances. For instance, vehicles carrying people with disabilities or people experiencing life-threatening medical emergencies are generally exempted from conforming to LEZs, and public transit still operates within most LEZs, regardless of whether the buses or other transit vehicles have been electrified. This is further evidence that LEZs are primarily a tool to promote ‘mode shift’: convincing those who drive passenger vehicles to use alternative methods such as walking, biking and riding public transit.

Recent policy developments have emphasized the role of ZEZs in combating air pollution. The exemption of EVs from the London Congestion Charge Zone, starting in 2003, laid the foundation for London’s present implementation of a ZEZ, which is developing in multiple phases with increasingly strict emissions standards. London is not alone in implementing a ZEZ as a policy tool for clean air. In 2017, the mayors of 12 cities across 4 continents, joined later by Rome and Heidelburg, signed the C40 Fossil-Free-Streets Declaration, including a pledge to make ‘a major area’ of each city a ZEZ by 2030. Two of the original signatory cities, Mexico City and Paris, also committed in December of 2016 to ban diesel vehicles by 2025. And as of 2020, Oxford will begin its own transition to a zero emission city.

For its own ban on vehicle emissions, Oxford plans to follow a phased approach, such as that seen in London, by first restricting vehicles below specific emissions standards on specific streets, before eventually restricting all vehicles in the city center. Once all non-ZEZ vehicles have been banned emissions in one, smaller central area, the ban will be expanded outward twice by 2035. A study performed by the city found that, by 2035, the proposed Oxford ZEZ would lower NO2 levels in George Street, the most polluted street in the city center, by 74 percent. 

A hastily organised LEZ could jeopardise future efforts if it prompts backlash.

While the environmental benefits of LEZs have been demonstrated, a hastily organised LEZ could jeopardize future efforts if it prompts backlash, especially with regard to the welfare of local businesses and underprivileged community members, who could be substantially threatened. In Greater Manchester, UK, a government-backed CCZ was rejected by all 10 local councils in a 2008 public referendum. The zone was put to vote during the economic downtown, an especially fragile time for environmental policy, and proposed as the UK’s largest CCZ of the time, it was seen as untenable to local people. Similarly, more than 74 percent of Edinburgh residents voted against a CCZ for the city, amid concerns over lacking transportation infrastructure and potential traffic displacement as a result of the proposed zone. These incidents illustrate a broader issue: individual cities – and their residents – are not always willing to commit to global or even national air quality efforts if such efforts seem to sacrifice local economic prosperity.

In an effort to address this concern, Oxford City Council sought public input regarding its proposed ZEZ in 2017. The public consultation participants included 755 individuals and businesses. Although most of those consulted described themselves as either ‘supporting’ or ‘strongly supporting’ the proposed ZEZ, participants were strongly divided regarding the extent of the three proposed ZEZ areas. Less than a third approved of the suggested zones, with contingents supporting both smaller and larger zones, leading to anything but a consensus. Considering this diversity of opinions, even among supporters of the scheme, it is clear that ZEZ proposals remain controversial.

While people with regular commutes may be concerned over public transit infrastructure or the cost of penalties for violating a given LEZ, the revenues are generally invested into public transit infrastructure such that disadvantaged community members have improved access to transit in place of what otherwise may involve purchase of a relatively expensive EV. 

Cities have planned other methods for easing people without EV access into the reality of LEZs. One idea is subsidizing vehicle retrofitting costs for people with vehicles below required standards. While subsidies would ostensibly benefit the people receiving the funds, issues arise when deciding who pays for the subsidies. Raising taxes is unpopular and may threaten the economic viability of the scheme. However, subsidies have proved to be effective when implemented, as exemplified by Norway’s world-leading EV adoption.

The primary goal of LEZs, in Oxford or any other city, is mode shift. While it may seem unjust for a city to prevent you from reaching your place of work due to the age of your automobile, the ultimate goal for cities is to make public transit and walking the more convenient means of transportation. In shifting people away from polluting vehicles, LEZs are not just a factor in the fight against air pollution, but also a factor in the global fight for an increased quality of life, without the noise, traffic, and wasted energy of today’s most common automobiles. Studies show the impacts of LEZs have been promising, but the political popularity of such zones remains to be seen.

Holden Foreman is an undergraduate at Stanford University studying electrical engineering. He interned at the California Environmental Protection Agency in 2018.


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