On 1 June, stricter low emission zone regulations come into force in the Scottish city of Glasgow. But the new measure is already raising doubts. For reports show that the stricter environmental zone could lead to increased traffic in other parts of the city - and consequently not reduce climate-damaging emissions, but only displace them.
Last year, the Scottish city of Glasgow wanted to counteract the increasing pollution in the city centre and tightened regulations for the already active low emission zones. Now, a year later, the new rules are coming into force. But whether they will regulate traffic in Glasgow city centre for longer is currently unclear. As the tightened low emission zone could have a detrimental effect on neighbouring streets - for example, with each time motorists try to bypass the zone.
Several reports have warned the municipality that the planned measure to remove high-emission and older cars from circulation could lead to an "increase in car traffic on the periphery of the low emission zone". "For a number of roads" - a report states - "an overall increase in nitrogen oxide (NOX) emissions is predicted due to the introduction of the Low Emission Zone". An average increase in NOX levels of 14 per cent - and a maximum of 40 per cent - is to be expected. Streets east of the High Street, in Glasgow's West End and around Glasgow Green - as well as in Townhead - are affected.
Citizens and politicians are therefore unsettled about the traffic measure. Such an increase in traffic and the associated increase in polluting car emissions is far from what the city actually wanted to achieve with the new regulations for the low emission zones. Serious concerns about air quality in the city centre had led Glasgow to extend the city centre ban on all vehicles. Now the Scottish authorities' plans could have undesirable side-effects after all, causing more congestion and emissions in the rest of the city.
Even the Scottish Environment Protection Agency (SEPA) cannot ignore the negative effects that can be expected from shifting traffic to the outskirts. According to its own study, SEPA believes that the stricter driving bans "will mean an increase in traffic of up to 1,200 vehicles per day for a small number of roads" - which corresponds to a local increase in nitrogen oxide emissions of up to 34 per cent. The same is true for Edinburgh. According to the SEPA report, nitrogen dioxide (NO2) concentrations will increase significantly after the introduction of the zones - at least on the outskirts of the zones planned for 2024, such as Chester Street, Drumsheugh Gardens and Palmerston Place.
At the same time, critical voices from the conservative wing of the Scottish Parliament are becoming even louder. Not only because the city's own reports "suggest that its low emission zone could actually increase air pollution in surrounding areas" - explains transport spokesman and MP Graham Simpson. But also because "air quality in Scotland's major cities is already within legal limits". Introducing new zones, Simpson continues, would be "pointless and counterproductive" - especially given "the costs and difficulties these zones impose on residents and businesses".
The two cities, however, stand by their opinion. While "a small increase in traffic and emissions is expected in Glasgow's City West", modelling of the Low Emission Zone shows a much greater decrease in concentrations of the harmful air pollutant NO2 on all surrounding roads. The potential negative impact on local air quality will be short-lived and "the benefits of the scheme will far outweigh any negative impacts" - says Scott Arthur, Edinburgh Transport and Environment Commissioner. New monitoring systems will monitor the pollution situation in relation to the driving bans.
So where do cities go from here? Will the new and stricter regulations remain in place in Glasgow? Will additional traffic measures be put in place to protect air quality outside the city centre? Or will the opposition argue for the regulations to be scrapped? Will this also bring plans for an ultra-low emission zone in Edinburgh to a halt? The next few months will be crucial for the future of Scotland's low emission zones.
Nor should we forget all the Low Emission Zones already active in Scotland - as well as in the rest of Europe. As always, all the information is available on our website and in the Green Zones app.