Documents about Zones:
Environmental Zones regulations, an overview by Swedish Municipalities
List of approved aftertreatment devices (particulate filters)
Emission Regulations
The biggest cities in Sweden—Stockholm, Gothenburg, Malmoe, and Lund—introduced Environmental Zones in the center of each city in order to improve the ambient air quality and also, to a certain degree, reduce noise from heavy duty vehicles. The “Environmental Zones” regulations are not harmonized with the European Union emission standards. They are made possible by a decree dealing with vehicles and the use of vehicles. The decree makes it possible for communities in Sweden to introduce limitations for heavy duty vehicles in “environmental sensible areas”.
The first Environmental Zones regulation—which became effective on July 1, 1996 in Stockholm, Gothenburg, and Malmoe—introduced emission control requirements for diesel particulate matter (PM) and hydrocarbons (HC). The regulation was then modified, effective January 1, 2002, by adding a nitrogen oxides (NOx) control option. The Environmental Zones program applies to trucks and buses powered by a diesel engine and with a gross vehicle weight of more than 3.5 metric tons. The basic requirement for entering the Environmental Zones is that all heavy-duty diesel vehicles must not be more than 8 years old, as determined from the first date of vehicle registration. Older vehicles, depending on their age, can be either exempted from the regulations or banned in the Environmental Zones. Vehicles of a certain age have to be retrofitted with an approved emission control device in order to receive an exemption and to be allowed to travel in Environmental Zones.
A general exemption from the regulation is granted for vehicles aged 8 years. All vehicles older than 15 years are banned. Vehicles aged from 9 to 15 years must be retrofitted with an emission control device. The required emission reductions for retrofit equipment are listed in Table 1.
| Pollutant | Emission Reduction* | |
|---|---|---|
| Level B | Level C | |
| Diesel Particulate Matter (DPM) | 80% | - |
| Hydrocarbons (HC) | 80%a | - |
| Nitrogen Oxides (NOx) | No increase | 35% |
| Noise | No increase | |
| * “Type A” systems of 20% DPM reduction were also allowed at the initial stage of the program. Starting in 1999, vehicles equipped with Type A systems are not permitted in the Zones. a - 60% HC reduction was required before January 1, 2002. |
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Different aftertreatment devices and their combinations provide different extensions of the traveling period in the Zones. The exact number of additional years retrofitted vehicles are permitted to enter the Zones also depends on the vehicle model year, as specified in the regulation. As an example, a model year 1993 vehicle will be allowed to enter the Zones until 2005 if retrofitted with a Level B system, or until 2007 if retrofitted with a Level B+C system. Special exemptions can be granted for engines meeting Euro IV or better emission standards. Special rules also apply for vehicles designed for special purpose and vehicles seldom traveling in the Zones.
The approved emission control devices are catalytic converters in combination with particulate traps. The systems are effective due to the widespread use of low sulfur diesel fuel in Sweden. Low sulfur diesel fuel of max. 10 ppm S accounts for more than 90% of the total use in all HDVs. NOx control systems, such as retrofit EGR kits, are expected to receive approval for use in the program.
Certification and Enforcement
At the beginning of the program, MTC AB (at that time a subsidiary of the Swedish Motor Vehicle Inspection Company, ASB) was responsible for approving the retrofit kits and also for the approval of each vehicle. Later, the cities have modified the regulation to allow any testing laboratory with an accreditation to perform the testing and certification services.
The manufacturer of retrofit equipment submits documents to an accredited laboratory and applies for an approval of the equipment according to the requirements given by the cities. The application forms supplied by the laboratory together with test results and the requirements for installation of the equipment on the vehicle are included with the application. The documents are reviewed and an emission test of the equipment is carried out at the laboratory. The test is carried out using a representative combination of vehicle and aftertreatment device on a chassis dynamometer. The driving cycle is the Braunschweig City Driving Cycle, representing a typical driving pattern for a bus or a distribution truck traveling in a city area.
When a device is installed on a vehicle, it must be subjected to an individual approval. This task is carried out by one of the I&M stations run by ASB. After acceptance of the installation, a sticker is placed on the windshield. The enforcement of the regulation is the responsibility of the police.
Emission Benefit
An evaluation of the program effectiveness, carried out 1 year after its introduction, showed the following emission reductions from heavy-duty vehicles:
- DPM - 20%
- HC - 10%
- NOx - 8% (mainly due to renewal of the vehicle fleet)
- reduction in total noise level, despite increasing traffic.
Another consequence of the program is an increasing population of CNG and alcohol fueled heavy-duty vehicles in the Zones.
Estimated 3000 vehicles have been retrofitted with emission control systems over the first 3 years of the program duration.
It is expected that more cities and communities in Sweden will follow the footsteps of Stockholm, Gothenburg and Malmoe and establish Environmental Zones.
This article based on information submitted by Lennart Erlandsson, MTC.