Know thy enemy in the exhaust

Posted on November 18, 2020

When it comes to the environment, we all agree it needs protecting. It is arguably only Aloysius O'Hare from Dr Suess' The Lorax that will sing about the trees: "I say, let it die, let it die, let it die..." 

Yet, when it comes to the emissions from our vehicles, we seem to be conveniently oblivious. A new car sold in the South African market must declare its fuel efficiency and CO2 emissions. You are unlikely to experience that excellent reported fuel efficiency, though. Why? They attribute the difference to driver behaviour, the weather, road grade (the in/decline of your route), and general driving conditions. You see, the reported fuel efficiency follows from chassis tests under strict and controlled conditions. The same argument holds for emissions.

Yet, we as South Africans experience the real effect of transport emissions daily in our cities. Our vehicle population is, on average, much older than the developed world who eagerly subscribe to and seek Sustainable Development Goals (SDGs). We should diligently pursue them too. Unfortunately, our ageing vehicles emit much more than their reported emissions because real people drive them. Again, why the difference? Because our cars and trucks expose us to actual driving behaviour on actual local road conditions and, yes, in beautiful South African weather.

The infamous international Volkswagen diesel scandal, amongst others, sparked a global movement to enhance vehicle certification to include Real Driving Emissions (RDE) testing. In line with this state of the art development, the Centre for Transport Development at the University of Pretoria, in the Faculty of Engineering, Built Environment and Information Technology (EBIT), acquired a Portable Emissions Measurement System (PEMS). The PEMS unit connects to the exhaust of a light or heavy vehicle. It allows one to measure a variety of pollutants while driving under real and regular conditions. The unit and the Centre's capability is the first of its kind in Africa. Prof Johan W. Joubert and his team at the Centre is building up a database of emissions and vehicle diagnostics on a variety of road types and vehicle loads in Gauteng. The current cohort of test vehicles includes the University fleet of light vehicles and the NRF Road Rail Vehicle (RRV), a heavy goods vehicle.

The research has two main goals. Firstly, to study and understand the uncertainty and the variance in vehicle emissions in the local environment. How do our South African vehicles perform really? If we do not know, and we don't, then we poke blindly in the dark to try and improve the state of transport emissions. Secondly, to inform policy when it comes to setting realistic targets. The reality of carbon tax, as one intervention, is on the cards. But if we get it wrong, it may have many unintended consequences that will hurt the economy and its citizens. Urging everyone to buy electric or hybrid vehicles sound utopian, but it may only be achievable for the financial elite; adversely affecting economic inequality. If freight vehicles are taxed disproportionately, it will manifest itself in the price increases for essential goods on the shelves, hurting us all. More so, the poor and economically vulnerable.

The University, its School of Engineering, and the Department of Science and Innovation through the RDI Waste Roadmap, are putting their money where their mouths are. Smart Cities require Smart Mobility, and the multidisciplinary Centre for Transport Development is providing evidence-based research to make smart a reality. 

- Author Prof Johan W. Joubert
Published by Dudu Mathe

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