There are currently many projects aimed at reducing the air pollution emitted in automobile exhaust, but in the meantime couldn't we just … redirect that exhaust? A new study suggests a possible means of doing so.
Although vehicle exhaust can be problematic throughout a city, it's particularly harmful to pedestrians walking alongside busy roads. It's especially hard on children since they're closer to the ground, towards which the airborne particulates gradually settle. Additionally, vortexes forming in the air above sidewalks can actually concentrate the exhaust near pedestrians.
In countries such as Germany and the Netherlands, some motorways are already flanked by inwards-curving walls that reflect traffic noise back onto the road and away from homes. Inspired by these – and by the engine-noise baffles used at airfields – Imperial College London's Dr. Tilly Collins envisioned similarly curved roadside barriers that could deflect exhaust back towards the vehicles.
Working with Dr. Huw Woodward, she proceeded to develop simple airflow models that replicated the effect of such structures. According to the university, testing with these models suggested that the barriers would "effectively disperse and reflect pollutants back towards the roads and would very rapidly improve air quality for pedestrians in an inexpensive manner."
As an added bonus, the structures would also reduce the volume of traffic noise reaching pedestrians, plus they could serve as scaffolds for roadside greenery – presumably of the hardy variety.
That said, the structures would likely also reduce visibility both for pedestrians checking for approaching vehicles, and for motorists checking for cross-traffic at intersections. Nonetheless, the scientists believe their findings are encouraging enough that the concept should be explored further.
The research is described in a paper that was recently published in the journal Cities & Health.
Source: Imperial College London
