Small particulate matter (PM10, PM2.5) is a nasty pollutant that is prevalent in a lot of cities.

Some of these emissions come from exhausts (tailpipes); regulation has spurred on technological developments, and modern clean fossil-fuel engines have much lower particulate emissions.

However, particulate levels are still high, and a large part of the problem is that transport causes a lot of these, from abrasion of tyres, road surface, brakes and clutch.

I can imagine lots of possible routes to curbing these, from changes to materials used in making the sources of the particulates to suppress their creation, to cleaning / scrubbing regimes to prevent their atmospheric suspension. And presumably curbing vehicle flows is a very effective mechanism.

Beyond curbing vehicle flows, What is best practice in reducing the pollution of non-exhaust transport-sourced particulates?


2 Answers 2


These reduce the pollution not by preventing particle emission, but by cleaning up afterwards:

  1. Plant trees and shrubs.

Urban tree leaves remove fine-particulate air pollution

This will reduce particulates (in the air) from any source, of course, so including exhaust sources.

  1. Sweep the streets.

Resuspension of road dust contibrutes to the atmospheric pollution, so cleaning the road surface helps. This gives moderate results in urban areas


Creating a Personal Rapid Transit (PRT) system that uses rails would heavily reduce the amount of particulates from tyres, and probably from braking too (more heavily used vehicles can justify higher tech components). They also are well suited to electric propulsion. PRT systems haven't been built on a large scale yet, but I do remember reading that when subjected to computer traffic modelling they scaled better than other modes of transport.

There is one that runs on rails in Suncheon, South Korea, named SkyCube. It opened in 2014 by the look of it.

  • Does rail traffic generate particulates too, from rail abrasion and from brakes?
    – 410 gone
    Commented Jan 28, 2015 at 9:58
  • @EnergyNumbers, possibly; with braking, it depends on the brakes. Regenerative braking probably wouldn't though, and that would be a very suitable braking design for heavily utilised vehicles powered by electrified rails. In the long term, I suspect PRT systems may replace our existing roads. Particulates from rail abrasion would be fairly minimal I expect. Commented Jan 28, 2015 at 21:50
  • @EnergyNumbers steel wheels on steel rails eliminates the rubber and road surface particulates, even if everything else is unchanged (which is unlikely, since most PRT systems are electric so also eliminate local particulates from combustion)
    – Móż
    Commented Aug 27, 2015 at 4:28

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