Online opinion

摘要

The subject of air pollution from diesel vehicles (see our April cover story), and how trade unions are becoming more aware of health risks to members who work outdoors, prompted reader J Hill to recall advice promulgated by the Transport Research Laboratory 15 years ago, which apparently stated that: "HGVs should be encouraged to maintain high gear in conurbations". Bollards, speed humps and other traffic calming measures installed by local councils in recent years, however, mean that heavy vehicles have to engage low gear, thereby emitting more particles, as J Hill pointed out.