Noise is a critical environmental consideration in the transport industry. The noise from transport systems (roads, aircraft and railways) is increasing every day; therefore, it’s a major factor responsible for noise pollution. Also, more and more people are getting exposed to transport noise, and the corresponding detrimental health effects (i.e., sleep disturbance and annoyance) are becoming more severe. Due to the current state of the transport industry with regards to noise pollution, various jurisdictions have issued regulations and guidelines on how to reduce the harmful effects of transportation noise.
A growing body of research reveals that transport noise can also cause cardiovascular disease, psychological problems, elevated hormone levels, and even premature death; studies on children have identified worsened behavior, cognitive impairment and diminished quality of life.
At first glance, the obvious remedy would seem to be reducing transport volumes. This would not only address the problem of noise pollution but also reduce air pollution and cut greenhouse emissions. Contrarily, responses such as building new roads further from residential properties, may offer few ancillary benefits or even worsen other environmental problems.
Measuring noise levels in the transport industry is particularly important to highway planners and designers. Transport agencies will utilize sound measuring equipment to measure different aspects of highway noise, for example, to predict or determine the impact of urban planning in the community.
Cutting traffic will undoubtedly go a long way in helping to mitigate transport’s environmental impacts. As a noise mitigation strategy, however, it has several limitations. Reducing car traffic with a high proportion of trucks, lorries and buses, for example, has a minimal impact on the overall noise levels as the heaviest vehicles mask the noise produced by small cars. A practical alternative strategy, therefore, would be to target the heaviest vehicles first. But on roads where vehicles produce almost similar amounts of noise, traffic would have to be reduced by about 40% before starting to perceive reduced noise levels.
Urban planners and policymakers have to identify cost-effective, complementary measures that reduce noise at the source including:
- Improvements to infrastructure, such as low noise rail tracks and roads.
- Technological improvements to aircraft, trains and vehicle components including, low noise train wheels, tires, landing gear and brake-blocks.
- Restricting access to the noisiest aircraft and vehicles (e.g., at night)
- Improved soundproofing and noise barriers of surrounding buildings and residential premises (although only as a last resort because such measures are rarely-cost effective).
- Traffic management techniques, such as controlling the speed of vehicles, traffic calming and low noise operational procedures for aircraft.
- Urban planning to discourage settlements close to airports, busy roads or railways, and rules on the layout, acoustic quality and location of buildings.
Measuring Transportation Noise
Usually, the objective of monitoring the sound levels will dictate the location of microphones, for example. In general, you want to choose measurement sites that are clear of vertical sound-reflecting surfaces and obstructions. Avoid extreme locations-either too close or too far from the road to avoid overstating or understating noise levels and impacts.
Use a microphone height of about 5ft above ground (average ear height of a standing person) for multistorey buildings or homes with outdoor decks, then microphones placed at 5 ft above the floor elevation may be required.
Bottom Line
Everyone has the right to enjoy a conducive living environment that doesn’t pose any health risks. Noise pollution from transportation can be controlled with the right policies and technology. Active noise mitigation is just one of the ways to improve society. As cities grow, transport systems expand, and it is only through proactive noise mitigation that you can ensure noise levels are controlled.