Noise News for Week of October 25, 1998

Truck Noise is a Greater Concern

DATE: November 1998
BYLINE: Larry Kahaner
DATELINE: Washington, DC

Fleet Owner reports that one reason for the high number of complaints is the sheer number of trucks. Truck traffic has increased almost sixfold between 1960 and 1995, according to the Dept. of Transportation (DOT). The other reason is that grass-roots anti- noise groups are no longer considered kooks by politicians. Congressional researchers say nearly 20-million Americans are exposed to noise levels that can lead to cardiovascular problems, strokes, and nervous disorders. Another 40-million are exposed to noise levels that cause sleep or work disruption.

Fleet owner reports that noise is such a reliable stress inducer. Pharmaceutical companies use it to test their stress drugs on people, says Eric Zwerling, director of the Rutgers Noise Technical Assistance Center.

The article states that according to trucking industry officials, noise complaints are not something they hear about until drivers report that a usual route has been restricted and they've been forced to take a longer, often slower route. One day there's a sign that says No Trucks and they've got to find another way, says one LTL dispatcher who asked that his name not be used. The problem isn't us. It's the smaller fleets or the independents and their modifications of exhaust systems but we all pay the price.

According to the article, one of the most common signs being installed, even in larger cities, outlaws the use of engine brakes. Scott Fowler, vp-sales and marketing for Jacobs Vehicle Systems, says the company's Jake Brakes meet noise standards as long as there is no tampering with engine exhaust systems. A properly muffled truck is not objectionable, he says. Fowler says that his company favors enforcement of laws that prohibit tampering with exhaust systems because that keeps engine brake noise down and prevents his company's products from being painted with a negative broad brush.

The Federal Highway Administration (FHWA) has set noise levels for trucks traveling along an interstate road at 85 decibels (dB). However, states and cities may set lower standards for private property or certain streets. New Jersey, for example, sets a level of 65 dB for private facilities such as shopping malls or terminals during the day and 50 dB at night. How can you expect a truck to go from 85 dB one minute to 65 dB the next? asks Zwerling.

Fleet Owner feels that technology must also play a role in quieting turcks. It quotes Jim Higgins, spokesman for Mack Trucks, who claims their goal is to continually drop the noise level of its trucks with every model year. The trucks meet FHWA noise standards, but new moves such as pilot injections to reduce combustion noise at idle and low load and isolating valve covers from the head will yield a tremendous drop in noise, says Higgins.

The article notes that there has been slow but steady use of quiet pavements, which absorb noise from tires rolling along at high speeds. These are very common in Europe, these porous pavements not only cut ambient noise almost 30% and offer better drainage and skid resistance. The drawbacks are higher installation and maintenance costs.

DOT reports that the number of trucks driving through city streets and towns has increased twice as fast as the number of trucks using interstate highways over the past ten years. Citizens are becoming more vocal and their local legislators are responding in creative ways. One upstate New York community angry at truck noise from a nearby toll plaza and wanting it relocated passed an ordinance that outlawed trucks from idling longer than ten minutes.

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