U.S. Department of Transportation
Federal Highway Administration
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In the following sections, the team arranged the material by subject area and provided details on a country-by-country basis. The team believes this arrangement provides the reader of the report with maximum accessibility to the information. For example, a reader with a primary interest in maintenance can go directly to the topic of interest and determine what each country visited has experienced or is planning to implement. To increase the readability of the report, the team decided to provide summary information by topical area as the official report.
Chapter Two begins with common issues evident in each country. All countries visited are members of the European Union (EU).
In Europe, research indicates that 17 percent of the population is exposed to environmental noise levels of more than 65 dBA, a level that can have negative health effects. The research involved the repeated testing of 138 people at 12 sites, and discovered that small increases in noise level matched changes in behavioral disturbance. The research used two psychometric scales to assess change in community annoyance and responses to road traffic noise due to a surface reseal (urban areas). Behavioral disturbance reduction was detected even when the reduction in noise was very small (3 dBA). The participants identified the source of noise annoyance as being the road surface interface as opposed to cars, trucks, or other characteristics, such as service covers.
These research studies appear to be the basis for Directive 2002/49/EC of the European Parliament and of the Council of June 25, 2002. Although this directive, called the Environmental Noise Directive (END), appears to be based on a correlation between noise and health, the supporting research is not considered definite and additional research is required. This EU directive requires all members to do the following:
The critical date contained in the directive is June 30, 2007, when all member states must have completed the first round of strategic noise maps identifying areas of concern. A general principal of EU law prohibits countries from imposing stricter guidelines where an EU policy exists.
The EU directive required contour lines to be drawn for 55 to 75 dBA for daytime and 50 to 70 dBA for nighttime, in 5-dBA increments, to determine which areas are impacted by highway traffic noise. For cities with populations exceeding 100,000, major transportation actions must combine with an action plan to provide quiet zones. In addition, the directive addressed the L den (day-evening-night sound level) noise metric for calculating the contours. Based on noise annoyance, this metric applied a 5-dB penalty for evening hours (6 to 10 p.m.) and a 10-dB penalty to nighttime hours (10 p.m. to 6 a.m.). The EU is investigating the application of the L Amax (maximum A-weighted sound level) metric in helping to determine noise impacts.
As part of the EU, these countries will implement the use of the noise prediction methods known as HARMONOISE (Harmonised, Accurate, and Reliable Prediction Methods for the EU Directive on the Assessment and Management of Environmental Noise) and IMAGINE (Improved Methods for the Assessment of the Generic Impact of Noise in the Environment), the latter being a simpler version for the purpose of validation. HARMONOISE includes meteorological conditions, and the noise metric is an average 1-year L den. Calculations are performed on a one-third-octave band basis from 25 to 10,000 Hertz (Hz). The following are the three main elements of the model:
The model can account for noise sources other than highway (e.g., rail).
As early as the 1970s, many European countries had already begun their journey toward lowering roadway noise. Research, development, and implementation of noise barrier walls, building insulation, building codes, noise limitation on new roads, traffic handling, and pavement type selection were well underway in many countries based on consumer complaints of excess noise or differential noise.
For example, it is recognized that quiet pavement systems reduce the tire/pavement noise profile. However, questions remain about the duration of the noise reduction and the benefit each different system can provide. Based on the outcome of the mapping, it is anticipated that each country will begin a prioritization process to eliminate noise “hot spots.” Other EU directives provide a means of reducing vehicle and tire noise. Thus, European countries are leaning toward harmonization of technical specifications for vehicles and are performing test procedures (ISO standardization) to standardize the process of tire/pavement measurement. However, the Environmental Tire Noise Directive in particular appears to permit considerable flexibility, and most countries have indicated that they do not anticipate significant noise reduction through further vehicle improvements.
Officials noted that on a national and European level, vehicle noise emission limits were reduced between 1970 and 1996 from initial values of 92 dBA for trucks and 82 dBA for passenger cars to 80 dBA for trucks and 74 dBA for cars. These are nominal values; since measurement methods have changed somewhat over this time period, the actual limit reductions are higher for trucks and lower for cars than the given nominal reductions. When Austria began requiring vehicles not to exceed 80 dBA at night on major highways over the Alps, vehicle manufacturers rapidly adapted to the situation and provided trucks that met the new limit, which was then 4 dBA lower than the general European limit for such trucks. Optimally, passenger vehicles would have a limitation of 74 to 80 dBA, depending on vehicle type and engine size. Although many believe that tires can be changed easily to produce lower noise levels, reductions in tire noise by tire manufacturers to date have been offset by the demand for wider tires, which produce more noise. One option under consideration to encourage the production of low-noise tires is to offer financial incentives. Several countries indicated that in some cases, the EU Environmental Tire Noise Directive's flexibility might be a constraint in promoting the production of low-noise vehicles and tires. However, an additional directive is in place on low-noise tires that affects new tire types introduced in 2004, original equipment manufacturer (OEM) new vehicles in 2005, and all new aftermarket tires from 2006 through 2011. The noise regulation is based on tire width—an increase of 10 mm results in a 0.4-dB noise increase.
“You can't limit production of louder vehicles, but you can limit where they can drive.”—Eric Vos, Ministry of Transport, Public Works, and Water Management
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