Noise event measures for road traffic

How should noise events in road traffic noise be measured? This paper reports the performance of a set of algorithms that detect noise events in time histories of road traffic noise in the population of acoustic conditions found near roadways. The latter was obtained through simulation of 500 different road traffic noise time histories using a comprehensive range of traffic flow, traffic composition, and propagation distance, conditions in unshielded locations near roadways. The initial set of algorithms tested was developed by systematically expanding on threshold-based algorithms described in the literature, then excluding those that were unreliable. The finding was that the NA50 and NA55 (detecting when road traffic noise exceeded 50 dB and 55 dB respectively), and the NAL50E10 (detecting when the traffic levels exceeded L50 + 10 dB) can all be considered for practical application as event detection indicators. All apply to measurement of indoor events with the windows of the dwelling open. The primary criterion for selection as supplementary indicators (and others in the same clusters that could substitute for them) was their non-monotonic relationship with the LAeq, The traffic and distance conditions under which these event-based measures could potentially be useful supplementary indicators is identified.Griffith Sciences, Griffith School of EnvironmentFull Tex

Measurement of noise events in road traffic streams: initial results from a simulation study

A key question for road traffic noise management is whether prediction of human response to noise, including sleep quality, could be improved over the use of conventional energy equivalent, or percentile, measures, by accounting for noise events in road traffic streams. This paper reports initial results from a noise-events investigation into event-based indicators over an exhaustive set of traffic flow, traffic composition, and propagation distance, conditions in unshielded locations in proximity to roadways. We simulate the time-varying noise level histories at various distances from roadways using a dynamic micro-traffic model and a distribution of sound power levels of individual vehicles. We then develop a comprehensive set of noise event indicators, extrapolated from those suggested in the literature, and use them to count noise events in these simulated time histories. We report the noise-event algorithms that produce realistic, and reliable, counts of noise events for one-hour measurement periods, then reduce redundancy in the indicator set by suggesting a small number of representative event indicators. Later work will report the traffic composition and distance conditions under which noise event measures provide information uncorrelated with conventional road traffic noise indicators — and which thus may prove useful as supplementary indicators to energy-equivalent measures for road traffic noise

A study of the performance of a generalized exceedance algorithm for detecting noise events caused by road traffic

A key question for road traffic noise management is whether prediction of human response to road traffic noise could be improved by accounting for noise events instead of, or in addition to, energy equivalent or percentile measures of noise exposure. However, there is a critical prior question: how should noise events in road traffic be measured? Even at moderate traffic flow rates, detecting and counting noise events caused by road traffic is not a trivial exercise, and as yet there is no generally accepted noise event detection algorithm. This paper investigates the performance of a generalized exceedance algorithm for detecting noise events, constructed on the basis of the literature on noise events caused by road traffic. For this purpose, a microscopic traffic simulation model, coupled to an emission model that accounts for distributions of sound power levels of individual vehicles, is used to simulate one-hour time histories of the noise level in the proximity of a roadway, for an exhaustive set of traffic flow/composition and propagation distance conditions in unshielded locations. The validity and reliability of the number of noise events detected by the generalized algorithm in these one-hour time histories is then evaluated for a range of algorithm parameter sets. By discarding parameter sets that do not result in an algorithm that returns valid or reliable counts, and by examining redundancy in the remaining ones, a small number of representative parameter sets is identified, which may prove useful in the construction of event-based indicators supplementary to energy-equivalent measures of road traffic noise

Comparing noise policies of eight European cities using a noise intervention classification scheme

Over the last decades, cities have been developing noise policies. Comparing such efforts, however, is not straightforward. For this purpose, a previously proposed noise intervention classification scheme is used as a framework. This framework discriminates between source interventions, path interventions, closing/opening new infrastructure, other physical interventions (e.g. achieving a quiet side) and communication/education measures. Responsible officers dealing with noise at environmental departments of eight large European cities were interviewed. The invitations for an interview were sent out taking into account the geographical distribution of cities over Europe while a reasonably high position on a sustainable cities ranking was required. The interviews focused on the noise problem definition and what is in the noise management toolbox of the city. In addition, it is assessed how noise policies are evaluated, and to what extent public participation in the noise policy and planning process occurs. The interviews show highly contrasting opinions and practices among the interviewed cities at almost any aspect of the noise management process

Prospectus, November 9, 1976

ADAMS AND PARKS: RUNNERS HEAD FOR NEW YORK; Business as usual: Stu-Go discusses \u27disaster bus\u27, pins; Computer data banks on you; Final exam schedules posted; PC news in brief: Big Walter here today, Library open Dec. 18, See Chicago Bulls Nov. 30, Buy a ticket, turkey!, Christmas shopping trip, College Forum; Traditional Vet\u27s Day; What does it mean?: Chapter 11, Nobel winner; Letters; Big Walter Horton plays today; Alexander Prospectus ad manager; Teachers, too: H.S. Students visit this week; Museum trip scheduled for Nov. 20; Senior citizen play preview planned for Nov. 17th; Exploring new worlds living in Outer Space; Asses make basketball players of themselves; Capsule to be buried; Campus Life band hit with audience; Don\u27t worry about it: Midterms are only an indication, not a grade; Classifieds; Football poll deals with playoffs, other concerns; Bears exceed, STP needs boost; Spikers could net national berth this weekend; Fisher ignores tip, wins Fast Freddy; Fast Freddy\u27s Football Forecast; Cobra\u27s Corner: Adams getting antsy for New York meet; PC students can swim free on Tuesdays; I.M. finals approaching; Games of November 13-14https://spark.parkland.edu/prospectus_1976/1004/thumbnail.jp