ISO 11819-1:2023

Overview

ISO 11819-1:2023 - Acoustics: Measurement of the influence of road surfaces on traffic noise - Part 1: Statistical pass-by method (SPB) - defines a standardized way to compare traffic noise produced by different road surfaces. The method assigns sound levels representing light and heavy vehicles at selected speeds to a tested surface, under free‑flowing traffic conditions (posted speeds of 50 km/h and above). It is not applicable where traffic is congested or at junctions. The updated 2023 edition integrates previous guidance (including ISO/PAS 11819-4) and introduces practical refinements such as a backing board variant and optional additional microphone height.

Key Topics and Requirements

• Measuring principle: Statistical pass-by (SPB) recordings of individual vehicles under constant-speed conditions (Clause 5).
• Instrumentation: Requirements and verification for acoustical, speed and temperature instruments (Clause 6).
• Test site selection: Free-field considerations, reflections, guard rails and surface between road and microphone; backing board use where free-field is difficult (Clause 7, Annex C).
• Traffic and vehicle classification: Definitions and minimum sample sizes for light and heavy vehicle categories; updated vehicle nomenclature and weight thresholds (Clause 8, Annex A).
• Measurement procedure: Microphone positions, calibration, sound level and frequency spectrum capture, speed and temperature logging (Clause 9).
• Normalization and corrections: Regression and speed normalization, temperature corrections, combining vehicle categories, and spectrum normalization (Clause 12).
• Uncertainty and reporting: Measurement uncertainty, confidence intervals and detailed reporting requirements; example test report provided (Clauses 13–14, Annexes D, H, I).
• Annexes: SPB index determination, backing board method, reference road surface, monitoring stability and uncertainty guidance.

Applications

• Surface classification: Classify and compare acoustic performance of asphalt, porous, or dense surfaces.
• Quality control: Verify conformity of production for low-noise surfacings.
• Lifecycle monitoring: Track acoustic performance over service life relative to new condition.
• Comparative studies: Evaluate a tested surface against a reference surface or at different locations.
• Research & policy support: Provide data for road and environment authorities without prescribing noise limits.

Who uses this standard

• Acoustic consultants and laboratories
• Road and transport authorities
• Pavement engineers and material manufacturers
• Contractors, researchers and environmental assessors

Related standards

• Other parts of the ISO 11819 series and complementary acoustics standards from ISO/TC 43 and CEN. See ISO for the full list of related parts and guidance.

Keywords: ISO 11819-1:2023, statistical pass-by, SPB method, traffic noise measurement, road surface noise, tyre/road noise, backing board method.