Improving the CPX method by specifying reference tyres and including corrections for rubber hardness and temperature

Erik Bühlmann
Marco Conter
Piotr Mioduszewski
Reinhard Wehr

Recently completed work in the EU project ROSANNE and in working group ISO/TC43/SC1/WG33 has allowed substantial improvements to measurements made by the Close-Proximity (CPX) method, intended for measurement of noise properties of road surfaces. The paper summarizes the experimental work and describes the conclusions and implementation in ISO/FDIS 11819-2 (the CPX method) and in the supporting ISO (draft) Technical Specifications 11819-3 about Reference Tyres and 13471-1 about Temperature Corrections.

In the Reference Tyre specification, two reference tyres are defined, of which one is the 16'' SRTT specified in ASTM 2493-14 and the other is a commercial light truck tyre. Both tyres have been tested with respect to correlations with SPB (pass-by) measurements and found to represent car and truck tyres, respectively, in this particular application. To account for reasonable ageing and minor production differences, a correction for rubber hardness is specified, in order to normalize measurement results to tyres having reference hardness. The Temperature Correction specification includes temperature coefficients that are used for normalizing noise levels to an air reference temperature of 20 degrees C. The coefficients relate to driving speed by a simple equation which is different for three categories of road surfaces, which are specified in the document.

MEET US


7
Dec

Shipping and the environment – research meets reality

Centre for Transport Studies (CTS) in co-operation with Ports of Stockholm invite you to the seminar Shipping and the environment – research meets reality.

LATEST NEWS


2017-10-26

Simulation of cut-in by manually driven vehicles in platooning scenarios

A study in a VTI-driving simulator has showed that a platoon will be able to handle a cut in from a manually driven car. The results of this study have recently been presented at two conferences in Japan.


2017-10-16

ERPUG Forum

The five-year anniversary of European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017.


2017-09-29

Self-driving buses in Sweden next year?

A self-driving, fossil-free bus. This idea might become reality through a forthcoming collaborative project involving the Swedish National Road and Transport Research Institute (VTI), Linköping University and several other participants. The project group aim...


2017-09-29

New climate-proof solutions for hard surfaces in cities

High-density road infrastructure that emphasise maximum durability and minimum maintenance create inflexible systems, which put increased stress on urban trees and lead to increased risk for flooding. Over the past five years, the ‘Climate-proof solutions for...


2017-09-29

VTI is preparing for automated vehicles

Automation of traffic systems will lead to major changes. The European Union’s (EU) CoEXist research project began in June 2017 with the aim of preparing cities and road operators for the introduction of self-driving vehicles. The Swedish National Road and...


2017-07-05

Vehicle Driver Monitoring: sleepiness and cognitive load

To prevent road crashes it is important to understand driver related contributing factors, which have been suggested to be the critical reason in 94 per cent of crashes. The overall aim of the project Vehicle Driver Monitoring has been to advance the...