Workshop Report

Title:
Report from the Workshop held on 1 August 2006 at the premises of the European Commission (Charlemagne Building)

Date: 3 Aug. 2006

Drafted by         
Malene S Jespersen, Anne Ohm (COWI),
Luc Goubert, Guy Descornet (BRRC)

Background 

The workshop was organised as part of a contract implemented by COWI and BRRC for DG-ENV. The purpose of the contract is to investigate the opportunities and feasibility of possible acoustic classification systems for road pavements.

The one-day workshop was organised by COWI and BRRC. It was held on the 1st August 2006 at the premises of the European Commission (Charlemagne building). About 35 stakeholders participated in the workshop (see attached list of attendees).

Two draft reports had been prepared by COWI and BRRC prior to the workshop. The two reports aimed to provide a review of current research and literature into the subject including an overview of existing classification systems, and to assess costs, benefits and cost efficiency of now noise road pavements respectively.   

At the workshop, the conclusions of these two reports were presented and discussed. Also, representatives from selected countries were invited to present their experience and views. Similarly, representatives from FEHRL and from ERF presented their experience and viewpoints.

Web-site        

A web-site has been established that provides all information on the workshop (http://www.cowiprojects.com/noiseclassification). Here, one can find all information on the workshop including the above reports, power point presentations, list of participants, programme for the workshop and links to other relevant web-sites.

Structure of this report         

This report provides a summary of the presentations and key points raised and discussed during the workshop.

Workshop programme          

The workshop programme is duplicated below. The power point slides that accompanied each presentation should be considered as part of this report. Here, we provide an overview of the key messages and essential conclusions from each presentation together with the possible specific points of discussion.

1     Introduction

Essential messages              

David Delcampe introduced the legal and policy context of the workshop, and raised five essential questions to keep in mind during the discussions of the workshop:

1  Can low noise road surfaces significantly and beneficially reduce road traffic noise in addition to noise limitation of vehicles and tyres or other abatement measures?

2   Should road surfacing be locally considered under noise action plans due by D. 2002/49/EC?

3   Can public procurement authorities specify acoustic performances of road surfaces? Can they check the acoustic performances of road surfaces once laid down?

4   Are there common standards allowing that such specifications are set and checked while ensuring healthy competition of road surfaces providers?

5   Should the Commission mandate the CEN with a view to develop such standards? To which main aspects should the EC pay attention in its mandate to CEN?

The scope of this workshop is right, because the appropriate policy framework is indeed in place. Needs for action to reduce road traffic noise at source, including tyre-road noise, are pointed out by essential EU policies, e.g. the review of the Common Transport Policy, the Thematic Strategy on Urban Environment, the Ambient Noise Directive and its forthcoming review, the Sustainable Development Strategy and the 6th Environment Action Programme.

Therefore, according to David Delcampe, there is now need for pragmatic solutions in order to support the implementation of the mentioned policies and strategies. Low noise road surfaces appear to be amongst the appropriate actions to be envisaged by the noise action plans required by the ambient noise legislation. Common measurement methods aimed at determining acoustic characteristics of road surfaces as well as common acoustic classification of road surfaces may be appropriate instruments in order to implement lower noise road surfaces, and this workshop can assist to shed light on the answers to the five key questions formulated by DG ENV in this respect.

2     What is low noise road pavement?

Key messages                     

Luc Goubert presented the technical background about low-noise pavements.

Tyre/road noise determines vehicle noise at speeds above 40 km/h (for cars). The generation mechanisms are rather well known. The road surface influence on vehicle noise depends on its texture profile spectrum, sound absorption curve. By optimizing those characteristics, presently available low-noise pavement technology already yields very significant noise reduction. The pavement stiffness can play a role if it is of the order of the tyre stiffness. An experimental poro-elastic road surface made of scrapped tyres promises even better noise performance.

3     Costs, benefits and cost-effectiveness of low-noise pavements

Key messages                     

Anne Ohm pointed to the basic precondition for advancement of classification of low noise pavements is that it can be justified that low noise pavements are amongst the cost-effective means of noise abatement. With respect to harmful effects of noise one distinguishes between annoyance and health effects. The associated costs consist of direct financial costs for society such as medical costs and lost productivity, as well as indirect costs such as annoyance and reduced quality of life.. Results from the Danish Noise Strategy (2003) indicates social health costs to be in the order of 80-450 MEUR per year involving 800-2,200 people hospitalised and 200-500 premature deaths due to the increased risk of hypertension and heart diseases, caused by road traffic noise. If one includes annoyance costs the estimate amounts to an annual 1.2 billion €.

Two main studies in this field are the Silvia project and the Danish Noise Strategy project. The methodological approaches of these two studies are quite similar relying on a base scenario and alternative scenarios. The factors that influence the noise level are assessed and account is taken of side effects such as safety, air pollution and travel time. Benefits are calculated using a unit cost of noise.

Calculations base don the Silvia methodological framework clearly indicates that low noise pavements are cost effective compared to barriers and insulation in those cases where there are dwellings at both sides of the road. Moreover, a Silvia meta-analysis of 18 studies shows that there are no significant differences between porous asphalt and dense asphalt with respect to safety, rolling resistance and fuel consumption. Low noise pavements are optimized according to macrostructure and porosity which do not significantly influence on these factors.

Noise abatement measures analysed in relation to the Danish Strategy includes low noise pavements (two layer and thin layer), barriers, insulation, low noise vehicles, low noise tyres and speed reduction. A dose-response function between road noise and heart diseases was established for the first time and used for calculating health costs and a unit cost of noise. Ranking the cost efficiency of the analysed measures clearly points to low-noise pavements to be among the cost-effective means of noise abatement independently of the unit cost of noise. This conclusion is independent of the assumption on the unit cost of noise. Moreover, most noise abatement measures show a positive cost-benefit ratio, i.e. an economic surplus, when comparing the costs and the benefits (reductions of annoyance and health effects) of the measures.

An important prerequisite for these conclusions is that replacements of pavements are made at the ordinary time of replacement. The reason is that it is only the additional costs of low noise pavements compared to those of ordinary pavements which are of relevance to the comparison.

Comments and questions

Ulf Sandberg pointed to the fact that facade insulation also has an energy saving effect, which needs to be taken into account when calculating the net costs of this intervention and to the fact that insulation only reduces noise inside the dwelling. Also, he noted the importance of the visual intrusion caused by noise barriers, which is not always acceptable.

Johan Lang pointed at the importance of assumptions made with regard to lifetimes of noise abatement measures considered in the comparisons. Answer: all lifetimes for road pavements have been set at 15 years, and to 7.5 years for the top layer. The possible implications (higher costs) of shorter lifetimes for low noise pavements than for other pavements have not been analysed in this study.

4     Current status on classification systems

Key messages                     

Guy Descornet presented the state-of-the-art of classifying road surfaces with respect to noise.

Fourteen different classifications used in European countries have been identified. They apparently have three kinds of applications, namely: 1) guidance for decision-makers, 2) correction terms in calculations and 3) contractual specifications. But the objectives and legal status of most existing classification systems are not clear in most cases. They appear to be generally not comparable and not exportable across borders. A striking finding is that same types of road surfaces do not have the same acoustic properties (noise reduction) or even have opposite influences in several classification systems. The reasons for their inconsistency are numerous; namely:

• Reference surfaces not really identical

• Surfacing types not comparable:

o        Country-specific types

o        Same name for different materials

o        Different names for same (proprietary) product

• Only in certain cases, corrections take account of one or several of the following:

o        Traffic speed

o        Vehicle categories

o        Surface age

o        Material grading

o        Road gradient

• Use of different measurement methods

 At the EU level, several initiatives have dealt with acoustic characterization of road surfaces.

TRL and TüV made a report[1] for WG 8 on road traffic noise (DG ENTR Working Group) titled ‘Integrated assessment of noise reduction measures in the road transport sector’ (2003). The work carried out  was based on TraNecam (developped for German UBA) and Rotranomo models in which a set of road surfaces are described in ROTRANOMO model[2] (funded by 5^th Framework Research Programme) according to their acoustic performances. 

Another initiative is Harmonoise project[3], which developed calculation methods in order to support strategic noise mapping. The calculation method for road traffic noise provides a model which allows taking account of road surfaces influence on the whole road traffic noise. It also provides a set of correction factors for several types of road surfaces.

 Two countries have developed their own procedures for labelling and conformity of production checking, namely UK and The Netherlands.

 Harmonization seems necessary and timely, and the key question is rather how to achieve it?

 5     Elaborating procedures for CEN standards

Key messages                     

Amilcar Da Costa provided an overview of the working procedures of CEN in order to illustrate how the standards are typically developed, endorsed and put into use.

Under the Construction Products Directive (CPD), there is a time lapse of 21 months between the availability of a harmonized construction product standard and its mandatory implementation: 9 months (the EC has 9 months to cite the title of the EN in the OJEU) to allow the Member States to adapt the National regulations to accept a CE-marked product in their markets and a period of co-existence (National standard and new EN living together) of 12 months to allow the relevant manufacturers to get rid of non-CE-marked stocks. The product standards developed und the CPD are mandatory. According to the CEN rules the European Standards are developed within a period of three years. Exceptionally and for well justified reasons (research needs etc.) the development may take a bit longer.

The development of standards is a continued process, and the presenter expressed the view that rather than to go for the perfect solution, emphasis should be put on developing a feasible and operational first generation of standards, which can subsequently be improved.

Mr Da Costa further convened information from Mr Michel Boulet (The Chairman of CEN/TC227/WG5), who was unfortunately not able to attend the workshop. Provided information from Mr Boulet is summarized below:[4]

 •            Working group CEN/TC227/WG5 “Road surface characteristics” already considered the topic and concluded to the timeliness of starting to prepare a ‘method aiming to establish a classification of the acoustic properties of road surface materials in place on the road. According to Mr Boulet, the method should be based on SPB (EN ISO 11819-1) and CPX (ISO 11819-2) test methods.

•            Mr Boulet has submitted accordingly to CEN/TC227 at their recent plenary meeting (Vienna, Austria, 8-9 June 2006) a new Work Item following the line above.

•            A working draft could be finalised by January 2008 by taking advantage of European project SILVIA, the existing expertise in the EU Member States and the possible completion of the CPX standard under ISO/TC43/WG33.

•            Mr Boulet solicits the agreement and support from the European Commission on the proposal for a new planned standard presented by CEN/TC227/WG5, the status of which will remain to be defined (as a preliminary stage, an “Experimental standard” or a “Technical specification” could be desirable)"

•            A recommendation from Mr Boulet regarding the objectives to assign to that project:

o    To design a method reasonably relevant and reliable (avoiding excessive, useless perfectionism), but, above all, simple, practical, cheap and easy to implement.

o    To assess whether it would be better to separate classification method and conformity checking method: related objectives don’t seem necessarily similar to Mr Boulet.

 Comments and questions

Anne Ohm asked whether it is acceptable to issue a standard that is “not yet very precise” as A. Da Costa seemed to suggest for gaining time. In reply, A. Da Costa answered that a standard is always based on the currently available best practice but it can be revised and improved if required by experience.

 David Delcampe asked what the differences are – with regard to the consequences for Member states and public procurement authorities - between non harmonized and harmonized standards. Mr. Da Costa stated that a harmonized standard is a standard developed under a mandate from EC/EFTA and cited in the OJEU. A non-harmonized standard is a voluntary standard that has not been the subject of a mandate and consequently not cited in the OJEU. Under the Construction Products Directive, only the product standards are cited and become mandatory, unlike the standards developed under the New Approach Directives.

6     Does a CEN classification make sense?

Key messages
         
Guy Descornet explained that Belgian and French databases show that even well-defined surfacing materials exhibit a very large scatter of their noise performance in terms of pass-by levels. The reason is that the acoustic performance of a road surface is not only determined by its compound. There is a significant influence of the laying process and circumstances, which will determine the most noise-relevant surface characteristics, namely texture and porosity. So, a classification based on pavement “types” is not reliable enough, namely for use in procurement contracts.

That is why the SILVIA project, inspired by the Dutch and British procedures, developed a classification scheme associating a type approval and a conformity of production testing procedure for well identified products. Two alternative procedures are proposed. Procedure n°1 associates an SPB measurement and a CPX measurement. Procedure n°2 associates the SPB measurement on one hand and a set of “proxy” physical measurements of the noise-relevant pavement characteristics on the other hand. The latter characteristics are texture profile spectrum and sound absorption spectrum, plus stiffness in case of an elastic surfacing.

G. Descornet reviewed the different measurement methods and the state of standardization of them. Except for mechanical impedance (stiffness), all necessary measurement methods and equipment are available and standardized or in the process of being standardized by ISO.

An experiment made by the Dutch project IPG showed 2 to 3 dB(A) differences between the same surfacing laid by the same contractor at different places, which sets a limit to the reproducibility of a given surfacing “product”.

In conclusion, the following recommendations were made:

•    Standardization:

       -       Take over ISO CPX as CEN standard when finalized

       -       Take over ISO SPB as CEN standard when revised

       -       Take over ISO Megatexture as CEN standard when issued

       -       Take over ISO Sound Absorption in situ as CEN standard.

       -        Develop a CEN std. on classification method (for noise calculation, noise mapping)

       -        Develop a CEN std. on labelling / type approval procedure
                (for contractual specifications)

       -        Develop a CEN standard on COP testing procedure (for contractual specifications)

•       Research:

       -        Support the development of Poro-Elastic Road Surfaces (PERS) in Europe

       -        Taking advantage of experiments with PERS, develop and validate a
                measurement method for Mechanical Impedance

       -       Complete the SILVIA model for surface characteristics influence on noise
               by including MI with a view to the next generation of CEN standards

Questions and comments

David Delcampe asked further information with regard to Mr Descornet’s reaction on Mr Boulet’s suggestions. G. Descornet answered that in his opinion, the CPX measurement method is neither reproducible nor representative enough for the development of needed standards. Other aspects and methods should be considered for COP testing. There is no precise relation between the CPX and the SPB method, but it is possible to predict the SPB level starting from the proxy parameters (texture and absorption). There is also a reproducibility problem between the different existing CPX measurement systems. Therefore in SILVIA a certification procedure for CPX is been foreseen in order to minimize the spread. Moreover, results from European research on rolling noise could be beneficial to the preparation of the standards needed and therefore need to be taken into account.

Cristo Padmos remarked that SILVIA Procedure n°2 needs the texture profile to be “enveloped”. That procedure is not easy and should be validated. G. Descornet answered that a computer calculates the envelope in microseconds. He – together with M+P – described and justified that procedure in a paper several years ago. It has been further validated theoretically by SILVIA (INRETS model).

 Ulf Sandberg noted that there is a scope for improving the CPX method as well. The method recommended by SILVIA could be a good step forward with such improvements (e.g. with regard to the handling and storing of reference tyres), and that it might be too premature to go solely for the method proposed by the presenter. This point was further elaborated upon by Mr Georges Dimitri who noted that reference tyres must be continuously available and be acquired in smaller quantities rather than batches to allow for proper handling/storage.

Christo Padmos mentioned the currently initiated large scale project funded by IPG (Dutch Innovation Program) to, among other things, improve the CPX method.

Hans Van Leeuwen noted that SPB measurements are also problematic. The requirements with regard to the number of vehicles to be selected, the location of the measurement, and the set height of the microphone position are very difficult to comply with, and further it is questionable whether the use of peak values only provides the right outcomes. He states that the use of SEL would be better than the actual L_Amax. This is one of the reasons for the low correlation between SPB and CPX values[5]. Last, the method is very resource-demanding. Answer: the presenter agrees and notes that this is exactly one of the key reasons why the method is not recommended to be used in regard to conformity of production, but only in regard to the labelling of the products. Concerning the alternative use of SEL, there is no need to switch to SEL measurements because there is a good correlation between SEL and L_Amax.[6] 

Steve Philips noted that the observed wide discrepancies between tests of similar constructions would most likely have been smaller had constructors been asked to reproduce according to their own recipes rather than a pre-scribed recipe.

7      Experience and views from national road or environment administrations

The below provides a brief overview of the contents of the individual presentations.

7.1     Sweden (Johan Lang)

It was explained that an overall objective has been set whereby the number of people exposed to indoor traffic noise exceeding the set guidance values must be reduced by 5% comparing 2010 and 1998. Road noise is seen as a critical and increasing problem.

Sweden has focused mostly on immission, but is now shifting focus towards emissions, and the Swedish pavements are among the noisiest in Europe. In defining measures in this regard, attention is focused on low-noise durability, lifetime, cost-benefit motivated justification of actions, and other important effects (particles emissions, traffic safety issues, and rolling resistance). Road noise monitoring and performance contracts are essential means to use.

A European standard is a way to coordinate the many recently completed and ongoing efforts - and it is time to move in this direction. Standards should consider/cover:

•            CPX and SPB methods

•            Megatexture

•            Sound absorption

•            Acoustic classification (labelling and conformity of production)

•            Mechanical impedance

7.2     Poland (Dominika Jezierska)

No mandatory systems are in place in Poland. Three institutes work with measurements (using SPB and CPX) and the development of classification systems (TUG, TUB and IBDiM).

A classification system has been developed by TUG/TUB. IBDiM has undertaken measurements and categorised existing road pavements according to the results of the measurements and according to this system. Among the pavements tested and included into the classification system are newer commercial products (GUFI and COLSOFT).

Georges Dimitri suggested to include the category “very quiet road surfaces" in order to stimulate competitiveness and scientific development. In reply, it was explained that only existing road surfaces are considered. Steve Philips noted that COLSOFT is a proprietary name, and posed the question on how Poland will encourage companies to enter the Polish market? Answer: all new products on the market will be investigated. David Delcampe asked about the legal status of the Polish classification system: Answer: it has no legal status

7.3      Germany (Wolfram Bartolomaeus)

There are no requirements yet in place in regard to type approvals of road surfaces, and it is a discussion point in Germany.

W. Bartolomaeus argues that, if one has to take into account the reproducibility range of, say, 5 dB(A) of a porous asphalt with a view to guaranteeing a noise reduction of 5 dB(A), one should impose in a contract a 10 dB(A) measured reduction! This is hardly acceptable. Therefore, Germany plans to make use of the method recommended in the SILVIA project, and considers the reduction of variances observed with regard to PA as one of the important future challenges. A research programme in this regard will be initiated very soon. Practical testing of the procedures and methods proposed by SILVIA is necessary.

In reply to a question put forward by Luc Goubert, it was explained that the inclusion of the standard variation into the procedures is a legal requirement which calls for a 90% confidence interval.

7.4     France (Guy Poirier) 

Existing requirements in France relate to the noise levels on the frontage of buildings. There are no time limits, and in situ measurements are used. The acoustic characteristics of the surfaces are not yet taken into consideration because of two major difficulties: degradation of acoustic performance while aging and high variation of the observed acoustic performance for a given surface.

An experimental process is ongoing in France in collaboration with the French Road Institute relying on CPX (the standardisation under development by ISO and making use also of an operating procedure developed nationally) and on SPB (ISO standard).

The objectives of the efforts are to allow for inclusion of acoustic specifications in contracts in order to provide for proven and durable efficiency of low-noise surfaces.

It is appropriate to, at a European level, implement the required experimental testing and launch necessary research programmes with a view to reaching standards based on validated methods and starting off from an experimental status. Standards should be easy to operate, cost-effective and reliable.

In reply to an inquiry put forward by Guy Descornet on why France developed experimental standards along with the implementation of the SILVIA project, it was argued that it is not a matter of a new standard, but of experimental testing due to lack of existing CEN method fulfilling the same objective.

David Delcampe requested that the Commission be further informed on the context of the French draft method.

7.5     Denmark (Jørgen Kragh)

Denmark is implementing, on an experimental basis, a 1st generation system for inviting tenders and documenting noise reduction of wearing courses. The system is elaborated in a forum comprising the various important stakeholders and relates to the construction and measurements of specific sections. The measurement method used is CPX modified according to the Danish context, and five groups/classes of wearing courses have been established ranging from A (particularly good) to E (no noise reduction). Speeds are established at 50 km/h and 80 km/h. The CPX proves to match quite well with selected SPB measurements.

8     Views and perspectives from other stakeholders

8.1     European Road Association (Antonio Hidalgo)

The presentation emphasised the importance of guidelines and standards in regard to developing efficient noise action plans. Also, guidelines and standards play a crucial role in not only developing the plans, but also in the selection of products, the realisation and check of installed solutions and in regard to ensuring long termed performances.

The presentation illustrated that it is indeed a substantial challenge for Member States to develop the strategic noise maps and to elaborate the consequent noise action plans. With reference to the ongoing work in regard to noise reduction devices (CEN TC 226 WG 6), similar effort should be devoted to road surface standards.

8.2     Organisation of European National Road Research Centres (Steve Philips)

Joint performance based specifications are vital to provide for better performance, continued stimulation of innovation and a sound European competition, and enable road authorities to set objective criteria for procurement purposes and targets. Today, Member States develop their own divergent systems.

However, to reach this, a number of challenges lie ahead and must be recognised among which are:

•             As a result of Member States' individual efforts, national databases are established, and these databases can become useless once a common classification is put in place.

•            Classifications must be framed with a view to future developments - cf. the experience from the vehicle industry where industry has complied with the requirements put forward, but conditions changed so that noise reductions have not been observed

•            A good classification system must be repeatable (same measurers should obtain similar results at all times, can be affected by e.g. meteorological conditions, site conditions and variation in traffic), reproducible (subsequent examiners should find similar results as the first no matter the country - requires a harmonisation of the test parameters) and representative (relate to actual nuisance at the surrounding dwellings)

There is a need for a clear roadmap setting out the path towards a joint system.

9     Discussion points

It is stated that the time is mature for a standard and that we need the best standard according to the actual technology. We have to accept that the precision is limited and it should be mentioned (e.g. ± 3 dB(A)).

Status for ISO WG33 progress on CPX standard. The reference tyres constitute the main problem and this issue is the main problem why no result can be expected until some time in 2008. Approximately one more year is needed for the standard as such, whereas an additional half a year is needed to address the issue of reference tyres. One option is a ASTM reference tyre. If, by December 2007, results point at certain reference tyres, it can become a standard quickly - maybe at the beginning of 2008. Specifications need to be made of the properties of the reference tyre.

Mr. Da Costa stated that the adoption of an ISO standard by CEN could be done by applying the Unique Acceptance Procedure (UAP) of 5 months. If required, the CEN Technical Committee could decide by passing a resolution.

Mr. Da Costa said that the earlier a mandate is given to CEN for the development of the classification standard the earlier a standstill would be put in place and this would prevent the development at National level of possibly diverging situations.

Georges Dimitri asked whether it is possible to have a parallel development of the same standard by CEN and ISO. Mr. Da Costa answered that according to the Vienna agreement either ISO or CEN leads the process, not both. As ISO is already working on the standards, it is logical that ISO continues to do so. Ulf Sandberg said that CEN members are invited to give their comments to the concerned ISO group. Mr. Dimitri stressed the need for a proper funding of the normalization work. Ulf Sandberg said that he agrees with Mr. Dimitri. The development of the “robust CPX” had to be delayed due to lack of funding.

Progress on improving the SPB method? The current version is about to be adopted by CEN/TC227. It is currently being revised by the ISO group led by U. Sandberg.

10     Conclusions and future steps

In summing up, David Delcampe revisited the five key questions put forward in the introduction session, and concluded as follows:

1           Can low noise road surfaces significantly and beneficially reduce road traffic noise in addition to noise limitation of vehicles and tyres or other abatement measures? Conclusion: yes.

2           Should road surfacing be locally considered under noise action plans due by D. 2002/49/EC? Conclusion: yes.

3           Can public procurement authorities specify acoustic performances of road surfaces? Can they check the acoustic performances of road surfaces once laid down? Conclusion: surprisingly many acoustic measurement methods and classification systems already exist in Europe, but they are neither harmonised nor comparable. Moreover some systems refer to commercial product and are not technologically neutral; or introduce restrictions onto the access to national markets for low noise road surfaces.  

4           Are there common standards allowing that such specifications are set and checked while ensuring healthy competition of road surfaces providers? Conclusion: The workshop has clearly pointed to the need in Europe for harmonised standards if one wants to foster healthy competition. ISO and CEN standards already exist which may support the elaboration of the needed CEN standards and be beneficial for public procurement authorities.

5           Should the Commission mandate the CEN with a view to develop such standards? To which main aspects should the EC pay attention in its mandate to CEN? Conclusion tends to be positive. Ad hoc working group under CEN has already concluded that such standards are desirable and should be supported by the Commission. The workshop has also pointed to the need to strike a delicate balance between many diverging technical views and current procedures. Availability at short term of CEN standards is desirable but should not prevent further improvements in order to take advantage of technical and standardization progress and innovation. This calls for a careful design of a possible CEN mandate fostering a progressive and open approach, as well as for appropriate support from the part of the Commission.

11     Practical matters

Comments and further inputs in regard to the workshop and the reports prepared by BRRC and COWI in support of the process must be delivered by e-mail before 4th August in order for them to be taken into account in the finalisation of this contract.

Comments, reflections and further inputs are welcomed by the European Commission (David Delcampe) and will, as appropriate, feed into the further work by the Commission on the issue.

12     Written contributions

Some workshop invitees provided written contributions before or immediately after the workshop. These contributions are:

Ulf Sandberg, VTI/Chalmers University, Sweden: Comments related to the workshop in Brussels 1 August 2006

Hans Van Leuven, DGMR, Some extra remarks after the workshop

R. Bull-Wasser, Federal Highway Research Institute, Germany and adjoining message from Mr Wolfram Bartolomaeus (same)

Eva Barnos, Contribution from Rotterdam as reaction to the invitation to Eurocities

Christos Padmos, Ministerie van Verkeer en Waterstaat, Our point on road classification

The French General Roads Directorate's Opinion on the euorpean Standardization Process

Experimental program aiming at characterizing, checking and monitoring in situ the acoustic performances of road surfaces

Contributions of the chairman of TC227/WG5, Mr Michel Boulet