Presentation on theme: "WP 5: Surveys Experience from the process of carrying out the national survey in Germany Evaluation of the process Experience from the focus group, pre-test."— Presentation transcript:
WP 5: Surveys Experience from the process of carrying out the national survey in Germany Evaluation of the process Experience from the focus group, pre-test and main survey Specific issues and remarks: What I learned about the availability of noise cards and software Estimation of a Ldn value from day and night noise levels 3rd Meeting 19 / 20 January 2006, Las Palmas Alexander Gressmann
WP 5: Surveys Final offer of Marmas Bonn could be reduced from € 37.100 to € 36.500, due to: Focus Group at the company´s site in Bonn instead of Düsseldorf, as suggested in the offer Pre-test could also be performed in Bonn, since suitable noise cards have been available General payment conditions of ADM: 50 % when placing the order 25 % with the beginning of the field study (main survey) 25 % after completion and approval Contract finished and all payment settled by December 2005 Subcontract
WP 5: Surveys General experience of teamwork with sub- contractor and the interview process Remarks on the survey design of value-of-time questions Searching for availability of noise data in decibel for urban and rural areas in Germany or possibilities to perform calculations of our own or with the help of other experts of the University of Stuttgart (this took a lot of time until we found a solution for the survey) -> I would be interested how this issue has been solved in the other countries General problem areas to be solved:
WP 5: Surveys Experience from the focus group See my annotations from Budapest; generally similar to other countries The measure of „whispering asphalt“ layer was wellknown to people, since it already has been applied in some areas of Bonn Willingness-to-pay for a continuous payment was zero in most cases The focus group session was the only occasion where we had personal contact to the subcontractor and to the interview process, e. g. where we could see the immediate reactions of IPs
WP 5: Surveys Experience from the pre-test (I) 24 personal interviews conducted in Bonn Overall no problems occurred conducting the interview Conclusion of Marmas Bonn: Version 1 (choice cards) proved to be more practicable and easier to follow than Version 2 (WTP question), which has been considered as too complex and too long
WP 5: Surveys Experience from the pre-test (II) Respondents could not see a relation between the part on noise pollution and the value of time questions To my opinion, WTP for travel time savings for leisure would have produced more meaningful results than travel time savings to work (travel to work is already optimised; all IPs who do not usually go to work by car or public transport have been excluded from this section of questions) – but see the arguments of Laird and Wardman
WP 5: Surveys Experience from the full survey In general it would have been helpful if we had had the possibility to participate directly in the instruction process of the interviewers; this was not envisaged or suggested by Marmas Bonn. Was this possible in the other countries? Some delay and also unnecessary work could have been avoided (BTW, Stuttgart was also originally envisaged as one potential urban area but cancelled since noise data were not formatted optimally). General comprehension problems of IPs, e. g. about WTP questions, have occurred quite seldomly, and not for the value of time demand. Also very few refusals to answer the questions about income
WP 5: Surveys Full survey procedure (I) Randomised personal household survey; 1029 interviews, all quota have been fulfilled On the basis of the noise maps, streets of houses (sample points) have been selected for both categories with a prevailing average (day/night) noise level of at least 65 dB (road traffic) respective 70 dB (railroad traffic). Of these potential sample points those have been finally selected that have resident population. This results in about 40 sample points for each of the 4 subsamples road/urban, road/rural, rail/urban, rail/rural)
WP 5: Surveys Full survey procedure (II) The decision of road vs. railway category thus depended on whether the sample point the IP belonged to has been affected predominantly by road or by railway noise Quota target by equal allocation of the five categories of individual noise annoyance Recruitment of IPs followed the „random route“ technique: Within the sample points, in each third household of all the potential grown-up persons coming into question (>= 18 years) the one was interviewed that was the next to have birthday and permanently belonged to the household. (See also the table of analysable interviews in the annex of the final report) Age = 105 – year of birth (Q39), no matter if IP already had birthday or will reach this age later in 2005
WP 5: Surveys What we learned about the availability of noise cards, databases, and software in Germany (I) Some noise mapping and action planning measures have been done for several cities and regions in Germany, according to § 47a Bundesimmissionsschutzgesetz (Federal Immission Control Act) in its older version. These data have been the results of pilot studies in several cities. There has not yet been a program that covers all areas in Germany, since the EU guideline has not yet been fully implemented.
WP 5: Surveys What we learned about the availability of noise cards, databases, and software in Germany (II) For Germany but also other countries, mainly there are four competing software systems in use for noise mapping: used for sample: CadnaA by Accon/DataKustik Mülheim/R., Augsburg IMMI by Wölfel SoundPLAN by Braunstein + Berndt LIMA byStapelfeldt Bonn, rural areas
WP 5: Surveys Railroad noise, daytime in Mülheim/Ruhr (CadnaA)
WP 5: Surveys Noise databases At the website http://www.laermkarten.dehttp://www.laermkarten.de Augsburg, similar to Mülheim/Ruhr
WP 5: Surveys Railroad noise, nighttime in Bonn (Lima)
WP 5: Surveys For Berlin (the fourth „urban area“ under examination) we used a digital environmental atlas, presented via FIS-broker
WP 5: Surveys For Berlin (the fourth „urban area“ under examination, we used a digital environmental atlas, presented via FIS- broker
WP 5: Surveys Rural areas (municipalities below 20,000 inhabitants) A few pilot projects over Germany, but not sufficient for our random sample Only one area-wide screening of noise exposure exists for the federal state of North-Rhine Westphalia (October 1999) Municipality-related cartography in 1:100,000 scale with a 50 m raster Calculated estimates of noise are conservative, i. e. values are rather too high than too low
WP 5: Surveys Rural areas (municipalities below 20,000 inhabitants) For all municipalities of NRW below 20,000 inhabitants, we made a pre-classification on the basis of the maps, where significant road and/or railroad noise exposure to residential buildings can be identified The 15 municipalities with the highest noise exposure in each of the two categories have been used for the rural sample
WP 5: Surveys Estimation of Ldn from the day and night levels (I) Since noise level data are not available for Germany in an averaged way but only as separate values for daytime (6 – 22 h) and night (22 – 6 h), we had both values coded in the survey (Q 47A and Q 47B instead of one variable Q 47 as specified in the codebook). L dn = This L dn with the data of the German survey should be similar to the L den without the need to make further sophisticated assumptions.
WP 5: Surveys Estimation of Ldn from the day and night levels (II) Using this formula, we generated an additional column Q 47C that can be used for further statistics. See that we have the original data only in classified 5 dB values. The original value of Q47A and Q47B denotes the upper bound of the interval. Therefore we reduced both values in the formula by 2.5 dB to have the midpoint of the interval as average dB value.
WP 5: Surveys Estimation of Ldn from the day and night levels (III) – Nonlinear relationship
WP 5: Surveys Estimation of Ldn from the day and night levels (IV)