We have been doing quality analysis of OpenStreetMap for vehicle routing. The methodology and results for the city of Vienna are described in A. Graser, M. Straub, M. Dragaschnig: “Towards an Open Source Analysis Toolbox for Street Network Comparison: Indicators, Tools and Results of a Comparison of OSM and the Official Austrian Reference Graph” (accepted for publication in Transactions in GIS, pre-print: http://underdark.files.wordpress.com/2013/07/preprint_tgis_foss4g2013_graseretal.pdf)

Thanks, your paper is very interesting for us. I will go more detail trough this and eventually come with additional questions.

Are you aware of the ICT COST Action IC1203: European Network Exploring Research into Geospatial Information Crowdsourcing: software and methodologies for harnessing geographic information from the crowd (ENERGIC). It might relevant to you.

Thanks, we have now in negotiation one project, where (if we will succeed) we will deal with VGI in combination with INSPIRE. SO I hope, that there will be chance cooperate.

Seems that validate VGI data is not easy task. Seems that this could be good, for example, if we will consider some statistical approach

 Hi, I've been looking at different literature about VGI quality - as my current work is strongly related to VGI use. I would agree with Karel, validating VGI is not an easy task and there are different quality approach as well: intrinsic (scientific quality, e.g. spatial accuracy), extrinsic quality (trust, e.g. reliability of volunteer, reputation), and pragmatic quality (usability, fitness of purpose). Look for this paper:

Bordogna, G., Carrara, P., Criscuolo, L., Pepe, M., & Rampini, A. (2014). A linguistic decision making approach to assess the quality of volunteer geographic information for citizen science. Information Sciences, 258, 312-327. doi:10.1016/j.ins.2013.07.013

 In addition, various ways of validating is mentioned in this paper:

Hung, K.-C., Kalantari, M., & Rajabifard, A. (2016). Methods for assessing the credibility of volunteered geographic information in flood response: A case study in Brisbane, Australia. Applied Geography, 68, 37-47. doi:http://dx.doi.org/10.1016/j.apgeog.2016.01.005

However, in my experience, different VGI tools have different ways of validation. 

Thanks for literature list