Outdoor vendors and agencies said the problem needed to be addressed immediately if the medium is to attract more than the 15 per cent of the overall media spend that it now gets.
Shanghai-based Louis Cheng, newly appointed managing director at Portland China (an outdoor specialist unit aimed set up by WPP earlier this year), described the monitoring of traffic at outdoor sites in rural areas in China as "primitive".
"Right now, the research is very much well behind TV. What we have is for metros and subway and this is done by the operator. It's very much an unexplored area ... I suspect there are companies in Europe such as in the UK, which have a more advanced measurement system that could be incorporated here.
"The lack of measurement is certainly worse in the rural areas and these areas are becoming more important for brands in terms of market expansion," said Cheng, who recently replaced Johnny Lo as Portland's MD.
However, outdoor vendor Linkage Media's executive director Jacky Ip expressed concerned about the adequacy of a system to monitor and effectively track the wide variety of outdoor options now available. "The mobile bus body ad is very different from a static subway ad. These would require different monitoring methods," said Ip.