Advanced Traveller Information System (ATIS) is one of the important components of Intelligent Transportation System (ITS) Architecture and Cellular Probe (CP) technology is regarded as a promising detection technology for the next generation traffic data collection system. Within the recent years cellular location technology develops very fast. The accuracy of mobile location has been remarkably improved, which provides the possibility of using CPs to give a fairly good estimate of travel speed or travel time in urban, suburban and rural regions. This paper tries to introduce the latest progress of wireless location technology, summarise the existing simulation work and field tests in the academic field and the industrial field, and propose one general system architecture of CP traffic system. Finally several suggestions and recommendations for deploying such an application system are given.