In the case of the city of Patras, the pilot application
was carried out in the framework of the
project JUPITER in 1997. The cost of GPS was
$800 and the cost of the communication device
between vehicle and central station was $2400. The
problems concerning the canyoning effect had been
overcome with the parallel use of sensors and GPS equipment. In the case of the Thessaloniki metropolitan
area, the measurement was made using
two receivers (with an accuracy of 9–25 m) for a
period of two weekdays. The road network was
divided in three discrete categories, taking into
account criteria like the road width, the height of
the buildings etc. As a result of the pilot application,
the signal was available from at least four
satellites in most of the cases while in certain cases
the signals were available from eight satellites.