Road transport and traffic telematics - Electronic fee collection (EFC) - Ensuring the correct function of EFC equipment installed behind metallised windshield
Metallised windscreens are produced by spraying small metal particles on one of the glass or plastic layers of
the vehicle’s windscreen. This leads to a windscreen with high thermal qualities, ranging from far-reduced
power consumption by air-conditioning equipment to short times for de-icing.
The production of certain vehicles in Europe which were equipped with metallised windscreens has created a
major problem for the installation and operation of On-Board Units (OBUs) which rely on Dedicated Short-
Range Communications (DSRC) for ITS (as the most-widely deployed DSRC ITS application to date, the
remainder of this report will refer to Electronic Toll Collection (EFC) but the developed solutions will be valid
for all DSRC ITS applications). As is shown in Table 1, windscreen properties have a decisive influence on the
transmission of microwave communication and, for metallised windows, it is essential to compensate these
losses by special measures (Ref 1).
As cars equipped with metallised windows are being shipped in large numbers since July 1997, this problem
needs to be addressed.
It is important to note that the solution proposed is valid for passenger cars and not for vehicles with near-tovertical
windscreens such as trucks and buses.