  This study aims to investigate the variability of exposure levels among road
users generated in a realistic urban scenario by Vehicle-to-Vehicle (V2V) and
Vehicle-to-Infrastructure (V2I) communication technologies operating at 5.9
GHz. The exposure levels were evaluated in terms of whole-body Specific
Absorption Rate (wbSAR) [W/kg] in three different human models, ranging from
children to adults. We calculated the electromagnetic field exposure level
generated by V2V and V2I using raytracing and we assessed wbSAR resulting in
urban exposure scenarios with an increasing number of transmitting antennas.
Whole-body SAR was generally very low, on the order of 10^-4 W/kg. The maximum
wbSAR, of 4.9x10^-4 W/kg, was obtained in the worst-case exposure condition
comprising more than one transmitting vehicle and was found in the adult model
for a distance within 10 m from the transmitting cars. We found that the height
of the human model highly impacted the exposure level. Namely, the child (which
is the shortest human model) was generally much less exposed than adults. All
the wbSAR values found by varying the number of transmitting antennas, the
distance of the road user from the antennas, and the type of human model (adult
vs. child) were very well below the limits set by the ICNIRP and IEEE
guidelines of 0.08 W/kg for human exposure in the 100 kHz - 300 GHz range.
