Table 2.

Functional description of selected WSN-based ITS traffic control & smart parking applications.

System	Main Purpose	Data Source	Strategy for Vehicle Monitoring	Data Consumer
Work by Yousef et al. [21]	Traffic light control	multi-lane WSN	Count vehicle arrivals and departures	Traffic control Box connected to sink
WITS [35]	Traffic control at intersections	roadside WSN, Equipped vehicles	WSN propagate speed, location provided by vehicles to intersection nodes	Traffic control equipment Connected to intersection nodes
Work by Tubaishat et al. [20]	Traffic light control	Multi-lane WSN	WSN transmits number of incoming vehicles to intersection	Intersection node decides traffic policy and inform nodes at lights
SPARK [29]	Smart parking	Sensor nodes at parking spaces	Periodic monitoring of parking spaces and direct forwarding to unique WSN sink	Guidance & status displays, Remote clients
Work by Benson et al. [28]	Smart parking	Sensor nodes at parking spaces	Periodic monitoring of parking spaces and routing to base station	Remote client
PGS [30]	Parking lot guidance	Sensor nodes at parking spaces	Periodic monitoring of parking spaces and routing to base station	VMS
Work by Tacconi et al. [31]	Street parking/parking lot	Sensor nodes at parking spaces	Check parking availability upon vehicle request	Equipped vehicle