  Coverage problem in wireless sensor networks measures how well a region or
parts of it is sensed by the deployed sensors. Definition of coverage metric
depends on its applications for which sensors are deployed. In this paper, we
introduce a new quality control metric/measure called road coverage. It will be
used for measuring efficiency of a sensor network, which is deployed for
tracking moving/mobile objects in a road network. A road segment is a sub-part
of a road network. A road segment is said to be road covered if an object
travels through the entire road segment then it must be detected somewhere on
the road segment by a sensor. First, we propose different definitions of road
coverage metrics. Thereafter, algorithms are proposed to measure those proposed
road coverage metrics. It is shown that the problem of deploying minimum number
of sensors to road cover a set of road segments is NP-hard. Constant factor
approximation algorithms are proposed for road covering axis-parallel road
segments. Experimental performance analysis of our algorithms are evaluated
through simulations.
