A side shield for eyeglasses with a spring-hinge temple bar comprising a side wall having a rear edge, front edge, and inside surface. The positioning index light sources become more blurred in order of green and red. A three-dimensional replica of a geographic region is preferably positioned at least partially within the interior space of the enclosure so as to be viewable through the enclosure. In one embodiment, rapid generation of travel times and associated travel sheds may be enabled by performing pre-processing steps on road graph data.