Vehicular Crowd-Sensing on Complex Urban Road Networks: A Case Study in the City of Porto

The viability of high-mileage vehicles, like taxis, in acting as potential probes for Vehicular Crowd-Sensing (VCS) has been largely confirmed in many experimental studies. However, these studies have been mostly carried out considering data from cities with regular, grid-based, road networks, or by abstracting the road network to a grid of cells. In this paper, we investigate the potential suitability of taxis as probe vehicles, by evaluating the achievable spatio-temporal sensing coverage, computed over real trajectories from a swarm of 100 taxis in the city of Porto (PT). Our results confirm that as few as 100 taxis have the potential to effectively sense complex urban road networks, for many VCS-based use cases. On the other hand, we found that the probing frequency might be inadequate to support use cases requiring higher sampling rates. As a consequence, recruiting more vehicles and/or devising specialized routing/incentitivazion mechanisms might be necessary.