Ambient intelligent services are a set of services that are inside a specific zone provide seriveces for the users inside that area. Streets are one of the most important ambient intelligence environments in the cities. A smart street refers to a street which is able to provide its users relevant and proper services according to their conditions. Information services are one type of ambient intelligent services. Commercial messages of shopping centers, traffic statistics of various urban districts and police announcements from mobile or static urban stations are all important examples of urban information services. Since most service users, such as vehicle drivers, are constrained to move only on a network, service sites should be defined on the network as well. Determining the service provision region especially on the streets network and particularly for vehicles is an important issue that has not yet been studied in ambient intelligence. Utilizing the Network Voronoi Diagram (NVD) is one of the spatial analyses in Location Based Services, especially in the streets network; since adjacency to service centers should be considered in regard with the distance on the network. In the present study, a method for providing vehicles on the streets network with information services has been proposed. In this method, factors such as the adjacency of vehicles to services sites, servicing time and vehicle movement quality direction are taken into account. The obtained results from implementing the proposed method in one district of Tehran indicate 68 percent  satisfaction with the system performance in utilizing network spatial analyses.