Many of the projects and systems we work on are heavily reliant on accurate digital mapping information; for example engineer scheduling relies on accurate location information for the sites and depots to be visited, as well as good estimates of the necessary travel time between those sites. The most comprehensive catalogue of digital map data that we have found is from MapMechanics, www.mapmechanics.com.
They also run very good seminars and workshops on the applications of geographic information systems (GIS) and advanced routing and scheduling systems.