AlertC - TMC Location Table

AlertC with TMC Location Table (LT) is a standard for coding locations of road events specified and standardized by TISA. Essentially it is a simplified model that provides location reference to road network built from points and connecting them lines. Each point and line has its own location code, which makes it possible to efficiently decode and visualize content on a map.

OpenLR

OpenLR™ is a method for map agnostic location. It enables systems to communicate location information when they use dissimilar maps.
OpenLR™ is communication channel independent. OpenLR™ requires minimal bandwidth for data communication.
OpenLR™ was designed to transfer location information from traffic information systems used by traffic management centers to portable navigation devices and systems. While it achieves this goal, it is also quite versatile. The encoded locations are typically specific road stretches, lists of connected roads, point locations or areas. Generally, OpenLR™ is unrestricted for encoding the location of traffic information.