Paths (GTA V)

Overview
Paths are nodes (single points) and links (connections between two points) on the game map. In Grand Theft Auto V, they can be found in a file named paths.ipl. Depending on your version they may also be found in your GTA V executable folder under common.rpf\data\levels\gta5\paths.xml Overall, paths in GTA V are similar to paths in GTA IV and paths in GTA SA. In total, GTA Vs paths.ipl' contains 74,530 nodes and 77,934 links. Each node has 22 values (x, y, z coordinates and 19 flags), each link has 6 values (2 node ids and 4 flags). Coordinates are floats, representing meters, with North Yankton included in the south-west corner of the map, and node ids are integers, referencing index positions in the node list. While the meaning of several flags has been discovered, the purpose of most of this data is still unknown.

Grid Squares
In addition to the paths files, GTA V paths are also organized as grid squares. common.rpf\x64e.rpf\levels\gta5\paths.rpf (RPF files can be opened using tools like CodeWalker or OpenIV)

The grid squares are arranged as shown here, with each grid having its own area ID.

Analysis
For both nodes and links, the data for each of their flags can be plotted as a map, with different colors for different values. A set of such images is publicly available (ZIP, 23 PNGs, 42 MB).

Node flags:

0: 0 (enabled) or 1 (disabled) 1: 0 (land), 1 (water) 2: unused 3: 0, 1, 2, or 3 - Speed 4: 0 (normal), 2 (unknown), 10 (pedestrian), 14 (interior), 15 (stop), 16 (stop), 17 (stop), 18 (pedestrian), 19 (restricted) 5: density (divided by 15) 6: street name hash 7: 0 (road) or 1 (highway or interior) 8: 0/1 (bool) no gps 9: 0/1 (bool) tunnel 10: unused 11: 0/1 (bool) cannot go left 12: 0/1 (bool) left turn only 13: 0/1 (bool) off road 14: 0/1 (bool) cannot go right 15: 0/1 (bool) no big vehicles 16: 0/1 (bool) indicate keep left 17: 0/1 (bool) indicate keep right 18: 0/1 (bool) slip lane

Link flags:

0: width 1..10 or -1 or -10 1: lanes in (lanes from source to target) 2: lanes out (lanes from target to source) 3: 0 (unknown), 1 (unknown), 2 (unknown), 3 (unknown), 4 (unknown), 5 (unknown), 8 (lane change), 9 (lane change), 10 (street change), 17 (street change), 18 (unknown), 19 (street change)

lanes_in and lanes_out dictate whether a road is one way or two way. By default lanes_in is 2, and lanes_out is 0. This is a one-way, 2 lane road in the direction of source to target. A road with lanes_in 1, lanes_out 1 is a 2 way single lane road etc. etc. Maximum lanes is 6.

Trivia

 * It is likely that Taxis use the paths when driving the player around. This would explain why the follow certain paths which are not visible on the map or in-game when traversing a mountain or beach.