For the most part, images should be self-explanatory, but there are several things you need to keep in mind in interpreting the numbers in the images.
1. Numbers in images are in [Blizzard Seconds], not real seconds.
2.
Starting point at each base is always south side of CC/Hatchery/Nexus. This is because this research was originally done for my Zerg drone scout timings. (larvae always spawn at south side) Most maps today are symmetrical, but distances to first ramp are different from one starting position to another because of this.
3.Allow for a margin of error. No external program was used to measure all distances. In fact, I just sent a drone while watching the timer. 30seconds is somewhere between 29.1-30.9 sec or so, but not 35 sec for sure.
4.On maps where there is a clear choke point or another ramp in front of natural base that is reasonably far enough from the ramp at main base, (Shakuras Plateru for example) distance to each ramp/choke is shown in images. On other maps where natural's choke point is close to the main ramp, (Daybreak for example) distance is shown only to the main ramp.
5.Units can take multiple paths. Paths for A->B and B->A are different on some maps and the directions are shown with arrows.
6.Green lines instead of yellow lines mean no close position spawns. Whenever a scouting worker arrives at an intersection with a green line for the first time in game, the path in green line should not be taken because there is 0% chance your opponent’s base is there. Only after scouting 1 base, should the scouting worker take a green path to scout 2nd possible place for opponent’s base. In other words, when a worker takes a green path, you “already know” where your opponent is.
7.Blue lines are used for paths that are blocked by destructable rocks at start.
8.Travel time for 2.25 and 1.88 are not from direct test results but calculated from 2.81 results. +25% for 2.25 and +50% for 1.88 from 2.81 results.
9. Stalker and Zergling have 2.95 movement speed, which have about -5% traveling time from 2.81 results. Rounding and measurement margin of error makes -5% decrease fairly insignificant. I've decided it's not worth my time to make another images just for stalker/zergling because the difference is 2 sec maximum even for the longest distance. Without decimal number level accuracy, it is almost pointless. Just subtract 1~2 seconds from 2.81 worker speed images for long distances if needed.
10.Marine=2.25 applies to all units with 2.25 movement speed. Units' movement speeds are for those without any upgrades = roach without glial reconstitution, zealot without charge etc. Same for other movement speeds.
11. All images are from Liquipedia page
http://wiki.teamliquid.net/starcraft2/Maps#1v1_2Some images are different from actual ladder maps of those used in tournaments. However, the test was done with actual maps, so the results can be trusted regardless of the images that do not match exactly to ladder/tournament maps.