PleaseDriveFast wrote:If GPS points show a large gap (200ft?) between the perpendicular angle and where cars are actually entering the next segment, then I think we should use the divided AGC construction as shown here. This appears to be about 100ft so it shouldn't create any map problems.

My "magic number" is 75 m (246 ft), comparable to your suggestion (I try to think in meters when using Waze as it's easy to get lengths in meters using WME).

However, there are other considerations besides distance:
- For advanced "offramp", increased potential of conflict with other nearby turns
- Potential confusion if driver can see that the actual road is some distance ahead
- New editors may see and think all such connections should be divided to match aerials
- Waze may snap drivers to the parallel "offramp" and give a bad route

After weeks of turning this over in my head from the perspective of AGCs in general, I've come to feel that this is the solution: we editors should be less concerned with the final instruction and more concerned with the penultimate instruction.

It's nice of course when the final instruction issues in time to rescue a driver who missed the penultimate instruction. But it's not a primary goal that we should sacrifice other things to accomplish.

My primary example is left turns. We editors rarely try the contortions necessary to advance turn warnings for left turns at complex intersections. Instead we assume that the driver will hear the penultimate instruction, and will interpret the final instruction as a simple confirmation once they are already positioned for the left turn. If that concept is acceptable for left turns, it should be OK for right turns as well.

If one abandons the idea of advancing the final instruction as far as necessary to rescue inattentive drivers, many AGC-like constructions become unnecessary. There are still other reasons to have them of course. I've been working on a summary of this that I might offer as an update to the AGC wiki some day.

Being the last editor who touched this (I wonder what I did?), I would actually agree with the 90º AGC construction for these small lots. I would think of these as divided exit/entrances as opposed to on/off "ramp" since ramps are a specific road type.

If GPS points show a large gap (200ft?) between the perpendicular angle and where cars are actually entering the next segment, then I think we should use the divided AGC construction as shown here. This appears to be about 100ft so it shouldn't create any map problems.