[OSM-talk] magical road detector to play with

[Alan Mintz]

Here's another example where it fails to spider because it doesn't want to 
cross, or even get close to, paved dips at intersection boundaries, no 
doubt because it thinks they are sidewalks. That should probably be a 
pattern it is sensitive to (roadColor-borderColor-roadColor) and allow it 
to go through it. It will occasionally generate non-existing intersections 
where a perp intersection is separated only by a single sidewalk, but these 
are rare IME.

Also note the way (33.4587097, -117.1022644)-(33.4588280, -117.1024399). 
Not sure what this was supposed to be. Maybe the short dead-end heading ESE 
from near the second point?

Note that it doesn't complete the road between the two given points, 
despite the fact that they are within about 10cm of the centerline 
endpoints (pt1 the center of the circle that fits the cul-de-sac and pt2 
the intersection of the two centerlines).

Future improvement thought: when it sees the road flare left and/or right 
just before an intersection, ignore the flare and draw the intersection 
where it would be if the corners came to right angles. This will prevent a 
lot of deviated intersections like the one at (33.4588280, -117.1024399), 
reducing complexity and improving appearance.

http://3667a17de9b94ccf8fd278f9de62dae4.cloudapp.net/DetectRoad.svc/explore/?pt1=33.4583630,-117.1031114&pt2=33.4578704,-117.1037238&bbox=33.467,-117.109,33.452,-117.091

--
Alan Mintz <Alan_Mintz+OSM at Earthlink.net>