This is a mod that modifies guides in order to reflect the road functionality.   Edge guides always respect the road density: if you're placing a dirt road or a low density street, the edges are at a distance that lets sims build a low density building. If you're placing medium or high density roads/avenues, the edges are at the right distance to build a medium/high density building. If you place train or streetcar rails, the edge guides are near the border.
  As far as road-guides are concerned, this is what happens: whatever road is already placed, if you draw a new road, you'll have the guide at the right distance to build a building on the existing road and one on the new road, both of the density of those roads.
Rails are treated like the edge of the map: if you draw any type of street near a train/streetcar rail, the guides show you the distance for one building of the right density to be built on the new road.   NO-AVENUE-ZONING VARIANT Chose this variant and use it instead of the normal "Functional Guides" if you usually don't zone on avenues. Using this variant, avenues are treated like rails, so guides are shown at a distance where you can draw a street and build a building on the street only. The guides at the edge are near the border.   UDON AND NO-TRAFFIC-LIGHTS COMPATIBILE Use this mod together with latest versions of UDON and Max' no-traffic-lights streets mods to have functional guides with the new streets. It tweaks snap distances so you can actually follow the new UDON guides I added. Warning: UDON elevated and transition ramps/freeway don't show guides. If you use functional guides, but don't have those mods, only the snap distance will be lowered, so you shouldn't have problems when playing online (tell us if you have).
 
I need you to test with other mods to show incompatibilities and needs. Of course it is incompatible with other guide mods.