DON'T. USE. SIDEWALKS. NEXT. TO. LOTS.
1. It forces whoever uses your world to use that lot size and that lot size only in that spot
2. It severely limits lot placement, because if you wish to place any sort of lot next to the sidewalk (assuming hte sidewalk makes a square, either by itself or with the road), it is IMPOSSIBLE- absolutely IMPOSSIBLE- to line up edit world lots with all the sides.
3. There is no way for players to remove sidewalks.
Placing sidewalks around lots might look cute for how you want it to look in your game, but keep in mind that it just plain obliterates any and all room for custom lot sizes for everyone else. Make your own version for yourself with the sidewalks, or make two versions. Sidewalks can ruin a world.