Collapse Dual Lines To Centerline

My first suggestion would actually be buffering the lines, then dissolving the buffers and generate centerlines from those buffers.

If you really don't want to go that way you can try snapping them but there's a high likelihood of the result not being in the middle.

Another thing you can try is dropping them down to individual points and use the NeighborFinder to find the nearest point from the other line. You then have start and endpoint coordinates of the line connecting those points. Create those lines and then create centerpoints for them and connect the centerpoints.

Hi,

If centerline replacer is suffice then you don't need to convert the data to polygons permanently. You can do it on the fly and consider the output as required...