What to do about Route 57 through the Tateno Gap? The road has been closed since massive landslides did what they do, and the guys in charge seem to have determined that recreating a four-lane road in that area would be inviting more disaster, given the propensity of the slope to slough off into the river below.
Instead, as the Kumanich reports, a proposal has been floated to create a new road originating near the Milk Road entrance that would bypass the gap altogether. This would require creating several kilometers of tunnels, so it is not going to happen soon. However, various entities have come together to investigate possibilities. A map is at the link. - William