It seems to me that the current signal placement ( at the end of the curve ) would make them hard to see. The overhead signal bridge, while expensive, will no doubt provide a better line of sight for train crews.
Of course, signal bridges are NOT always the better solution. I know a retired BNSF engineer who sez the recently installed intermediate signal bridge in North Auburn, WA., just South of 277th St. overpass, cannot be seen at a distance by southbounds due to the overpass itself.