this would result in a ionike geary, and because of sewer utility, it would require a much deeper tunnel under the train tracks that exists, for example, at geary boulevard. we have been concerned about t yation w was -- gradation that was the proposal. we obviously had to look at trade offs. i won't go through this. costs are an issue, connectivity, and operations of the train, and so on and so on, schedules being a really key t becse we wanted to make sure whatever we did did not affect the potential of getting the tunnel under construction on roughly the same time frame that we have today. i will turn this over to evsus gygi. there were other components that we initially looked at, and i will just close myart by saying number five here is one i really want to emphasize. when we started the study, we were looking at the possibility that whether or not, i should say, we were asking ourselves the -- whether or not the removal of a portion of interstate 280 would help in this overall transit system. obviously, that was extremely controversial, but we felt we needed to answer that question