This meeting was held to discuss flooding and traffic congestion at the US 17-Main Road intersection, specifically the merits of the “flyover” vs “superstreet” options. The subcommittee includes Senators Campson and Thurmond and Rep. Robert Brown. The meeting was not heavily attended—about 25-30 people. The chair took 5 or 6 comments from the floor, but most of the input came from transportation and engineering experts from SC DOT (Robert Cross) and Charleston County (Jim Armstrong). My impressions are:
1. Neither the superstreet nor flyover will, by itself, solve the flooding problem that occurred earlier this month. That will require raising the Main Road bed and improving the drainage in certain spots, especially under the CSX tracks. Mr. Cross said that not only are the drain pipes under the CSX too small by today’s requirements, but they were also partially clogged by flood debris.
2. Mr. Cross said that SC DOT has plans to raise the Main Road bed soon—he hopes to have it done by Christmas. (He actually told me this as an aside after the meeting. The subcommittee didn’t pursue this issue; they focused mainly on the superstreet/flyover question). He also said they have cleared the debris and are in discussion with CSX about increasing the drain capacity.
3. The other major problem at that intersection is the congestion caused by left turning traffic. The superstreet plan would address this by devoting multiple lanes to turning traffic, although left turning traffic would first turn right, then make a U-turn at a signaled intersection about a quarter mile up the road. Mr. Cross said this arrangement would allow better synchronization of signals and therefore more efficiently move traffic. He also said this design is modeled on several US-17 intersections near Wilmington, NC that work quite well.
4. Since the flyover is an idea, but not an assigned project, no engineering or planning work has been done on it. It’s not even clear which road would “flyover” the other, although Mr. Cross said he assumed it would be a US-17 overpass. Therefore there was no discussion at all on how the left turning traffic congestion would be handled.
5. The superstreet is an approved project with funding—they are presently in the process of getting rights of way. They have a fairly definite cost estimate of $3.5 million and a two year timetable, depending on how long it takes to get rights of way. The flyover is way more uncertain. Mr. Armstrong of Charleston County estimated a 6-8 year time to completion at a $60 million cost, but that sounded very much like a SWAG and if you were forced to bet on the over/under, smart money would be on the over.
6. After about 45 minutes of discussion, Rep. Brown made a motion to recommend to Charleston County Council the flyover instead of the superstreet. The motion passed unanimously and will be forwarded to County Council Sept. 24.
7. Everybody that spoke from the floor was in favor of the flyover. It’s my impression that the counter intuitive nature of turn right to go left was off putting. I also spoke, but not in favor of either—I said I hoped that they could make a definite decision and move on it rather than the continued waffling that has characterized road discussion for the past 15 years.
8. The I-526 extension came up for some discussion. People speaking from the floor, except me, were opposed to it, and when asked were quick to respond that I-526 has nothing to do with the flooding or congestion at US-17 and Main Road. I think the subcommittee agreed with the first part, but not the second.
9. One of the speakers from the floor is an attorney representing the Coastal Conservation League; she said the League was in favor of the flyover option. Sen. Thurmond asked her if the League’s interest had to do with the hope/expectation that monies earmarked for I-526 would be diverted to the flyover. She danced around the question nicely, but basically said yes.