I've forgotten some of the talking points, but I believe one major concern was a rail spur to support rail transport of containers, and the traffic.
What really concerns me is what is planned for Red Bluff Rd.
Red Bluff is the most direct route to 146 from Beltway-8. My neighborhood is at Red Bluff and 146.
There was a lot of fur flying over this project, but you can't stop 'progress'. The truth and fiction of it were often blurred.
The new rail line would have run next to Ellington airport and skirted the north side of Clear Lake City before ending within the Bayport industrial complex just east of Red Bluff, about midway between Bay Area Blvd and Fairmont Pky. It was cancelled after an agreement was reached (in part brokered by Tom DeLay) for the 2 competing railroads to share an existing line that runs along Hwy 225 and the Ship Channel industries.
As to the Red Bluff freeway, it was at one time killed but appears to be resurrected as a 4-lane tollway that will begin construction in 2009. Some of the info I've seen suggested it might run entirely down Fairmont Pky, instead of the original plan to turn southeast down Red Bluff. However my gut says it will run on the latter corridor. Interesting that the port's Bayport master plan map doesn't show a freeway interchange for Red Bluff & 146, and all ramps into and out of the port only connect to/from the north side of 146. But I wouldn't rule out them adding ramps from Red Bluff both into the port and southbound onto 146.
Bayport master plan:
http://www.portofhouston.com/pdf/genifo/POHA-BayportMasterPlan.pdf
Bayport website:
http://www.zachrybayporteam.com/live/home.htm
Port of Houston website:
http://www.portofhouston.com/geninfo/bayportproject.html