This from a BloomberyBusinessweek article, Unlocking the Crude Oil Bottleneck at Cushing.
Cushing is now best known as a bottleneck for the energy industry: Oil rushes in, but trickles out. There are now more than 44 million barrels of oil stuck in Cushing, a record, and 60 percent more than was stored there just five months ago. Overall U.S. crude inventories now sit at a 21-year high.
Pipeline companies are racing to build new projects aimed at pushing more oil through Cushing toward refineries as part of a larger effort to revamp America's oil infrastructure. The first of those projects goes online this week when the flow of the 500-mile Seaway pipeline is reversed.