With North Dakota's substantial contribution (now ranked third in monthly production), the pipelines just can't carry enough oil, so there are unit trains and even haul trucks moving crude oil.
The 'discount' spoken of means oil production companies are getting paid as much as $30 less than spot for the oil (usually at par with WTI) at the wellhead because of transportation costs/issues.
Expanding the pipeline capacity by running additional lines alongside the existing ones does two things: Increases capacity, and dodges the EPA bullet by utilizing routes which have already been approved. Those lines will be north of Cushing, OK.
Which is the missing key datum. Parallel pipelines NORTH of Cushing make sense in avoiding the "environmental evil excuse" that the Obama socialists are using to stall things.
Now I wonder what "new" excuse they will come up with.