HOUSTON -- Drillers are clamoring for more pipelines as crude oil production climbs, in the hope they can find some relief from truck and rail transportation that has increased costs in the North American oil patch. To meet that demand, pipeline companies are boosting the capacity and flow on their pipeline systems, often by hundreds of thousands of extra barrels a day. Enbridge Inc. plans to expand oil flows through pipelines that feed Midwestern refineries by 280,000 barrels per day, and capacity is set to increase on pipelines operated by Kinder Morgan Inc. and Plains All American Pipeline LP. But does adding more crude oil to a pipeline increase the risk of a rupture or spill? Go to story #1