The decrease in coal traffic dominated rail news headlines last year. But another big rail-traffic story for 2012 was the increase in carloads of crude oil moving to the East and South, usually from North Dakota's Bakken Shale region.Crude-oil traffic more than doubled for U.S. railroads last year, reaching an all-time high. Railroads originated 233,811 carloads of crude in 2012 — a whopping 256 percent increase over 2011, according to the Association of American Railroads. Crude shipments represented 0.8 percent of all U.S. Class I carloads, up from 2011's 0.2 percent.Will the crude-by-rail growth trend continue through 2013? That's the topic of this week's poll on ProgressiveRailroading.com. You can answer the question by clicking here.