Armed with lessons learned from last year's polar vortex, the U.S. transportation and shipping network faces its first big test of the winter this week as harsh cold and dangerous wind chills buffet the Plains to the East Coast. Moving people and products has proved tedious but not impossible as upper Midwest temperatures topped out in the single digits to below zero Fahrenheit on Wednesday, with gusty winds making it feel like 20- to 40-below. Snow blanketed much of the eastern United States, with lake-enhanced accumulations of more than a foot in northwest Indiana and western New York. It is the coldest weather since the region was hit last year by a polar vortex, which is a mass of frigid air that typically only resides over the north pole. Midwest farmers delayed grain deliveries while hog farmers kept swine in warm barns. Plains feedlot operators sold cattle at higher-than-expected prices in weekly auctions early this week as beef packers scrambled to secure livestock struggling to retain weight in the bone-chilling cold. Commuter railroads warned passengers of service delays and advised riders to allow for extra travel time, while freight rail carriers prepositioned needed equipment and shortened trains to keep air brake systems working effectively. Chicago's Metra commuter line upgraded its passenger alerts system and spent more than $2 million on additional rail switch heaters and equipment to clear snow and ice from tracks. Still, the carrier warned of delays this week due to "temperature-related speed restrictions." Major freight railroads appeared more prepared after unprecedented service issues last year that impeded shipments of coal, grain and other goods. CSX Corp moved extra equipment into position ahead of the cold snap and had no problems, a company spokesman said on Wednesday. BNSF Railway Co is running shorter trains to ensure air brake systems work properly, a practice introduced after the western U.S. carrier experienced the brunt of service issues last winter, its spokesman said. Barge shippers hauling goods on the Mississippi River and its tributaries moved fleets further south to avoid getting stranded on ice-clogged waterways, shippers said. Ice is building on the Illinois River, which typically remains partially open to commercial navigation year round. "By the end of the week it will become an issue that will deter most barge lines from heading back into the river," one barge broker said. The Mississippi River at St. Louis has receded more than three feet since Monday because of upriver ice, prompting concerns that shippers may soon be forced to lighten loads or risk groundings. Midwest farm belt elevators and agricultural processors saw a slowdown in truck deliveries of grain, although no spot shortages were reported as many had accepted grain contracted for January delivery in late December. A Cargill Inc corn mill in Eddyville, Iowa, with the capacity to unload more than 500 truckloads a day reported daily deliveries of around 300 trucks on Monday and Tuesday. Many farmers kept swine buildings closed to conserve heat, which has contributed to heavier animal weights, an Iowa dealer said. But some processors were still working through a glut of animals following year-end holiday plant closures. Beef packers on Tuesday spent more for cattle and bought them earlier in the week than usual. Feedlots have been holding animals which have been losing weight due to cold and snow. "Weather has become an issue in feedlots from Texas through Nebraska. The extreme cold will cause cattle carcass weights to decline at a much faster rate than in prior years," said Hales Cattle Letter author David Hales in Amarillo, Texas. (Reuters)