Traffic crews trying to get a Maryland highway ready for winter put down the wrong chemicals Friday morning. The error caused slick conditions on the road and at least 10 accidents. Dave Buck with Maryland State Highway confirms the bad mix of chemicals were applied near Georgia Avenue on I-495. Crews were supposed to apply only salt brine, but liquid magnesium was somehow mixed into one batch of the brine. Two trucks at different locations were loaded with the brine-magnesium mixture. The contractor’s trucks with the bad mixture has been identified. Maryland State Highway is investigating. Trucks with only salt brine went over the affected roads again to try and correct the problem. The area affected with the bad mix included the overpasses and bridges on 495 between Route 650 and Route 270.