In an area where flooding is possible and current conditions warrant, CSX and Norfolk Southern may implement 40 mph speed restrictions in the affected area.

Both CSX and Norfolk Southern policies follow the same concept most of us do when driving in heavy rain: slowing down enables the engineers to operate through areas with limited visibility. Most importantly, should deep water cover the tracks, or if a section of track is washed out, a slower rate of speed will allow the engineer to slow or stop the train.

Speed restrictions during in flash flood warnings conditions, like heat restrictions, are put into effect for safety reasons. This rule is put into effect because heavy rains can wash away parts of the ballast (the rocks that support the tracks).

The Manassas line is especially prone to this since the conditions that cause flooding are more prevalent. Once imposed, flood-related speed restrictions will remain in place until the tracks can be properly inspected. So even though it may be sunny outside, if the tracks haven't been fully inspected yet after a storm the speed restrictions will remain.