A semi driver went off the roadway for unknown reasons hitting the concrete barrier wall which caused a traffic back-up overnight until early Monday morning. Preliminary investigation revealed at approximately 1:40 a.m. Monday morning, a Volvo pulling a rail container, driven by a 44 year old from Florida, was south bound on I-65 at the 241 mile marker (this is one mile north of the Lowell exit) in the right lane when the semi left the roadway for unknown reasons. The semi struck the concrete barrier wall that separates south bound I-65 to the south bound I-65 truck scales. This crash caused all south bound lanes to be shut down for over an hour. The left lane was open to traffic shortly after that. The driver was taken to a hospital in Crown Point for non-life threatening injuries. A hazardous material clean-up company was called to the scene because of the diesel fuel leakage on the roadway and shoulder. The roadway was completely re-opened at around 9:20a.m.