A Cook County jury has awarded more than $54 million to a man who sustained head, neck and knee injuries after a semitrailer rear-ended his vehicle on an Indiana interstate.Plaintiffs James Denton and his wife, Theresa, of Oak Lawn, sued David L. Johnson, the truck driver, and Universal Am-Can Ltd., Universal Truckload Services Inc. and Louis Broadwell LLC, Johnson’s employers, in 2015, alleging Johnson was negligent when he failed to slow down to avoid a crash as traffic unexpectedly changed.Theresa Denton was not …