A federal jury awarded $18.6 million to the wife of a Canadian truck driver who died after a collision with a tractor trailer on Interstate 80 in LaSalle County.But the plaintiff, Natalia Volkova, will recover $15 million following a high-low agreement the lawyers entered into after closing arguments. The high was $15 million; the low was $4 million.A verdict was reached Thursday after a trial before U.S. District Judge …