DES MOINES — Fewer people have died on Iowa’s roads this year than last, but the state still has averaged roughly one traffic fatality per day in 2011.

Iowa Department of Public Safety Commissioner Larry Noble shared those statistics Monday, coupled with a caution for drivers who will share the roads with farm vehicles during the harvest.

It also comes the end of a spate of high-profile traffic fatalities in the state, including a volunteer Firefighter Michael Collins who was hit while directing traffic near Shelby, Iowa State Trooper Mark Toney who died in a single-car accident near Indianola and four elderly women who were killed when driving back from a 95th birthday party in West Des Moines.

“It has been difficult to see so many die on Iowa’s roadways over the last few weeks,” Noble said during a Statehouse news conference with Lt. Gov. Kim Reynolds. “Losing Trooper Mark Toney was particularly hard for the Department of Public Safety and the state patrol. But make no mistake, losing one life, any life in a car crash, is one life too many.”

Noble and Reynolds attended Toney’s funeral Saturday in Ankeny.

So far, 236 people have died in traffic fatalities this year. Last year, 390 people were killed on the roads.

Reynolds said drivers need to be especially aware of sharing the road with farm machinery during the fall and not assume that farm implement drivers will be able to pull over to let cars and trucks pass.

“Motorists may have more difficulty in navigating around farm equipment when the sun is rising and setting,” Reynolds said.

Last year, there were 208 crashes involving farm equipment, resulting in six deaths and 14 major injuries, according to information from the Iowa Department of Transportation.

The exact circumstances of Toney’s single-vehicle accident remains under investigation, Noble said. So far, investigators aren’t certain why the officer’s car left the roadway and rolled into a ditch before it burst into flames, he said.

An autopsy determined that Toney didn’t have a health issue, such as a heart attack, before the accident, he said.

“We have a crash investigation team and our best investigator on this, but it will take several weeks and we look forward to determining a cause, but we may never know,” Noble said.