ST. PAUL — Preliminary reports from the Department of Public Safety show the number of traffic fatalities on Minnesota roads decreased slightly in 2013.

DPS’s Office of Traffic Safety says preliminary data shows there were 375 traffic fatalities in Minnesota last year. Once all the data is in, that number is projected to rise to about 385.

That’s compared with 395 traffic fatalities for 2012.

Officials said the number of traffic-related deaths have declined 34 percent since 2004, when there were 567 deaths on Minnesota roads.

Once all the reports are in, officials expected drunken driving, not using seat belts, speeding and distracted driving will be primary factors contributing to the deaths.