WASHINGTON (AP) — Preliminary government data indicate highway deaths declined again last year, reaching their lowest rate on record when compared to miles driven.

The National Highway Traffic Safety Administration's early estimate of 2011 traffic fatalities released Monday says there were 32,310 deaths in motor-vehicle crashes, a drop of 1.7 percent from the previous year. That's the lowest number of deaths in more than 60 years.

The number of miles driven also declined by 1.2 percent. There were 1.09 deaths per 100 million miles traveled, down slightly from 1.11 deaths in 2010.

Safety experts have attributed the decline to a variety of factors, including less driving due to a weak economy, more people wearing seat belts, better safety equipment in cars and efforts to curb drunken driving.