How fast is too fast?

Since the end of 2008, two quiet stretches of Interstate 15 through southern Utah have had speed limits of 80 miles per hour.

Each section of road -- the first from south of Kanosh to near Fillmore; the second between Scipio and Mills -- spans about 18 miles and previously had caps of 75 mph.

The 5 mph increase caused drivers to go 2 to 3 miles faster on average, reported Carlos Braceras, deputy director for the Utah Department of Transportation. The bumped-up cap caused fewer speeding violations, slightly higher speeds but no increase in accidents, he added.

Rep. Janice Fisher, D-West Valley City, voiced reservations about upping the limit.

"We took a road trip to Bryce Canyon," Fisher said, "and these people were going faster than 85 mph -- you can take that to the bank."

"And isn't it true that you're more likely to get killed in a crash, the faster you're going?" Fisher added.