The eastbound lanes of Interstate 10 were closed Wednesday morning after a bicyclist was struck and killed by a tractor-trailer near Casa Grande.
Arizona Department of Public Safety officials said the truck was traveling east in the right lane of I-10 about 9:30 a.m. when he spotted a man riding a bicycle in the emergency lane.
The driver switched from the right lane to the left to give the cyclist more room. But the bicyclist decided to cross the freeway and ran right in front of the truck, DPS said.
The truck struck the bicycle as it veered into the left lane, and the bicyclist was pronounced dead on the scene when medical personnel arrived. His identity has not been released pending notification of next of kin.
The trucker, whose identity also has not been released, pulled over onto the shoulder, and a DPS officer came upon the scene a few minutes later.
Two Casa Grande Fire Department fire engines and a battalion chief were dispatched but were called off after medical teams from Eloy arrived, Casa Grande police spokeswoman Laura Martinez said.
Arizona Department of Transportation spokeswoman Cydney DeModica said bicycles, motorized bicycles and motor scooters are prohibited on most freeways in Arizona.
Signs are often posted on on-ramps barring them on freeways, DeModica said.
Eastbound I-10 was closed until about 11:30 a.m. while DPS diverted traffic to Trekkle Road.
The case is being investigated by DPS.