It seems like you can barely drive a mile without seeing them: the shredded remnants of truck tires on the highway.
They can be a hazard, especially to motorcyclists. And with temperatures peaking, tire debris from 18-wheelers called "gators" in the trucking industry are becoming a more common sight on Sacramento's freeways.
Rochelle Jenkins, a spokeswoman for the state Department of Transportation, said that gators must be picked up by hand and have been keeping maintenance workers busy.
"We have sweepers, but actually, the blown tires are too large for them," said Jenkins. She said maintenance workers told her that gators are a constant problem that can keep them occupied for most of the day.
The origin of gators is in dispute especially the idea that most gators come from capped or retreaded tires. Retreading is a process that saves money by shaving down old tires to their casing and attaching and bonding a new exterior.
"On these extremely hot days, the adhesive that holds these treads together gets hot enough that they lose adhesiveness," said David Decker, the director of operators at the Western Truck School in West Sacramento.
But Rod Stevenson, a manager at North State Tires in Yuba City, said retreads are economical, can double the life of a tire, and if manufactured properly, are just as safe as new tires.
He sells new tires, which can cost up to $600, and retreads, which are under $200. Problems arise from disreputable retreaders who take advantage of the lack of regulation and make tires that fall apart within weeks, he said.
They "don't take the extra steps that we do," such as X-raying tires for flaws and refusing to retread old tires, he said.
"People oversimplify it. And I completely understand it," said David Stevens, managing director of the Tire Retread and Repair Information Bureau.
He said gators also come from regular tires that blow out.
Michael Shaw, spokesman for the California Truckers Association, said debris happens because truckers travel so many miles and the big rigs have so many tires.
The key is trying to prevent blowouts: Drivers could be held liable if a blown tire damaged property or hurt someone. "Proper maintenance of our vehicles is critical to our success," he said, adding that truck drivers are required by law to inspect their vehicles every time they set out on the road.
"It's more than just going up and kicking the tires," said Decker, who drove big rigs for 17 years. "They're running their hands over them to look for cuts, abrasions, and bulges."
Stevens and Shaw both cited a 2008 study from the National Highway Traffic Safety Administration that showed that retreaded tires were no more likely to blow out than new tires. The study also indicated that tire defects occur more frequently during summer.
The same study estimated the impact of gators on America's highways. It reported that less than half a percent of crashes and fatalities were prompted by drivers swerving to avoid debris, and an average of 55 people were killed per year in truck accidents where the trucks were found to have tire damage.
Statistics maintained by the California Highway Patrol make it hard to tell how big a problem gators are in California, but spokesman Adrian Quintero said they don't come close to being the biggest risk facing California drivers.
"Ladders are the No. 1 call we get," said Quintero. "Mattresses are a close runner-up after that."
Regardless, Quintero said any road hazard should be considered an emergency. "Dial 911 immediately and give us that information," he said.
Call The Bee's Jack Newsham, (916) 321-1100. Follow him in Twitter @TheNewsHam.