California Highway Patrol officers have been weighing and inspecting commercial vehicles at the Conejo Inspection Facility on Highway 101 since 1975. But now, with a record number of trucks passing through its scales, officials say the aging facility could use some upgrades.

Sgt. Randy Klucker said outside weight displays are one of the biggest needs.

"Drivers have to leave their truck to learn how overweight their truck is," he said. "This causes a delay for them and for us. The traffic can get backed up quickly."

Lt. Steve Munday, who oversees operations at the facility, said the state Department of Transportation has budgeted for the outside display, and it could be installed within the next year. But as far as other improvements go, he won't be holding his breath, he said.

"The type of upgrades we'd really like to see would cost millions upon millions of dollars," he said, "and I just don't see Caltrans going for that."

Munday estimates 40,000 trucks pass through the scales on the northbound side and 35,000 on the southbound side each month.

"That's not how many are inspected here, though," he said. "We routinely inspect about 13,000 trucks a year — nearly 1,100 a month."

With hundreds of trucks passing through the scales daily, officers must work quickly and efficiently to move them along. As the trucks slowly drive through one of two lanes — one for empty trucks, one for loaded — officers check to make sure loaded trucks meet weight guidelines. Loaded trucks must drive slowly over the scale and can weigh no more than 80,000 pounds.

Trucks that meet the guidelines are passed through, while overweight trucks are stopped by officers and pulled out of service. The truck's company is called to send another driver out so the load can be split.

Sometimes, the weight load may be too heavy on certain parts of the truck's axle, and the drivers will have to shift the load.

All trucks are also checked for current inspection stickers, Munday said.

Trucks due for an inspection, done once every 90 days, must loop around the facility through a tight curve. Klucker said he would like to see the road redesigned because the loop means more hassle for the drivers and can also cause traffic to build up.

Once the trucks enter the bay, commercial vehicle inspection specialists begin the 15- to 20-minute inspection process by checking the driver's paperwork.

An officer will check the driver's license for violations or warrants, said inspection specialist Terry Russell.

"We've arrested 16 drivers here so far this year on miscellaneous warrants," Munday said, "and another five for DUI."

During the inspection, the specialist checks all the lights and wheels, looking for burned-out bulbs and serious cracks. They also inspect underneath the vehicle.

"We check everything — the frame, the axles, the air brake lines," Russell said. "Everything is bolted together down there so we're also checking to make sure it's bolted tight."

If the vehicle doesn't pass inspection, it is pulled out of service.

If the problem is mechanical, the driver has to wait for his company to send someone to fix it, Russell said.

Vern Burkhardt, who's been an inspection specialist for 10 years, said bad brakes or suspension problems are among the most common reasons a truck will be pulled out of service.

"We can't let those trucks go back onto the road with bad brakes," he said.

Charles Schaal, a truck driver from Spokane, Wash., who owns a truck that he rents to Allied Van Lines, was temporarily detained recently during his inspection. But he didn't mind.

"This one's voluntary. I always volunteer for my inspections so I don't get stopped when I really can't afford to lose the time," he said. "Plus, it's just a safety thing. They might find something I miss.

"I've never been pulled out of service," he added. "I take a lot of pride in keeping my truck well maintained."

CHP Capt. Cliff Williams said the service the inspection facility provides is invaluable. It's difficult to measure the number of deadly collisions the facility prevents, he said.

"It greatly enhances the safety for all motorists traveling down the Conejo Grade. The last thing motorists want is an out-of-control truck barreling down the Conejo Grade," he said.