But drivers who say their paychecks are getting smaller and smaller as Las Vegas Strip traffic gets more congested say their next stop will be the Clark County Commission's office to find out what can be done about mobile billboards that disrupt the traffic flow.

"There are about 200 trucks clogging up the Strip," said driver George Zeigner of A-North Las Vegas Cab. "I'm not even sure if trucks are even supposed to use the Strip, but I know that those mobile billboards result in a lot of congestion."

After raising the issue at the Taxicab Authority's March 25 meeting, the drivers decided to take the matter to Commissioner Chris Giunchigliani, whose district includes the Strip north of Flamingo Road.

Giunchigliani said she has been interested in the traffic issue since she joined the commission.

"I've had numerous calls from constituents about mobile billboards slowing people down, so it's something that needs to be addressed," she said.

Giunchigliani said she is in the process of gathering information and determining whether its simply an enforcement issue or if new ordinances are necessary.

"I want to look at the whole thing," Giunchigliani said. "It's clearly a safety, traffic, congestion and air quality issue. I also want to look at the brightness of these signs on the Strip because that could be a safety issue.

"I really want to get the public to participate in this discussion, so I'm reaching out to the public for testimony and I'm researching what other states have done. Some states have prohibited them but I'm still looking at everything before making any decisions about them," she said.

As far as one Las Vegas company is concerned, issues involving mobile billboards have been around for a long time and the clear solution to the problem is enforcing existing laws.

Marla Letizia, president of Big Traffic, Southern Nevada's dominant mobile billboard company, said not only would she welcome a dialogue with Giunchigliani, but she'd welcome enforcement because she feels it would help her company.

"I've been asking for better enforcement for years," said Letizia, who said most of the violations involve unlicensed out-of-market competitors who run their vehicles on the Strip whenever there's a big convention in town.

The 200-vehicle estimate offered by the cab drivers is likely an exaggeration - Letizia's company is the largest of three that operate in Clark County and she only has 13 trucks in her fleet.

But Letizia said she and her company take the brunt of the public criticism about mobile billboards because her company is the largest. She said she helped draft the original county ordinances regulating mobile billboards.

Letizia cited a Clark County ordinance that is frequently violated by companies from outside the county. The county ordinance says, "No vehicle shall display or exhibit any signage that contains moving or flashing lights or animation of any kind." Yet she frequently sees vehicles on the Strip that project video images.

"I'll give you another example of a real safety issue," she said.

Many mobile billboards on the streets are illuminated with lights that are powered by gasoline or diesel generators. Letizia said those generators could explode like a bomb if such a vehicle were involved in a collision.

Letizia said one of her employees invented a friction-drive system that uses the rotation of the vehicle's wheels to generate power to a set of on-board batteries that illuminate the signs.

Letizia also said her company strictly monitors wind velocity and a mobile billboard driver's speed. If wind gusts reach 25 to 35 mph, a driver has the option of pulling off the road. When sustained winds reach 30 mph, a mandatory order to pull off is issued.

Some companies allow their drivers to continue in high winds, Letizia said, and vehicles that tow signs behind a truck are even more dangerous in high winds because trailers can jackknife or fishtail in traffic.

Big Traffic uses a satellite-assisted global positioning system to monitor the speed of all drivers. If a driver exceeds a posted speed limit, a traffic monitor is alerted and the driver can be disciplined.

Letizia also said her company refuses to display ads for strip clubs or escort services because of the distraction they create and the confusion they cause among people who aren't aware that prostitution is illegal in Clark County. She said that's one of the ways that added enforcement could weed out some illegal or unsafe operators.

One of Letizia's local competitors, Mobile Billboards of Las Vegas LLC, takes ads from escort services. Representatives of the company could not be reached for comment.

Former Clark County Commissioner Myrna Williams was supportive of Letizia's efforts to find and ban illegal operators but when Metro didn't respond to calls for enforcement, she gave up the fight. Because the issue has been raised again, she said she plans to contact Giunchigliani.

The taxi drivers' raising of the mobile billboard issue was the first of two airings of dissatisfaction in public settings.

On March 31, about 200 drivers and supporters demonstrated on Las Vegas Boulevard on cab allocations by the Taxicab Authority. The demonstration was a pre-emptive strike in the authority board's annual review of allocations scheduled in the summer.

Drivers marched with signs and passed out leaflets at Las Vegas Boulevard and Fashion Show Lane. While drivers said they would not disrupt traffic, there were reports of motorists being blocked on the Strip.

A similar protest occurred in 2005 in response to legislation banning strip-club payouts to cabbies that transported customers to the clubs. More than 3,100 cabs are regulated in the county.

According to statistics issued by the Taxicab Authority, the average number of taxi trips per shift fell 4.2 percent to an average of 20.8 trips from 2006 to 2007. But at the same time, thanks to rate increases approved by the board, revenue was up 7.9 percent during the same period to $319.6 million.

But the bigger pie was split more ways - the number of shifts was up 7.2 percent resulting in increased revenue per shift of only 0.7 percent to $249.35.

Cabdrivers also point out that more revenue for the cab companies doesn't necessarily translate into higher tips and better pay for drivers. Drivers are hoping that with a shaky economy, the Taxicab Authority board won't increase the number of cabs on the road during the annual review.