The Utah Transportation Commission on Friday approved a plan that would allow motorists to pay $50 per month for unlimited access to the high-occupancy vehicle/high-occupancy toll lanes - known as HOV and HOT lanes - which now are reserved for buses and vehicles carrying two or more people.

"The whole way the lane works will have a fundamental shift," said Utah Department of Transportation spokesman Nile Easton.

The idea is to control congestion by moving more drivers into the HOV lanes, which now are underused.

Roger Borgenicht of Utahns for Better Transportation said that as a congestion-management tool, HOT lanes probably make sense but won't do what's necessary: Get more cars off the road.

"The more important thing is saying those HOV lanes are really for vans, buses and carpools," Borgenicht said. "Transit and multiple-occupancy vehicles ought to have priority."

To keep motorists from causing hazards as they cross four lanes of traffic to get in and out of the HOV/HOT lane, UDOT will repaint the lane stripes to allow entry and exit at just 15 spots along the 40-mile stretch of I-15 between 600 North in Salt Lake City and University Parkway in Orem.

The lane's entry-exit pockets will be 1,500 feet long, Easton said.

Car pools, buses and other multi-passenger transit will have to observe the same entry-exit rules. To be safe when entering and leaving the HOV/HOT lanes, "you do have to plan ahead," Easton said.

The stickers will probably go on sale in August after the Utah Department of Transportation repaints the lanes and puts up new signs, said Randy Parker, UDOT Region II director.

HOT lane motorists will have stickers on the front and rear of their vehicles. UDOT will purchase two Utah Highway Patrol cruisers and employ full-time UHP troopers to enforce the rules. Monitoring will be "strictly visual," Parker said.

The $50 monthly fee will pay for the program, including enforcement. "It's pretty close to break-even," Easton said.

Right now, the HOV lane regulations aren't well-enforced, Easton said, because given the other traffic problems they have to handle, UHP troopers don't consider them high-priority. "Violators use [HOV lanes] as a passing lane. That will have to stop," Easton said.

UDOT views the sticker program as a two- to three-year prelude to electronic tolling.

Under the electronic system, transponders in vehicles communicate with electronic checkpoints, which tally the distance driven. When HOT lanes become overly congested, electronic signs display the higher tolls, prompting thriftier drivers to move into the regular lanes.

Parker said UDOT will sell a minimum of 600 stickers on a first-come, first-served basis. Stickers will be available both on the Internet and at UDOT sales offices.

UDOT will survey the drivers to find out what stretches of I-15 they most often drive between 600 North in Salt Lake City and University Parkway in Orem to decide how to adjust the number of stickers to sell. If the surveys show that most of the purchasers drive only in Salt Lake County - which is unlikely - UDOT would curtail toll sticker sales, Parker said.

The hope is to maintain a 55 mph speed in the HOV/HOT lanes during peak commuter hours rather than the slower speeds commuters now experience in general use lanes, Parker said.

Plus, the more people who move to HOV/HOT lanes, the more room there will be in the rest of the interstate's lanes, where the posted speed limit is 65 mph.