The Utah Transit Authority's current $1.75 basic fare for TRAX and buses is the same that riders pay in Denver and Portland, Ore., but will increase by 25 cents in July if board members vote for the surcharge at a 2:30 p.m. meeting. Sacramento Regional Transit already charges $2 a ride.

A yes vote today also would set in place a surcharge matrix that almost certainly would push the price of a UTA ride to $2.25 with a second increase later this year. The plan would give riders a three-month lag before imposing a quarter for every dollar that diesel climbs beyond $2 a gallon. That price already is above $4, meaning that unless the price declines this summer a second surcharge would start in September.

UTA officials say they must do something about the fast-rising price of diesel or cut bus service and maybe even delay development of new rail lines. The agency budgeted $15 million for diesel this year but now expects to pay $20 million. Already the agency has cut $2.7 million with a hiring freeze and reductions in contracts for janitorial and other services.

With diesel climbing more than a dollar a gallon in the past year - UTA projects it will use 6.1 million gallons in 2008 - everyone from airlines to freight shippers is looking to pass the costs along. It's a tricky proposition for public transportation, though, because riders already deal with regular fare increases.

"We have discussed the possibility of a fuel surcharge but we are not recommending that at this time, primarily because we had a fare increase in January and didn't want to go back with one so quickly," said Denver Regional Transportation District spokesman Scott Reed.

Light rail and bus rides in Denver cost $1.75, though longer-distance express and regional trips cost $3 and $4 respectively. A regional trip might cover the distance from Boulder to the south Denver suburbs, for instance.

UTA riders faced a 15-cent fare increase in January, and will pay another 25-cent standard increase next January. If diesel remained between $4 and $5 a gallon, UTA riders would pay $2.50 then. With a price above $5, riders could pay $2.75.

Instead of hiking fares, Denver is cutting the frequency of service on low-performing bus routes and on one light-rail line, Reed said.

Portland officials, though, will propose a fare hike today at a board meeting.

The base $1.75 light-rail and bus fare would go up either 20 or 25 cents in September, compared with a yearly September inflation hike of 5 cents, Tri-Met spokeswoman Carolyn Young said.

"We're not calling it a surcharge, because we don't expect [diesel prices] are going to go back down," she said.

The price increase probably will hurt ridership, though it's unclear how much, Young said. Transit agencies haven't updated their analytical tools to keep up with rapidly rising fuel costs.

"All of our models say that it will decrease ridership, but when drivers are facing $4 per gallon, the models sort of go out the window," she said.

Today's meeting is at UTA headquarters, 3600 S. 700 West, Salt Lake City.