Some like it HOT.

More drivers are warming up to the Valley Freeway’s (HOT) high-occupancy toll lanes, giving engineers and transportation leaders hope that the project eventually will expand to further ease gridlock on one of the state’s most congested corridors.

It appears more commuters, especially those who prefer to avoid a messy I-5 experience to work, school or play, have hopped onto State Route 167’s far left lane to buy extra time.

What began as a four-year pilot project in 2008 has become a successful enterprise.

The SR 167 HOT lanes have accelerated into the black.

“I can say, as we closed out February, we’re continuing to see growth in usage as well as revenue,” said Craig Stone, toll division director for the Washington State Department of Transportation. “The lanes are doing what they were designed to do – reduce congestion and improve travel times for everyone traveling on this corridor.”

HOT lanes were established to study how variably-priced, electronic tolling can ease traffic congestion on SR 167 – an 11-mile northbound stretch between Auburn to Renton, and spanning eight miles the other way. Solo drivers with a Good To Go! transponder were offered the choice to pay for a faster trip in the carpool lane when extra space was available.

According to the WSDOT’s latest performance summary released in December, the HOT lanes revenue exceeded expenditures by $12,000 in the fourth quarter of fiscal year 2011. Recent data shows the upward trend continuing into 2012.

HOT lane revenue increased 35 percent in fiscal year 2011, generating $750,000, compared to $560,000 that was generated in fiscal year 2010, the WSDOT report said.

Toll collection costs also have decreased, the report said.

All revenue generated by SR 167 HOT lanes is reinvested in the Valley Freeway corridor.

“Revenue covering the HOT lanes operational cost is frosting on the cake,” Stone said. “The once underused SR 167 HOV lanes are now a workhorse.”

In February, the average trip cost $1.40, up from about $1.25, because more motorists are using the toll, Stone said. Drivers also experienced about a 10-minute travel time savings in peak commute hours, he said.

But while the HOT lanes are by no means a solution to the Valley Freeway’s typical workday congestion, the project is doing what it was designed to do.

“It’s allowing us to get the most out of every square foot of pavement we have out there,” Stone said. “We’re making every lane as efficient as possible.”

The HOT expressway soon will stretch farther south, from Auburn’s 15th Street Southwest exit to Pacific’s 8th Street/Jovita Boulevard exit in Pierce County. The federally-funded extension will provide another alternative route for south Auburn commuters.

Stone said the project is in the final steps of design.

Long term, the WSDOT is considering putting in for a federal grant to extend northbound lanes.

Tolls are taking the lead on Puget Sound’s main corridors, be it 167 or the 520 or Tacoma Narrows bridges.

The WSDOT also has conducted a I-405 and SR 167 Eastside Corridor Tolling Study, which explores the potential of developing a critical freeway alternative to I-5.

Despite high gas prices and increasing tolls, more drivers are buying into the system, paying more to get to where they need to go.

It is the reality of the situation, especially for a cash-strapped state with major transportation problems and few funding mechanisms.

As Stone points out, more than half of the commuters who use the HOT lanes purchased price-reduced transponders in anticipation of the 520 toll.

Despite skepticism, studies show support for HOT lanes among all income levels.

Drivers will have the choice – pay more, save time and avoid fewer bumpers.

Tolls, and more tolls, are here to stay. And, if the experience of Washington and other states says anything about the future, tolls stand to increase. More tollways promise to pop up here and elsewhere to address and sustain stretched infrastructure, be it new or worn.

HOT lanes are just part of the landscape.