As the Valley wraps up one 20-year building program and heads into a second generation of construction, the key feature will be widening and improving freeways to compete with growth.

Some freeways will be added, but the focus will be on raising the amount of traffic that existing roads can handle. As unrelenting growth rapidly pushes out the edges of the metropolitan area, new freeways turn into congested traffic jams as soon as they are completed.

"That's the challenge that we face," said Doug Nintzel, spokesman for the Arizona Department of Transportation. "It appears that we'll always be behind the growth curve in the Valley."

But although freeway building in the Valley can be a frustrating game of catch-up, road builders should be able to avoid the delays and difficulties that bedeviled the first 20-year freeway program, planners believe, because of hard lessons learned and experience gained.

With today's complex network of freeways connecting most of the Valley, it may be hard to recall just how hopeless things appeared in the early 1990s, when it looked like the freeways would never be built.

Drivers had voted in 1985 for a half-cent sales tax to fund a 20-year transportation program that included 231 miles of freeways, but 10 years later, they were still waiting for the cement to flow. Other than a few scant and scattered miles of new freeway, not much was happening.

Critics were declaring the Proposition 300 freeway plan a grandiose failure, blaming poor management and overly optimistic funding forecasts. Beleaguered transportation officials cited an economic downturn that had robbed them of funds, plus burgeoning land prices for rights of way.

A massive effort in political, financial and construction activity was cranked up in 1996, so that today, a major portion of the Maricopa County freeway system envisioned by planners and passed by voters in 1985 has been built or is close to completion.

"Don't take what's been done for granted," Nintzel said. "Those of us who've been in the Valley since the 1970s and '80s have seen what we've been through."

When the ambitious 1985 building plan finally draws to a close, 147 miles of new freeways will be under our wheels, 84 fewer than planned, and a new 20-year program will begin under Proposition 400, the 2006-2026 Regional Transportation Plan passed by voters last year.

The end of the 1985 construction program will actually come in 2007, about two years late, with the planned completion of the Santan and Red Mountain segments of Loop 202 in the East Valley.

At that point, say officials at ADOT and the Maricopa County Association of Governments, the regional planning body, there will be a seamless transition to the new plan, which includes some of the unbuilt highways originally in the old plan.

"I think with the completion of Red Mountain, there might be a little ceremony that will close the books on Proposition 300," said Eric Anderson, MAG transportation director. "Then we'll take a deep breath and go forth."

Proposition 400 allots $5.9 billion for freeway projects, about 57 percent of the total tax package. The money starts flowing in March."You shall see a lot of activity after that," said Paul Ward, MAG transportation planner. "This (funding) has provided us with a lot of certainty for what we'll be doing."

The new freeways and improvements should provide some relief for commuters, Nintzel said, but nobody expects the freeway construction to do away with rush-hour congestion.

"Obviously, we're going to grow in the number of vehicles, so we have to manage that," Nintzel said. "There's just so much you can do with freeways."

One of the important aspects of Proposition 400, he added, is that it includes important mass-transit components that could make a dent in congestion.

"We're going to have to see what happens with things such as adjusted work schedules, carpooling and transit in order to create situations where there are fewer vehicles on the freeways at any given time," he said.

The Proposition 400 plan does address some of the Valley's most notorious bottlenecks, such as the infamous Broadway Curve on Interstate 10 in Tempe and the increasingly backed-up lanes of Interstate 17 in north Phoenix. More lanes will be added to those stretches.

The next 20-year round of construction will complete nearly all of the original freeway map of 1985, including Loop 303 in the West Valley and the South Mountain segment of Loop 202, which will provide a Phoenix-bypass route to the south for I-10.

The first five years of construction, called Phase 1, will begin with a small step, construction of an I-10 interchange at Bullard Road in west Phoenix that should be completed in 2007. A new interchange for Bethany Home Road on the Agua Fria Freeway section of Loop 101 should follow shortly thereafter.

After that, road builders will set their sites on widening and adding high-occupancy vehicle lanes to the Pima Freeway segment of Loop 101, U.S. 60 in the East Valley, and I-17 from Loop 101 to Carefree Highway.

HOV lanes will be added to Arizona 51 from Shea Boulevard to Loop 101 and on the Red Mountain segment of Loop 202 from Loop 101 to Gilbert Road, and on I-10 south of Loop 202 to Riggs Road. Lanes will be added to I-10 in the West Valley, and to Loop 202 from Arizona 51 to Loop 101.

"There are $2.8 billion in (freeway) projects for the first five years," Anderson said. "That's a record."

Drivers will experience some inconvenience because of construction, Nintzel said, though it should be tolerable because much of the roadwork will be performed in the medians and on the shoulders of the freeways.

Despite the ambitious schedule, MAG and ADOT should be able to cope with the construction demands, Anderson said. Unlike the early years of the first freeway program, the agencies are now equipped with the know-how to make it all come together.

"ADOT had very limited experience in building urban freeways," Anderson said. "I think that many of the challenges we had are understood a lot better.

"We know a lot more and have a more realistic view of what it takes to build in the urban environment."