TxDOT engineers plan small steps before major expansion on I-35

Traffic engineers with the Texas Department of Transportation know how they want to spruce up the Travis County corridor along Interstate 35, but they aim to start small. At a media workshop Tuesday, officials went over TxDOT’s short- and long-term ideas for the state’s most congested stretch of freeway, while Austin State Sen. Kirk Watson talked about the need for more money.

 

Watson said the state needs to find new money, perhaps from a motor vehicle fee, car sales taxes or the gas tax. Even though the gas tax proceeds are Intended for road-building,  lawmakers often divert such funds for other purposes.

 

“If we are going to continue to be the state that those in control of the Capitol say they want us to be,” Watson said, “which is a state that has people coming in droves every day – and when they come, they typically show up in their car, and we continue to brag about what Texas offers in terms of quality of life and our economy – we’re going to need to assure that quality of life and the economy can thrive with transportation.”

 

In the meantime, TxDOT has come up with a series of small, relatively affordable projects to build while it waits for funds to add two travel lanes to I-35. The department hopes that by getting small projects shovel-ready, it can spring to action as money permits. Officials say even localized changes could make a difference, since some 85 percent of trips on I-35 in the Austin area start or end within Travis, Hays or Williamson counties.

 

At the Parmer Lane intersection, TxDOT is currently building a new northbound collector-distributor road, essentially a funnel for through traffic. Plans for Parmer call for a diverging diamond intersection, which in turn guide vehicles along curving paths that reduce the need for traffic signals. This should increase the intersection’s capacity by 30 to 50 percent, according to engineer Steve Miller, vice president of infrastructure firm HNTB.

 

More short-term plans include three roundabouts at Wells Branch Parkway and one each at Howard Lane and 51st Streets. The St. John’s Avenue intersection would gain collector-distributor lanes and U-turns on the bridge. Bridges are set for reconstruction at Oltorf Street and William Cannon/Stassney, among other changes at those junctions.

 

Over the long-term, a full reconstruction is in the works for I-35 between Holly Street and Martin Luther King Jr., Boulevard. Miller said the plan is to either elevate or depress the expressway at Cesar Chavez Street. They would also remove four of eight existing ramps between Holly Street and 12th Street and add new lanes to guide through traffic across Lady Bird Lake.

 

Whether to go under or over Cesar Chavez is still uncertain. Depressing the main lanes would allow the city to build grade-level “caps” atop I-35 between Willow Street and 12th Street, which could host a park, Miller said.

 

Miller also talked about fitting new lanes into the stretch between MLK and Airport Road, bordered on the east and west by the University of Texas and the Texas State Cemetery. Engineers initially wanted to add lanes to the upper decks, but the 1974-vintage decks can’t handle the weight. So they plan to more or less gouge out the sloping sides of the lower deck in order to squeeze in extra lanes.

 

Most of these ideas are still in the planning stages. Even small projects could take years to advance to construction. The problem is money. The Travis County projects alone – both short- and long-term – carry a price tag as high as $2.2 billion in 2020 dollars.

 

“We have no construction funding,” Miller said.

 

In fact, to merely maintain roads at the current levels of congestion, TxDOT needs $5 billion more than it has. Proposition 1 on the Nov. 4 ballot asks voters to approve diverting money from the state’s Rainy Day Fund to TxDOT to build new roads and maintain old ones. That could amount to $1.4 billion in the first year, which still leaves TxDOT short.