Over the next few decades, San Antonio’s population is expected to grow by 2 million residents.

That poses problems for Loop 1604 – the outer highway encircling San Antonio – since the Texas A&M Transportation Institute already identified the northern portion as one of the most-congested corridors in the state. Travel times on Loop 1604 North currently range from 29 to 37 minutes. By 2040, traffic demand is expected to double, increasing travel times to as long as 113 minutes.

To reduce congestion and improve safety, the Texas Department of Transportation (TxDOT) undertook a $1 billion project to reconstruct and widen approximately 23 miles of the existing facility, expanding from four to 10 mainlanes while improving interchanges, ramps, auxiliary lanes, and other highway features. With the planned improvements, travel times on Loop 1604 North are estimated to drop by as much as 76 percent by 2045.

Originally a two-lane farm road, Loop 1604 expanded as development and traffic in the area increased. In the mid-1980s to early 1990s, TxDOT upgraded the roadway to a four-lane freeway between Interstate 10 West and Interstate 35 North. Subsequent projects in the 1990s extended the freeway.

As part of the Texas Clear Lanes initiative, the current Loop 1604 North Expansion project stretches from State Highway 16 to Interstate 35 in north Bexar County. When planning started many years ago, funding limitations necessitated toll lanes in the design. By the time the project started construction, TxDOT was able to remove the tolling component.

Because of the quantity and complexity of work, TxDOT divided the project into five segments and so far secured funding for the first three – two currently under construction and another anticipated to start in late 2022.

The first portion of Loop 1604 North under construction, Segment 1, extends from SH 16 (Bandera Road) to I-10. The $148 million, 5.3-mile project will add two general-purpose lanes and one high-occupancy vehicle (HOV) lane in each direction for a total of six new lanes. Work also includes reconfiguring auxiliary lanes and 20 entrance and exit ramps, as well as improved accommodations for bicyclists and pedestrians.

In April 2021, TxDOT awarded the low-bid contract for Segment 1 to Williams Brothers Construction Co., Inc., of Houston. Construction began in May 2021 and is expected to finish in 2024. Funding came through state and federal funds as allocated by the Alamo Area Metropolitan Planning Organization.

Since all the improvements for the Loop 1604 North project remain within the existing right-of-way and easements, “Some of the biggest challenges in construction are traffic control,” said Ismael Solalinde, P.E., Project Engineer for TxDOT’s San Antonio District. “We’re essentially trying to build a new road and bridges with as little traffic impact as possible while accommodating large equipment space.”

With safety as the top priority, “We try to keep an innovative mindset and constantly try to make upgrades and modifications to traffic control and pavement markings to improve safety,” Solalinde said.

Throughout construction, temporary traffic shifts and overnight lane closures on mainlanes and frontage roads, as well as temporary daytime and overnight ramp closures, maximize safety for drivers and workers. Generally, daytime work occurs Mondays through Saturdays, while nighttime work and any necessary lane closures happen between 9 p.m. and 5 a.m., Sunday evenings through Friday mornings.

In addition to updates communicated through social media, digital message boards along the corridor alert drivers in real time to lane closures, traffic congestion, and construction activity.

Because of the project’s location over the Recharge Zone for Edwards Aquifer – the primary drinking water source in central Texas – the contractor is required to comply with the Water Pollution Abatement Plan approved by the Texas Commission on Environmental Quality. As part of that, storage of hazardous materials is not permitted, Solalinde said.

In addition, “The contractor was required to prepare and implement a Contractor Waste and Management Plan to prevent, avoid, minimize, and clean up any spills associated with materials, waste, and equipment they bring onto the project area or generate within the project area, with an emphasis on chemicals and sanitary wastes,” he said.

To mitigate other impacts from the work, “The contractor proposed an innovative option with the use of precast bridge caps as an alternate design that will provide construction time efficiency, improved safety, and traffic control impact reductions with fewer lane closures,” Solalinde said.

While work continues on Segment 1, construction began on Segment 3 of the Loop 1604 North project in November 2021. That segment extends from I-10 to U.S. 281. TxDOT awarded the $233 million, low-bid contract to Zachry Construction of San Antonio and expects work to finish in 2025.

The $291 million Segment 2 project, between Segments 1 and 3, includes replacing the cloverleaf interchange at I-10/Loop 1604 with a five-level direct connect interchange. Construction for this segment is anticipated to start in late 2022 and finish in 2027.

“Our teams are really focusing on getting some work done on Segment 1 and Segment 3 on each side of the I-10/Loop 1604 interchange so when they start the interchange work, it will be more fluid and easier, with less impact for drivers,” said Jennifer Serold, Spokesperson for TxDOT’s San Antonio District.

With construction for the three contiguous segments eventually proceeding at the same time, “Language is included on the plans for contractors to plan ahead in order to coordinate with adjacent projects,” Solalinde said. “In addition, project managers from TxDOT and the construction engineering and inspection firm both attend meetings and always bring up potential conflicting or overlapping closures proposed by the contractors.”

TxDOT still needs to secure funding for the last two segments of the Loop 1604 North expansion. Segment 4, extending from the end of Segment 3 at U.S. 281 to Redland Road, is anticipated to let in 2025 at an estimated $130 million. The last piece, Segment 5, will finish corridor improvements from Redland Road to I-35. With a timeline yet to be determined, TxDOT estimates that project at $265 million.

Once complete, the planned improvements throughout the Loop 1604 North corridor will decrease travel times by as much as 80 minutes and promote multimodal transportation with the construction of continuous sidewalks and bicycle accommodations.

Owner – Texas Department of Transportation; Carlos Arcila, North Bexar Area Engineer, San Antonio District; Ismael Solalinde, Project Engineer, San Antonio District
Construction Engineering and Inspection – CP&Y, San Antonio
Contractor – Williams Brothers Construction Co., Inc., Houston