The diverging diamond interchange, or DDI, in Round Rock is almost complete and already open to traffic. And after more than a year of planning, city officials are moving forward with plans to widen University Boulevard east of the DDI.
The Texas Department of Transportation officially opened the DDI crossover to traffic Nov. 20, substantially completing the state’s $6.6 million renovation affecting access to University and the I-35 frontage roads.
“All in all, we’re very satisfied. What is there today is the TxDOT project in its entirety,” said Round Rock Transportation Director Gary Hudder.
Hudder said the city has been working on an expansion project for 18 months to widen University between Sunrise Road and University Oaks Boulevard. He said the expansion will tie into the DDI.
Williamson County will serve as a regional partner for the city-led expansion by paying $5 million toward the total $15 million cost, and Hudder said a number of actions need to be completed before expansion can begin.
“We have to engage so many other entities. We are in the process of doing right of way acquisitions now, and then we’ll begin working with third-party utility-relocation services,” he said. “In a perfect world, we would hope to do utility relocations this year and begin construction in 2017.”
Hudder said the DDI design, which spans I-35, with RM 1431 to the west and University Boulevard to the east, has been somewhat confusing for drivers, but he said city officials are beginning to hear favorable comments.
Kim Perez, a real estate agent and resident of the area, said the changes take some familiarization. She said additional clarity for DDI access is necessary, and there is room for improvement for the westbound lanes of traffic.
“I live right off [FM] 1431 just west of the intersection. I’ve tried to remain open-minded about it, especially during construction, but I think there’s a lot of confusion about people merging where they’re not supposed to merge,” Perez said. “The striping is not clear, and it’s so different from what people are used to. For those of us who live there, it’s been great; I’ve been able to get through there a lot faster, but we do need to be cautious.”
The DDI design is intended to reduce the number of starts and stops drivers make compared with traditional intersection designs. Left-turning vehicles do not have to conflict with oncoming traffic, and the DDI is intended to reduce backups by allowing a greater number of cars to flow efficiently through the cross-sections.
TxDOT Public Information Officer Kelli Reyna said substantial completion is different from full project completion.
“We did reach substantial completion, technically considered when the intersection is open to motorists,” Reyna said.
Full project completion will occur in the spring because TxDOT crews still have work to do at the intersection.
“We still have to repave and restripe, but that can’t occur until the temperatures are consistently warm enough so the asphalt can stick to the roadway,” Reyna said. “While technically the intersection is open to traffic, it is not 100 percent complete.”
Although official traffic studies of the project’s effectiveness are still under review, Reyna said TxDOT believes everything is working well and going as planned.
“The result is a two-signal phase of operation, which results in probably a 50 percent reduction in travel time. This is different, the first of its kind in the area, and we feel it’s a great improvement in the way traffic is able to move,” Reyna said. “We just ask the public to pay attention to what the road is telling you to do, as it may seem awkward at first.”