San Antonio’s Blanco Road and Loop 1604 to see traffic changes with new ‘diverging diamond interchange’

Officials said this change will allow crews to begin the final phase of construction that’s expected to be completed by late summer 2026.

SAN ANTONIO — Drivers will soon see changes when traveling on the far north side of San Antonio starting this week. 

TxDOT announced starting Monday, March 23 drivers will see a new traffic flow at Blanco Road and Loop 1604 as the intersection becomes a “diverging diamond interchange” (DDI), meaning traffic on Blanco Road will shift to the left side of the road when crossing Loop 1604. 

According to TxDOT, this change will allow crews to begin the final phase of construction that’s expected to be completed by late summer 2026. 

Officials said in order to start this new traffic pattern, a full weekend closure of the Blanco Road and Loop 1604 intersection is required. The closure is scheduled from Friday, March 20 at 9 p.m. through Monday, March 23 at 5 a.m. Access to local businesses will remain open. 

During this phase, drivers should expect the following:

  • Traffic on Blanco Road will shift to the left when crossing Loop 1604
  • Through traffic on Loop 1604 frontage roads must use the bypass lanes
  • Temporary traffic signals will be in operation
  • Barriers will be installed to allow for construction of concrete islands
  • Pedestrian access may be limited
  • Weeknight closures will continue as needed

For more information about the “diverging diamond interchange” or how the traffic flow will work, click here.

Original News Source